{"id":308,"date":"2023-10-19T02:21:01","date_gmt":"2023-10-18T18:21:01","guid":{"rendered":"http:\/\/test.ccwifi.cc\/?p=308"},"modified":"2023-10-19T02:21:01","modified_gmt":"2023-10-18T18:21:01","slug":"%e6%b5%85%e8%b0%88-java-%e9%9b%86%e5%90%88-%e5%ba%95%e5%b1%82%e6%ba%90%e7%a0%81%e8%a7%a3%e6%9e%90","status":"publish","type":"post","link":"https:\/\/www.ccwifi.cc\/blogs\/2023\/10\/19\/%e6%b5%85%e8%b0%88-java-%e9%9b%86%e5%90%88-%e5%ba%95%e5%b1%82%e6%ba%90%e7%a0%81%e8%a7%a3%e6%9e%90\/","title":{"rendered":"\u6d45\u8c08 Java \u96c6\u5408 | \u5e95\u5c42\u6e90\u7801\u89e3\u6790"},"content":{"rendered":"<div>\n<p>\u5728\u7ebfwifi\u8dd1\u5305 \u91d1\u521a\u5305\u8dd1\u5305 cap\u8dd1\u5305 hccapx ewsa\u5728\u7ebf \u5c31\u6765 <strong><a href=\"http:\/\/ccwifi.cc\" target=\"_blank\" rel=\"noopener\">\u66f9\u64cdwifi<\/a><\/strong><\/p>\n<p>\u5404\u4f4d\u597d \u53c8\u89c1\u9762\u4e86 \u6211\u662f\u66f9\u64cd \u4eca\u5929\u7ed9\u5927\u5bb6\u5e26\u6765\u4e00\u7bc7\u65b0\u7684\u6559\u7a0b<\/p>\n<p>\u5e0c\u671b\u5404\u4f4d\u7ec6\u5fc3\u5b66\u4e60 \u4f4e\u8c03\u7528\u7f51<\/p>\n<\/div>\n<pre class=\"code-snippet__js\" data-lang=\"swift\"><code><span class=\"code-snippet_outer\">import java.util.HashMap;<\/span><\/code><code><span class=\"code-snippet_outer\">import java.util.Map;<\/span><\/code><code><span class=\"code-snippet_outer\">import java.lang.Object;<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">public class Test {<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;public&nbsp;static&nbsp;void&nbsp;main(String[]&nbsp;args)&nbsp;{<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;    Object o = new Object();<\/span><\/code><code><span class=\"code-snippet_outer\">        Map map = new HashMap();<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;map.put(\"aaa\",&nbsp;o);&nbsp;\/\/\u5c06\"aaa\"\u548c&nbsp;Object\u5b9e\u4f8b\u6620\u5c04\u5e76\u5173\u8054<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Student&nbsp;target&nbsp;=&nbsp;map.get(\"aaa\");&nbsp;\/\/\u901a\u8fc7key\u67e5\u627e\u5e76\u8fd4\u56de\u6620\u5c04\u7684Obj\u5b9e\u4f8b<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(target&nbsp;==&nbsp;o);&nbsp;\/\/true\uff0c\u540c\u4e00\u4e2a\u5b9e\u4f8b<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Student&nbsp;another&nbsp;=&nbsp;map.get(\"bbb\");&nbsp;\/\/\u901a\u8fc7\u53e6\u4e00\u4e2akey\u67e5\u627e<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;System.out.println(another);&nbsp;\/\/\u672a\u627e\u5230\u5219\u8fd4\u56denull<\/span><\/code><code><span class=\"code-snippet_outer\">    }<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/pre>\n<p>\u5728 Java \u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u4f7f\u7528\u5230\u4e00\u4e9b\u5904\u7406\u7f13\u5b58\u6570\u636e\u7684\u96c6\u5408\u7c7b\uff0c\u8fd9\u4e9b\u96c6\u5408\u7c7b\u90fd\u6709\u81ea\u5df1\u7684\u7279\u70b9\uff0c\u4eca\u5929\u4e3b\u8981\u5206\u4eab\u4e0b Java \u96c6\u5408\u4e2d\u51e0\u79cd\u7ecf\u5e38\u7528\u7684 Map\u3001List\u3001Set\u3002<\/p>\n<h2 id=\"\">\u76ee\u5f55<\/h2>\n<ol>\n<li><a href=\"#1-map\">Map<\/a><\/li>\n<\/ol>\n<ul>\n<li>\u80cc\u666f<\/li>\n<li>Map\u5bb6\u65cf<\/li>\n<li>HashMap\u3001Hashtable\u7b49<\/li>\n<li>HashMap \u5e95\u5c42\u6570\u636e\u7ed3\u6784<\/li>\n<\/ul>\n<ol>\n<li><a href=\"#2-list\">List<\/a><\/li>\n<\/ol>\n<ul>\n<li>List\u5305\u62ec\u7684\u5b50\u7c7b<\/li>\n<li>ArrayList<\/li>\n<li>ArrayList\u6e90\u7801\u5206\u6790<\/li>\n<li>LinkedList<\/li>\n<li>LinkedList\u6e90\u7801\u5206\u6790<\/li>\n<\/ul>\n<ol>\n<li><a href=\"#3-set\">Set<\/a><\/li>\n<\/ol>\n<ul>\n<li>Set\u7684\u5b9e\u8d28<\/li>\n<li>HashSet<\/li>\n<li>TreeSet<\/li>\n<\/ul>\n<h2 id=\"011map\">01 \u96c6\u5408 1\uff1aMap<\/h2>\n<h3 id=\"-1\">\u80cc\u666f<\/h3>\n<p>\u5982\u679c\u4e00\u4e2a\u6d77\u91cf\u7684\u6570\u636e\u4e2d\uff0c\u9700\u8981\u67e5\u8be2\u67d0\u4e2a\u6307\u5b9a\u7684\u4fe1\u606f\uff0c\u8fd9\u65f6\u5019\uff0c\u53ef\u80fd\u4f1a\u72b9\u5982\u5927\u6d77\u635e\u9488\uff0c\u8fd9\u65f6\u5019\uff0c\u53ef\u4ee5\u4f7f\u7528 Map \u6765\u8fdb\u884c\u4e00\u4e2a\u83b7\u53d6\u3002\u56e0\u4e3a Map \u662f\u952e\u503c\u5bf9\u96c6\u5408\u3002Map\u8fd9\u79cd\u952e\u503c\uff08key-value\uff09\u6620\u5c04\u8868\u7684\u6570\u636e\u7ed3\u6784\uff0c\u4f5c\u7528\u5c31\u662f\u901a\u8fc7key\u80fd\u591f\u9ad8\u6548\u3001\u5feb\u901f\u67e5\u627evalue\u3002<\/p>\n<p>\u4e3e\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"cpp\"><code><span class=\"code-snippet_outer\">import java.util.HashMap;<\/span><\/code><code><span class=\"code-snippet_outer\">import java.util.Map;<\/span><\/code><code><span class=\"code-snippet_outer\">public class Test {<\/span><\/code><code><span class=\"code-snippet_outer\">    public static void main(String[] args) {<\/span><\/code><code><span class=\"code-snippet_outer\">        Map map = new HashMap();<\/span><\/code><code><span class=\"code-snippet_outer\">        map.put(\"dog\", \"a\");<\/span><\/code><code><span class=\"code-snippet_outer\">        map.put(\"pig\", \"b\");<\/span><\/code><code><span class=\"code-snippet_outer\">        map.put(\"cat\", \"c\");<\/span><\/code><code><span class=\"code-snippet_outer\">        for (Map.Entry entry : map.entrySet()) {<\/span><\/code><code><span class=\"code-snippet_outer\">            String key = entry.getKey();<\/span><\/code><code><span class=\"code-snippet_outer\">            Integer value = entry.getValue();<\/span><\/code><code><span class=\"code-snippet_outer\">            System.out.println(key + \" = \" + value);<\/span><\/code><code><span class=\"code-snippet_outer\">        }<\/span><\/code><code><span class=\"code-snippet_outer\">    }<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">\/\/print<\/span><\/code><code><span class=\"code-snippet_outer\">cat&nbsp;=&nbsp;c<\/span><\/code><code><span class=\"code-snippet_outer\">dog&nbsp;=&nbsp;a<\/span><\/code><code><span class=\"code-snippet_outer\">pig&nbsp;=&nbsp;b<\/span><\/code><\/pre>\n<p>Map\u662f\u4e00\u79cd\u952e-\u503c\u6620\u5c04\u8868\uff0c\u5f53\u6211\u4eec\u8c03\u7528put(K key, V value)\u65b9\u6cd5\u65f6\uff0c\u5c31\u628akey\u548cvalue\u505a\u4e86\u6620\u5c04\u5e76\u653e\u5165Map\u3002\u5f53\u6211\u4eec\u8c03\u7528V get(K key)\u65f6\uff0c\u5c31\u53ef\u4ee5\u901a\u8fc7key\u83b7\u53d6\u5230\u5bf9\u5e94\u7684value\u3002\u5982\u679ckey\u4e0d\u5b58\u5728\uff0c\u5219\u8fd4\u56denull\u3002\u548cList\u7c7b\u4f3c\uff0cMap\u4e5f\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u6700\u5e38\u7528\u7684\u5b9e\u73b0\u7c7b\u662fHashMap\u3002<\/p>\n<p>\u5728 Map \u4e2d\uff0c\u5982\u679c\u904d\u5386\u7684\u65f6\u5019\uff0c\u5176 key \u662f\u65e0\u5e8f\u7684\uff0c\u5982\u4f55\u7406\u89e3\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/s1sql1tew.hb-bkt.clouddn.com\/photos\/20231019\/1ea30924c2d450df943ffe70a2875464_1.jpg\" alt=\"hashcat\u6e90\u4ee3\u7801\u89e3\u6790\"><\/p>\n<pre class=\"code-snippet__js\" data-lang=\"java\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__class\"><span class=\"code-snippet__keyword\">class<\/span> <span class=\"code-snippet__title\">HashMap<\/span>&lt;<span class=\"code-snippet__title\">K<\/span>,<span class=\"code-snippet__title\">V<\/span>&gt; <span class=\"code-snippet__keyword\">extends<\/span> <span class=\"code-snippet__title\">AbstractMap<\/span>&lt;<span class=\"code-snippet__title\">K<\/span>,<span class=\"code-snippet__title\">V<\/span>&gt;<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet_outer\">    <span class=\"code-snippet__keyword\">implements<\/span> <span class=\"code-snippet__title\">Map<\/span>&lt;<span class=\"code-snippet__title\">K<\/span>,<span class=\"code-snippet__title\">V<\/span>&gt;, <span class=\"code-snippet__title\">Cloneable<\/span>, <span class=\"code-snippet__title\">Serializable<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;<span class=\"code-snippet__keyword\">private<\/span>&nbsp;<span class=\"code-snippet__keyword\">static<\/span>&nbsp;<span class=\"code-snippet__keyword\">final<\/span>&nbsp;<span class=\"code-snippet__keyword\">long<\/span>&nbsp;serialVersionUID&nbsp;=&nbsp;<span class=\"code-snippet__number\">362498820763181265L<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;<span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      * \u9ed8\u8ba4\u5927\u5c0f 16<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=\"code-snippet__keyword\">static<\/span>&nbsp;<span class=\"code-snippet__keyword\">final<\/span>&nbsp;<span class=\"code-snippet__keyword\">int<\/span>&nbsp;DEFAULT_INITIAL_CAPACITY&nbsp;=&nbsp;<span class=\"code-snippet__number\">1<\/span>&nbsp;&lt;&lt;&nbsp;<span class=\"code-snippet__number\">4<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">      <\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;\u6700\u5927\u5bb9\u91cf\u662f\u5fc5\u987b\u662f2\u7684\u5e4230<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">static<\/span> <span class=\"code-snippet__keyword\">final<\/span> <span class=\"code-snippet__keyword\">int<\/span> MAXIMUM_CAPACITY = <span class=\"code-snippet__number\">1<\/span> &lt;&lt; <span class=\"code-snippet__number\">30<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">      <\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;\u8d1f\u8f7d\u56e0\u5b50\u9ed8\u8ba4\u4e3a0.75\uff0chashmap\u6bcf\u6b21\u6269\u5bb9\u4e3a\u539fhashmap\u76842\u500d<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">static<\/span> <span class=\"code-snippet__keyword\">final<\/span> <span class=\"code-snippet__keyword\">float<\/span> DEFAULT_LOAD_FACTOR = <span class=\"code-snippet__number\">0.75f<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">      <\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      * \u94fe\u8868\u7684\u6700\u5927\u957f\u5ea6\u4e3a8\uff0c\u5f53\u8d85\u8fc78\u65f6\u4f1a\u5c06\u94fe\u8868\u88c5\u6362\u4e3a\u7ea2\u9ed1\u6811\u8fdb\u884c\u5b58\u50a8<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">      *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=\"code-snippet__keyword\">static<\/span>&nbsp;<span class=\"code-snippet__keyword\">final<\/span>&nbsp;<span class=\"code-snippet__keyword\">int<\/span>&nbsp;TREEIFY_THRESHOLD&nbsp;=&nbsp;<span class=\"code-snippet__number\">8<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">       * The table, initialized on first use, and resized as<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">       * necessary. When allocated, length is always a power of two.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">       * (We also tolerate length zero in some operations to allow<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">       * bootstrapping mechanics that are currently not needed.)<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">       *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">transient<\/span> Node[] table;<\/span><\/code><code><span class=\"code-snippet_outer\">      <\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">static<\/span> <span class=\"code-snippet__class\"><span class=\"code-snippet__keyword\">class<\/span> <span class=\"code-snippet__title\">Node<\/span>&lt;<span class=\"code-snippet__title\">K<\/span>,<span class=\"code-snippet__title\">V<\/span>&gt; <span class=\"code-snippet__keyword\">implements<\/span> <span class=\"code-snippet__title\">Map<\/span>.<span class=\"code-snippet__title\">Entry<\/span>&lt;<span class=\"code-snippet__title\">K<\/span>,<span class=\"code-snippet__title\">V<\/span>&gt; <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__keyword\">final<\/span> <span class=\"code-snippet__keyword\">int<\/span> hash;<\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__keyword\">final<\/span> K key;<\/span><\/code><code><span class=\"code-snippet_outer\">        V value;<\/span><\/code><code><span class=\"code-snippet_outer\">        Node next;<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">        Node(<span class=\"code-snippet__keyword\">int<\/span> hash, K key, V value, Node next) {<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">this<\/span>.hash = hash;<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">this<\/span>.key = key;<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">this<\/span>.value = value;<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">this<\/span>.next = next;<\/span><\/code><code><span class=\"code-snippet_outer\">        }<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> K <span class=\"code-snippet__title\">getKey<\/span><span class=\"code-snippet__params\">()<\/span>        <\/span>{ <span class=\"code-snippet__keyword\">return<\/span> key; }<\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> V <span class=\"code-snippet__title\">getValue<\/span><span class=\"code-snippet__params\">()<\/span>      <\/span>{ <span class=\"code-snippet__keyword\">return<\/span> value; }<\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> String <span class=\"code-snippet__title\">toString<\/span><span class=\"code-snippet__params\">()<\/span> <\/span>{ <span class=\"code-snippet__keyword\">return<\/span> key + <span class=\"code-snippet__string\">\"=\"<\/span> + value; }<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> <span class=\"code-snippet__keyword\">int<\/span> <span class=\"code-snippet__title\">hashCode<\/span><span class=\"code-snippet__params\">()<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">return<\/span> Objects.hashCode(key) ^ Objects.hashCode(value);<\/span><\/code><code><span class=\"code-snippet_outer\">        }<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> V <span class=\"code-snippet__title\">setValue<\/span><span class=\"code-snippet__params\">(V newValue)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">            V oldValue = value;<\/span><\/code><code><span class=\"code-snippet_outer\">            value = newValue;<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">return<\/span> oldValue;<\/span><\/code><code><span class=\"code-snippet_outer\">        }<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">        <span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">final<\/span> <span class=\"code-snippet__keyword\">boolean<\/span> <span class=\"code-snippet__title\">equals<\/span><span class=\"code-snippet__params\">(Object o)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">if<\/span> (o == <span class=\"code-snippet__keyword\">this<\/span>)<\/span><\/code><code><span class=\"code-snippet_outer\">                <span class=\"code-snippet__keyword\">return<\/span> <span class=\"code-snippet__keyword\">true<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">if<\/span> (o <span class=\"code-snippet__keyword\">instanceof<\/span> Map.Entry) {<\/span><\/code><code><span class=\"code-snippet_outer\">                Map.Entry e = (Map.Entry)o;<\/span><\/code><code><span class=\"code-snippet_outer\">                <span class=\"code-snippet__keyword\">if<\/span> (Objects.equals(key, e.getKey()) &amp;&amp;<\/span><\/code><code><span class=\"code-snippet_outer\">                    Objects.equals(value, e.getValue()))<\/span><\/code><code><span class=\"code-snippet_outer\">                    <span class=\"code-snippet__keyword\">return<\/span> <span class=\"code-snippet__keyword\">true<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">            }<\/span><\/code><code><span class=\"code-snippet_outer\">            <span class=\"code-snippet__keyword\">return<\/span> <span class=\"code-snippet__keyword\">false<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">        }<\/span><\/code><code><span class=\"code-snippet_outer\">    }<\/span><\/code><\/pre>\n<p>\u4ece\u4e0a\u9762\u7684\u6253\u5370\u7ed3\u679c\u6765\u770b\uff0c\u5176\u662f\u65e0\u5e8f\u7684\uff0c\u6709\u5e8f\u7684\u7b54\u6848\u53ef\u4ee5\u5728\u4e0b\u9762\u627e\u5230\u3002<\/p>\n<p>\u63a5\u4e0b\u6765\u6211\u4eec\u5206\u6790\u4e0b Map \uff0c\u9996\u5148\u6211\u4eec\u5148\u770b\u770b Map \u5bb6\u65cf\uff1a<\/p>\n<p>\u5b83\u7684\u5b50\u5b59\u4e0b\u9762\u6709\u6211\u4eec\u5e38\u7528\u7684 HashMap\u3001LinkedHashMap\uff0c\u4e5f\u6709 TreeMap\uff0c\u53e6\u5916\u8fd8\u6709\u7ee7\u627f Dictionary\u3001\u5b9e\u73b0 Map \u63a5\u53e3\u7684 Hashtable\u3002<\/p>\n<p>\u4e0b\u9762\u9488\u5bf9\u5404\u4e2a\u5b9e\u73b0\u7c7b\u7684\u7279\u70b9\u6765\u8bf4\u660e\uff1a<\/p>\n<p>\uff081\uff09HashMap\uff1a\u5b83\u6839\u636e\u952e\u7684 hashCode \u503c\u5b58\u50a8\u6570\u636e\uff0c\u5927\u591a\u6570\u60c5\u51b5\u4e0b\u53ef\u4ee5\u76f4\u63a5\u5b9a\u4f4d\u5230\u5b83\u7684\u503c\uff0c\u56e0\u800c\u5177\u6709\u9ad8\u6548\u7684\u8bbf\u95ee\u901f\u5ea6\uff0c\u4f46\u904d\u5386\u987a\u5e8f\u5374\u662f\u4e0d\u786e\u5b9a\u7684\u3002HashMap\u6700\u591a\u53ea\u5141\u8bb8\u4e00\u6761\u8bb0\u5f55\u7684\u952e\u4e3anull\uff0c\u5141\u8bb8\u591a\u6761\u8bb0\u5f55\u7684\u503c\u4e3anull\u3002HashMap \u975e\u7ebf\u7a0b\u5b89\u5168\uff0c\u5373\u4efb\u4e00\u65f6\u523b\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u5199HashMap\uff0c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6570\u636e\u7684\u4e0d\u4e00\u81f4\u3002\u5982\u679c\u9700\u8981\u6ee1\u8db3\u7ebf\u7a0b\u5b89\u5168\uff0c\u53ef\u4ee5\u7528 Collections \u7684\u9759\u6001\u65b9\u6cd5 synchronizedMap \u65b9\u6cd5\u4f7f HashMap \u5177\u6709\u7ebf\u7a0b\u5b89\u5168\u7684\u80fd\u529b\uff0c\u6216\u8005\u4f7f\u7528 ConcurrentHashMap(\u5206\u6bb5\u52a0\u9501)\u3002<\/p>\n<p>\uff082\uff09LinkedHashMap\uff1aLinkedHashMap \u662f HashMap \u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u66ff HashMap \u5b8c\u6210\u4e86\u8f93\u5165\u987a\u5e8f\u7684\u8bb0\u5f55\u529f\u80fd\uff0c\u6240\u4ee5\u8981\u60f3\u5b9e\u73b0\u50cf\u8f93\u51fa\u540c\u8f93\u5165\u987a\u5e8f\u4e00\u81f4\uff0c\u5e94\u8be5\u4f7f\u7528 LinkedHashMap\u3002<\/p>\n<p>\uff083\uff09TreeMap\uff1aTreeMap \u5b9e\u73b0 SortedMap \u63a5\u53e3\uff0c\u80fd\u591f\u628a\u5b83\u4fdd\u5b58\u7684\u8bb0\u5f55\u6839\u636e\u952e\u6392\u5e8f\uff0c\u9ed8\u8ba4\u662f\u6309\u952e\u503c\u7684\u5347\u5e8f\u6392\u5e8f\uff0c\u4e5f\u53ef\u4ee5\u6307\u5b9a\u6392\u5e8f\u7684\u6bd4\u8f83\u5668\uff0c\u5f53\u7528 Iterator \u904d\u5386 TreeMap \u65f6\uff0c\u5f97\u5230\u7684\u8bb0\u5f55\u662f\u6392\u8fc7\u5e8f\u7684\u3002\u5982\u679c\u4f7f\u7528\u6392\u5e8f\u7684\u6620\u5c04\uff0c\u5efa\u8bae\u4f7f\u7528TreeMap\u3002\u5728\u4f7f\u7528 TreeMap \u65f6\uff0ckey \u5fc5\u987b\u5b9e\u73b0Comparable \u63a5\u53e3\u6216\u8005\u5728\u6784\u9020 TreeMap \u4f20\u5165\u81ea\u5b9a\u4e49\u7684 Comparator\uff0c\u5426\u5219\u4f1a\u5728\u8fd0\u884c\u65f6\u629b\u51fa ClassCastException \u7c7b\u578b\u7684\u5f02\u5e38\u3002<\/p>\n<p>\uff084\uff09Hashtable\uff1aHashtable\u7ee7\u627f Dictionary \u7c7b\uff0c\u5b9e\u73b0 Map \u63a5\u53e3\uff0c\u5f88\u591a\u6620\u5c04\u7684\u5e38\u7528\u529f\u80fd\u4e0e HashMap \u7c7b\u4f3c\uff0cHashtable \u91c7\u7528&#8221;\u62c9\u94fe\u6cd5&#8221;\u5b9e\u73b0\u54c8\u5e0c\u8868\uff0c\u4e0d\u540c\u7684\u662f\u5b83\u6765\u81ea Dictionary \u7c7b\uff0c\u5e76\u4e14\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u4efb\u4e00\u65f6\u95f4\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u5199 Hashtable\uff0c\u4f46\u5e76\u53d1\u6027\u4e0d\u5982 ConcurrentHashMap\uff0c\u56e0\u4e3aConcurrentHashMap \u5f15\u5165\u4e86\u5206\u6bb5\u9501\u3002Hashtable \u4f7f\u7528 synchronized \u6765\u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168\uff0c\u5728\u7ebf\u7a0b\u7ade\u4e89\u6fc0\u70c8\u7684\u60c5\u51b5\u4e0b HashTable \u7684\u6548\u7387\u975e\u5e38\u4f4e\u4e0b\u3002\u4e0d\u5efa\u8bae\u5728\u65b0\u4ee3\u7801\u4e2d\u4f7f\u7528\uff0c\u4e0d\u9700\u8981\u7ebf\u7a0b\u5b89\u5168\u7684\u573a\u5408\u53ef\u4ee5\u7528 HashMap \u66ff\u6362\uff0c\u9700\u8981\u7ebf\u7a0b\u5b89\u5168\u7684\u573a\u5408\u53ef\u4ee5\u7528 ConcurrentHashMap \u66ff\u6362\u3002Hashtable \u5e76\u4e0d\u662f\u50cf ConcurrentHashMap \u5bf9\u6570\u7ec4\u7684\u6bcf\u4e2a\u4f4d\u7f6e\u52a0\u9501\uff0c\u800c\u662f\u5bf9\u64cd\u4f5c\u52a0\u9501\uff0c\u6027\u80fd\u8f83\u5dee\u3002<\/p>\n<p>\u4e0a\u9762\u8bb2\u5230\u4e86 HashMap\u3001Hashtable\u3001ConcurrentHashMap\uff0c\u63a5\u4e0b\u6765\u5148\u770b\u770b HashMap \u7684\u6e90\u7801\u5b9e\u73b0\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"javascript\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">else<\/span> <span class=\"code-snippet__keyword\">if<\/span> ((newCap = oldCap &lt;&lt; <span class=\"code-snippet__number\">1<\/span>) &lt; MAXIMUM_CAPACITY &amp;&amp;<\/span><\/code><code><span class=\"code-snippet_outer\">                     oldCap &gt;= DEFAULT_INITIAL_CAPACITY)<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;newThr&nbsp;=&nbsp;oldThr&nbsp;&lt;&lt;&nbsp;<span class=\"code-snippet__number\">1<\/span>;<\/span><\/code><\/pre>\n<p>\u4ece\u4e0a\u9762\u770b\u5230\uff0cHashMap \u4e3b\u8981\u662f\u6570\u7ec4 +\u94fe\u8868\u7ed3\u6784\u7ec4\u6210\u3002HashMap \u6269\u5bb9\u662f\u6210\u500d\u7684\u6269\u5bb9\u3002\u4e3a\u4ec0\u4e48\u662f\u6210\u500d\uff0c\u800c\u4e0d\u662f1.5\u6216\u5176\u4ed6\u7684\u500d\u6570\u5462\uff1f\u65e2\u7136 HashMap \u5728\u8fdb\u884c put \u7684\u65f6\u5019\u9488\u5bf9 key \u505a\u4e86\u4e00\u4e9b\u5217\u7684 hash \u4ee5\u53ca\u4e0e\u8fd0\u7b97\u5c31\u662f\u4e3a\u4e86\u51cf\u5c11\u78b0\u649e\u7684\u4e00\u4e2a\u6982\u7387\uff0c\u5982\u679c\u6269\u5bb9\u540e\u7684\u5927\u5c0f\u4e0d\u662f2\u7684n\u6b21\u5e42\u7684\u8bdd\uff0c\u4e4b\u524d\u505a\u7684\u4e0d\u662f\u767d\u8d39\u4e86\u5417\uff1f<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/s1sql1tew.hb-bkt.clouddn.com\/photos\/20231019\/1ea30924c2d450df943ffe70a2875464_2.png\" alt=\"hashcat\u6e90\u4ee3\u7801\u89e3\u6790\"><\/p>\n<p>\u6269\u5bb9\u540e\u4f1a\u91cd\u65b0\u628a\u539f\u6765\u7684\u6240\u6709\u7684\u6570\u636e key \u7684 hash \u91cd\u65b0\u8ba1\u7b97\u653e\u5165\u6269\u5bb9\u540e\u7684\u6570\u7ec4\u91cc\u9762\u53bb\u3002\u4e3a\u4ec0\u4e48\u8981\u8fd9\u6837\u505a\uff1f\u56e0\u4e3a\u4e0d\u540c\u7684\u6570\u7ec4\u5927\u5c0f\u901a\u8fc7 key \u7684 hash \u51fa\u6765\u7684\u4e0b\u6807\u662f\u4e0d\u4e00\u6837\u7684\u3002\u8fd8\u6709\uff0c\u6570\u7ec4\u957f\u5ea6\u4fdd\u63012\u7684\u6b21\u5e42\uff0clength-1\u7684\u4f4e\u4f4d\u90fd\u4e3a1\uff0c\u4f1a\u4f7f\u5f97\u83b7\u5f97\u7684\u6570\u7ec4\u7d22\u5f15index\u66f4\u52a0\u5747\u5300\u3002<\/p>\n<p>\u4e3a\u4f55\u8bf4 Hashmap \u662f\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\u5462\uff1f\u539f\u56e0\uff1a\u5f53\u591a\u7ebf\u7a0b\u5e76\u53d1\u65f6\uff0c\u68c0\u6d4b\u5230\u603b\u6570\u91cf\u8d85\u8fc7\u95e8\u9650\u503c\u7684\u65f6\u5019\u5c31\u4f1a\u540c\u65f6\u8c03\u7528 resize \u64cd\u4f5c\uff0c\u5404\u81ea\u751f\u6210\u65b0\u7684\u6570\u7ec4\u5e76rehash \u540e\u8d4b\u7ed9\u5e95\u5c42\u6570\u7ec4\uff0c\u7ed3\u679c\u6700\u7ec8\u53ea\u6709\u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u751f\u6210\u7684\u65b0\u6570\u7ec4\u88ab\u8d4b\u7ed9table \u53d8\u91cf\uff0c\u5176\u4ed6\u7ebf\u7a0b\u5747\u4f1a\u4e22\u5931\u3002\u800c\u4e14\u5f53\u67d0\u4e9b\u7ebf\u7a0b\u5df2\u7ecf\u5b8c\u6210\u8d4b\u503c\u800c\u5176\u4ed6\u7ebf\u7a0b\u521a\u5f00\u59cb\u7684\u65f6\u5019\uff0c\u5c31\u4f1a\u7528\u5df2\u7ecf\u88ab\u8d4b\u503c\u7684 table \u4f5c\u4e3a\u539f\u59cb\u6570\u7ec4\uff0c\u8fd9\u6837\u4e5f\u662f\u6709\u95ee\u9898\u6ef4\u3002<\/p>\n<p>\u7591\u95ee\uff1aHashMap \u4e2d\u67d0\u4e2a entry \u94fe\u8fc7\u957f\uff0c\u67e5\u8be2\u65f6\u95f4\u8fbe\u5230\u6700\u5927\u9650\u5ea6\uff0c\u5982\u4f55\u5904\u7406\u5462\uff1f\u8fd9\u4e2a\u5728 Jdk1.8\uff0c\u5f53\u94fe\u8868\u8fc7\u957f\uff0c\u628a\u94fe\u8868\u8f6c\u6210\u7ea2\u9ed1\u6811(TreeNode)\u5b9e\u73b0\u4e86\u66f4\u9ad8\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u7684\u67e5\u627e\u3002<\/p>\n<p>HashMap\u4e2d\u54c8\u5e0c\u7b97\u6cd5\u5b9e\u73b0\uff1f\u6211\u4eec\u4f7f\u7528put(key,value)\u65b9\u6cd5\u5f80HashMap\u4e2d\u6dfb\u52a0\u5143\u7d20\u65f6\uff0c\u5148\u8ba1\u7b97\u5f97\u5230key\u7684 Hash \u503c\uff0c\u7136\u540e\u901a\u8fc7Key\u9ad816\u4f4d\u4e0e\u4f4e16\u4f4d\u76f8\u5f02\u6216\uff08\u9ad816\u4f4d\u4e0d\u53d8\uff09\uff0c\u7136\u540e\u4e0e\u6570\u7ec4\u5927\u5c0f-1\u76f8\u4e0e\uff0c\u5f97\u5230\u4e86\u8be5\u5143\u7d20\u5728\u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\uff0c\u6d41\u7a0b\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/s1sql1tew.hb-bkt.clouddn.com\/photos\/20231019\/1ea30924c2d450df943ffe70a2875464_3.png\" alt=\"hashcat\u6e90\u4ee3\u7801\u89e3\u6790\"><\/p>\n<p>\u5ef6\u4f38\uff1a\u5982\u679c\u4e00\u4e2a\u5bf9\u8c61\u4e2d\uff0c\u91cd\u5199\u4e86equals()\u800c\u4e0d\u91cd\u5199hashcode()\u4f1a\u53d1\u751f\u4ec0\u4e48\u6837\u7684\u95ee\u9898\uff1f\u5c3d\u7ba1\u6211\u4eec\u5728\u8fdb\u884c get \u548c put \u64cd\u4f5c\u7684\u65f6\u5019\uff0c\u4f7f\u7528\u7684key\u4ece\u903b\u8f91\u4e0a\u8bb2\u662f\u7b49\u503c\u7684\uff08\u901a\u8fc7equals\u6bd4\u8f83\u662f\u76f8\u7b49\u7684\uff09\uff0c\u4f46\u7531\u4e8e\u6ca1\u6709\u91cd\u5199hashCode()\uff0c\u6240\u4ee5put\u64cd\u4f5c\u65f6\uff0ckey(hashcode1)&#8211;&gt;hash&#8211;&gt;indexFor&#8211;&gt;index\uff0c\u800c\u901a\u8fc7key\u53d6\u51favalue\u7684\u65f6\u5019 key(hashcode2)&#8211;&gt;hash&#8211;&gt;indexFor&#8211;&gt;index\uff0c\u7531\u4e8ehashcode1\u4e0d\u7b49\u4e8ehashcode2\uff0c\u5bfc\u81f4\u6ca1\u6709\u5b9a\u4f4d\u5230\u4e00\u4e2a\u6570\u7ec4\u4f4d\u7f6e\u800c\u8fd4\u56de\u903b\u8f91\u4e0a\u9519\u8bef\u7684\u503cnull\u3002\u6240\u4ee5\uff0c\u5728\u91cd\u5199equals()\u7684\u65f6\u5019\uff0c\u5fc5\u987b\u6ce8\u610f\u91cd\u5199hashCode()\uff0c\u540c\u65f6\u8fd8\u8981\u4fdd\u8bc1\u901a\u8fc7equals()\u5224\u65ad\u76f8\u7b49\u7684\u4e24\u4e2a\u5bf9\u8c61\uff0c\u8c03\u7528hashCode\u65b9\u6cd5\u8981\u8fd4\u56de\u540c\u6837\u7684\u6574\u6570\u503c\u3002\u800c\u5982\u679cequals\u5224\u65ad\u4e0d\u76f8\u7b49\u7684\u4e24\u4e2a\u5bf9\u8c61\uff0c\u5176hashCode\u4e5f\u53ef\u4ee5\u76f8\u540c\u7684\uff08\u53ea\u4e0d\u8fc7\u4f1a\u53d1\u751f\u54c8\u5e0c\u51b2\u7a81\uff0c\u5e94\u5c3d\u91cf\u907f\u514d\uff09\u3002\uff081.hash\u76f8\u540c\uff0c\u4f46key\u4e0d\u4e00\u5b9a\u76f8\u540c\uff1akey1\u3001key2\u4ea7\u751f\u7684hash\u5f88\u6709\u53ef\u80fd\u662f\u76f8\u540c\u7684\uff0c\u5982\u679ckey\u771f\u7684\u76f8\u540c\uff0c\u5c31\u4e0d\u4f1a\u5b58\u5728\u6563\u5217\u94fe\u8868\u4e86\uff0c\u6563\u5217\u94fe\u8868\u662f\u5f88\u591a\u4e0d\u540c\u7684\u952e\u7b97\u51fa\u7684hash\u503c\u548cindex\u76f8\u540c\u7684 2. key\u76f8\u540c\uff0c\u7ecf\u8fc7\u4e24\u6b21hash\uff0c\u5176hash\u503c\u4e00\u5b9a\u76f8\u540c\uff09<\/p>\n<p>ConcurrentHashMap\u91c7\u7528\u4e86\u5206\u6bb5\u9501\u6280\u672f\u6765\u5c06\u6570\u636e\u5206\u6210\u4e00\u6bb5\u6bb5\u7684\u5b58\u50a8\uff0c\u7136\u540e\u7ed9\u6bcf\u4e00\u6bb5\u6570\u636e\u914d\u4e00\u628a\u9501\uff0c\u5f53\u4e00\u4e2a\u7ebf\u7a0b\u5360\u7528\u9501\u8bbf\u95ee\u5176\u4e2d\u4e00\u4e2a\u6bb5\u6570\u636e\u7684\u65f6\u5019\uff0c\u5176\u4ed6\u6bb5\u7684\u6570\u636e\u4e5f\u80fd\u88ab\u5176\u4ed6\u7ebf\u7a0b\u8bbf\u95ee\u3002<\/p>\n<h2 id=\"022list\">02 \u96c6\u5408 2\uff1aList<\/h2>\n<p>\u96c6\u5408 List \u662f\u63a5\u53e3 Collection \u7684\u5b50\u63a5\u53e3\uff0c\u4e5f\u662f\u5927\u5bb6\u7ecf\u5e38\u7528\u5230\u7684\u6570\u636e\u7f13\u5b58\u3002List\u8fdb\u884c\u4e86\u5143\u7d20\u6392\u5e8f\uff0c\u4e14\u5141\u8bb8\u5b58\u653e\u76f8\u540c\u7684\u5143\u7d20\uff0c\u5373\u6709\u5e8f\uff0c\u53ef\u91cd\u590d\u3002\u6211\u4eec\u5148\u770b\u770b\u6709\u54ea\u4e9b\u5b50\u7c7b\uff1a<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/s1sql1tew.hb-bkt.clouddn.com\/photos\/20231019\/1ea30924c2d450df943ffe70a2875464_4.png\" alt=\"hashcat\u6e90\u4ee3\u7801\u89e3\u6790\"><\/p>\n<p>\u53ef\u4ee5\u770b\u5230\uff0c\u5176\u4e2d\u5305\u62ec\u6bd4\u8f83\u591a\u7684\u5b50\u7c7b\uff0c\u6211\u4eec\u5e38\u7528\u7684\u662f ArrayList\u3001LinkedList:<\/p>\n<p>ArrayList\uff1a<\/p>\n<p>\u4f18\u70b9\uff1a\u64cd\u4f5c\u8bfb\u53d6\u64cd\u4f5c\u6548\u7387\u9ad8\uff0c\u57fa\u4e8e\u6570\u7ec4\u5b9e\u73b0\u7684\uff0c\u53ef\u4ee5\u4e3anull\u503c\uff0c\u53ef\u4ee5\u5141\u8bb8\u91cd\u590d\u5143\u7d20\uff0c\u6709\u5e8f\uff0c\u5f02\u6b65\u3002<\/p>\n<p>\u7f3a\u70b9\uff1a\u7531\u4e8e\u5b83\u662f\u7531\u52a8\u6001\u6570\u7ec4\u5b9e\u73b0\u7684\uff0c\u4e0d\u9002\u5408\u9891\u7e41\u7684\u5bf9\u5143\u7d20\u7684\u63d2\u5165\u548c\u5220\u9664\u64cd\u4f5c\uff0c\u56e0\u4e3a\u6bcf\u6b21\u63d2\u5165\u548c\u5220\u9664\u90fd\u9700\u8981\u79fb\u52a8\u6570\u7ec4\u4e2d\u7684\u5143\u7d20\u3002<\/p>\n<p>LinkedList\uff1a<\/p>\n<p>\u4f18\u70b9\uff1aLinkedList\u7531\u53cc\u94fe\u8868\u5b9e\u73b0\uff0c\u589e\u5220\u7531\u4e8e\u4e0d\u9700\u8981\u79fb\u52a8\u5e95\u5c42\u6570\u7ec4\u6570\u636e\uff0c\u5176\u5e95\u5c42\u662f\u94fe\u8868\u5b9e\u73b0\u7684\uff0c\u53ea\u9700\u8981\u4fee\u6539\u94fe\u8868\u8282\u70b9\u6307\u9488\uff0c\u5bf9\u5143\u7d20\u7684\u63d2\u5165\u548c\u5220\u9664\u6548\u7387\u8f83\u9ad8\u3002<\/p>\n<p>\u7f3a\u70b9\uff1a\u904d\u5386\u6548\u7387\u8f83\u4f4e\u3002HashMap\u548c\u53cc\u94fe\u8868\u4e5f\u6709\u5173\u7cfb\u3002<\/p>\n<p>ArrayList \u5e95\u5c42\u662f\u4e00\u4e2a\u53d8\u957f\u7684\u6570\u7ec4\uff0c\u57fa\u672c\u4e0a\u7b49\u540c\u4e8eVector\uff0c\u4f46\u662fArrayList\u5bf9writeObjec() \u548c readObject()\u65b9\u6cd5\u5b9e\u73b0\u4e86\u540c\u6b65\u3002<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"php\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">If<\/span>&nbsp;multiple&nbsp;threads&nbsp;access&nbsp;an&nbsp;<tt>ArrayList<\/tt>&nbsp;instance&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\">concurrently,&nbsp;<span class=\"code-snippet__keyword\">and<\/span>&nbsp;at&nbsp;least&nbsp;one&nbsp;of&nbsp;the&nbsp;threads&nbsp;modifies&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\">the&nbsp;<span class=\"code-snippet__keyword\">list<\/span>&nbsp;structurally,&nbsp;it&nbsp;<i>must<\/i>&nbsp;be&nbsp;synchronized&nbsp;externally.<\/span><\/code><code><span class=\"code-snippet_outer\">(A&nbsp;structural&nbsp;modification&nbsp;is&nbsp;any&nbsp;operation&nbsp;that&nbsp;adds&nbsp;<span class=\"code-snippet__keyword\">or<\/span>&nbsp;deletes&nbsp;one&nbsp;<span class=\"code-snippet__keyword\">or<\/span>&nbsp;more&nbsp;elements,&nbsp;<span class=\"code-snippet__keyword\">or<\/span>&nbsp;explicitly&nbsp;resizes&nbsp;the&nbsp;backing&nbsp;<span class=\"code-snippet__keyword\">array<\/span>;&nbsp;merely&nbsp;setting&nbsp;the&nbsp;value&nbsp;of&nbsp;an&nbsp;element&nbsp;is&nbsp;not&nbsp;a&nbsp;structural&nbsp;modification.)<\/span><\/code><code><span class=\"code-snippet_outer\">This&nbsp;is&nbsp;typically&nbsp;accomplished&nbsp;by&nbsp;synchronizing&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\">on&nbsp;some&nbsp;object&nbsp;that&nbsp;naturally&nbsp;encapsulates&nbsp;the&nbsp;<span class=\"code-snippet__keyword\">list<\/span>.<\/span><\/code><\/pre>\n<p>\u4ece\u6ce8\u91ca\uff0c\u6211\u4eec\u77e5\u9053 ArrayList \u662f\u7ebf\u7a0b\u4e0d\u5b89\u5168\u7684\uff0c\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u8981\u901a\u8fc7\u5916\u90e8\u7684\u540c\u6b65\u7b56\u7565\u540e\u4f7f\u7528\uff0c\u6bd4\u5982List list = Collections.synchronizedList(new ArrayList(\u2026))\u3002<\/p>\n<p>\u6e90\u7801\u5b9e\u73b0\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"typescript\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**        <\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Default initial capacity.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> <span class=\"code-snippet__keyword\">static<\/span> final int DEFAULT_CAPACITY = <span class=\"code-snippet__number\">10<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\"> <\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Shared empty array instance used for empty instances.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> <span class=\"code-snippet__keyword\">static<\/span> final <span class=\"code-snippet__built_in\">Object<\/span>[] EMPTY_ELEMENTDATA = {};<\/span><\/code><code><span class=\"code-snippet_outer\"> <\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Shared empty array instance used for default sized empty instances. <\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> <span class=\"code-snippet__keyword\">static<\/span> final <span class=\"code-snippet__built_in\">Object<\/span>[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {};<\/span><\/code><code><span class=\"code-snippet_outer\"> <\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * The array buffer into which the elements of the ArrayList are stored.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">transient <span class=\"code-snippet__built_in\">Object<\/span>[] elementData; <span class=\"code-snippet__comment\">\/\/ non-private to simplify nested class access<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"> <\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * The size of the ArrayList (the number of elements it contains).<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> int size;<\/span><\/code><\/pre>\n<p>\u5f53\u8c03\u7528add\u51fd\u6570\u65f6\uff0c\u4f1a\u8c03\u7528ensureCapacityInternal\u51fd\u6570\u8fdb\u884c\u6269\u5bb9\uff0c\u6bcf\u6b21\u6269\u5bb9\u4e3a\u539f\u6765\u5927\u5c0f\u76841.5\u500d\uff0c\u4f46\u662f\u5f53\u7b2c\u4e00\u6b21\u6dfb\u52a0\u5143\u7d20\u6216\u8005\u5217\u8868\u4e2d\u5143\u7d20\u4e2a\u6570\u5c0f\u4e8e10\u7684\u8bdd\uff0c\u5217\u8868\u5bb9\u91cf\u9ed8\u8ba4\u4e3a10\u3002<\/p>\n<p>\u6269\u5bb9\u539f\u7406\uff1a\u6839\u636e\u5f53\u524d\u6570\u7ec4\u7684\u5927\u5c0f\uff0c\u5224\u65ad\u662f\u5426\u5c0f\u4e8e\u9ed8\u8ba4\u503c10\uff0c\u5982\u679c\u5927\u4e8e\uff0c\u5219\u9700\u8981\u6269\u5bb9\u81f3\u5f53\u524d\u6570\u7ec4\u5927\u5c0f\u76841.5\u500d\uff0c\u91cd\u65b0\u5c06\u65b0\u6269\u5bb9\u7684\u6570\u7ec4\u6570\u636ecopy\u53ea\u5f53\u524delementData\uff0c\u6700\u540e\u5c06\u4f20\u5165\u7684\u5143\u7d20\u8d4b\u503c\u7ed9size++\u4f4d\u7f6e\u3002<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"cs\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span>&nbsp;boolean&nbsp;<span class=\"code-snippet__title\">add<\/span>(<span class=\"code-snippet__params\">E&nbsp;e<\/span>)<\/span>&nbsp;{<\/span><\/code><code><span class=\"code-snippet_outer\">  ensureCapacityInternal(size + <span class=\"code-snippet__number\">1<\/span>);  <span class=\"code-snippet__comment\">\/\/ Increments modCount!!<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">  elementData[size++] = e;<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">return<\/span> <span class=\"code-snippet__literal\">true<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/pre>\n<p>\u63a5\u4e0b\u6765\u6211\u4eec\u5206\u6790\u4e3a\u4ec0\u4e48 ArrayList \u589e\u5220\u5f88\u6162\uff0c\u67e5\u8be2\u5f88\u5feb\u5462\uff1f<\/p>\n<p>\u6839\u636e\u6e90\u7801\u53ef\u77e5\uff0c\u5f53\u8c03\u7528add\u51fd\u6570\u65f6\uff0c\u9996\u5148\u8981\u8c03\u7528ensureCapacityInternal(size + 1)\uff0c\u8be5\u51fd\u6570\u662f\u8fdb\u884c\u81ea\u52a8\u6269\u5bb9\u7684\uff0c\u6548\u7387\u4f4e\u7684\u539f\u56e0\u4e5f\u5c31\u662f\u5728\u8fd9\u4e2a\u6269\u5bb9\u4e0a\u4e86\uff0c\u6bcf\u6b21\u65b0\u589e\u90fd\u8981\u5bf9\u73b0\u6709\u7684\u6570\u7ec4\u8fdb\u884c\u4e00\u6b211.5\u500d\u7684\u6269\u5927\uff0c\u6570\u7ec4\u95f4\u503c\u7684copy\u7b49\uff0c\u6700\u540e\u7b49\u6269\u5bb9\u5b8c\u6bd5\uff0c\u6709\u7a7a\u95f4\u4f4d\u7f6e\u4e86\uff0c\u5c06\u6570\u7ec4size+1\u7684\u4f4d\u7f6e\u653e\u5165\u5143\u7d20e\uff0c\u5b9e\u73b0\u65b0\u589e\u3002<\/p>\n<p>\u5220\u9664\u65f6\u6e90\u7801\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"java\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Returns the element at the specified position in this list.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@param<\/span>  index index of the element to return<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@return<\/span> the element at the specified position in this list<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@throws<\/span> IndexOutOfBoundsException {<span class=\"code-snippet__doctag\">@inheritDoc<\/span>}<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> E <span class=\"code-snippet__title\">get<\/span><span class=\"code-snippet__params\">(<span class=\"code-snippet__keyword\">int<\/span> index)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">  rangeCheck(index);<\/span><\/code><code><span class=\"code-snippet_outer\"> <\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">return<\/span> elementData(index);<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/pre>\n<p>\u5728\u5220\u9664index\u4f4d\u7f6e\u7684\u5143\u7d20\u65f6\uff0c\u8981\u5148\u8c03\u7528 rangeCheck(index) \u8fdb\u884c index \u7684check\uff0cindex \u8981\u8d85\u8fc7\u5f53\u524d\u4e2a\u6570\uff0c\u5219\u5224\u5b9a\u8d8a\u754c\uff0c\u629b\u51fa\u5f02\u5e38\uff0cthrow new IndexOutOfBoundsException(outOfBoundsMsg(index))\uff0c\u5176\u4ed6\u51fd\u6570\u4e5f\u6709\u7528\u5230\u5982\uff1aget(int index)\uff0cset(int index, E element) \u7b49\u540e\u9762\u5220\u9664\u91cd\u70b9\u5728\u4e8e\u8ba1\u7b97\u5220\u9664\u7684index\u662f\u672b\u5c3e\u8fd8\u662f\u4e2d\u95f4\u4f4d\u7f6e\uff0c\u672b\u5c3e\u76f4\u63a5&#8211;\uff0c\u7136\u540e\u7f6e\u7a7a\u5b8c\u4e8b\uff0c\u5982\u679c\u662f\u4e2d\u95f4\u4f4d\u7f6e\uff0c\u90a3\u5c31\u8981\u8fdb\u884c\u4e00\u4e2a\u6570\u7ec4\u95f4\u7684copy\uff0c\u91cd\u65b0\u7ec4\u5408\u6570\u7ec4\u6570\u636e\u4e86\uff0c\u8fd9\u4e00\u5c31\u6bd4\u8f83\u8017\u6027\u80fd\u4e86\u3002<\/p>\n<p>\u800c\u67e5\u8be2\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"makefile\"><code><span class=\"code-snippet_outer\">addFirst(E e):\u5c06\u6307\u5b9a\u5143\u7d20\u6dfb\u52a0\u5230\u5218\u8868\u5f00\u5934<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">addLast(E e):\u5c06\u6307\u5b9a\u5143\u7d20\u6dfb\u52a0\u5230\u5217\u8868\u672b\u5c3e<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">descendingIterator():\u4ee5\u9006\u5411\u987a\u5e8f\u8fd4\u56de\u5217\u8868\u7684\u8fed\u4ee3\u5668<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">element():\u83b7\u53d6\u4f46\u4e0d\u79fb\u9664\u5217\u8868\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">getFirst():\u8fd4\u56de\u5217\u8868\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">getLast():\u8fd4\u56de\u5217\u8868\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">offerFirst(E e):\u5728\u5217\u8868\u5f00\u5934\u63d2\u5165\u6307\u5b9a\u5143\u7d20<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">offerLast(E e):\u5728\u5217\u8868\u5c3e\u90e8\u63d2\u5165\u6307\u5b9a\u5143\u7d20<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">peekFirst():\u83b7\u53d6\u4f46\u4e0d\u79fb\u9664\u5217\u8868\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">peekLast():\u83b7\u53d6\u4f46\u4e0d\u79fb\u9664\u5217\u8868\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">pollFirst():\u83b7\u53d6\u5e76\u79fb\u9664\u5217\u8868\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">pollLast():\u83b7\u53d6\u5e76\u79fb\u9664\u5217\u8868\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">pop():\u4ece\u5217\u8868\u6240\u8868\u793a\u7684\u5806\u6808\u5f39\u51fa\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">push(E e);\u5c06\u5143\u7d20\u63a8\u5165\u5217\u8868\u8868\u793a\u7684\u5806\u6808<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">removeFirst():\u79fb\u9664\u5e76\u8fd4\u56de\u5217\u8868\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__section\">removeLast():\u79fb\u9664\u5e76\u8fd4\u56de\u5217\u8868\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">removeFirstOccurrence(E e):\u4ece\u5217\u8868\u4e2d\u79fb\u9664\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u6307\u5b9a\u5143\u7d20<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\">removeLastOccurrence(E e):\u4ece\u5217\u8868\u4e2d\u79fb\u9664\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u7684\u6307\u5b9a\u5143\u7d20<\/span><\/code><\/pre>\n<p>\u83b7\u53d6\u6307\u5b9aindex\u7684\u5143\u7d20\uff0c\u9996\u5148\u8c03\u7528rangeCheck(index)\u8fdb\u884cindex\u7684check\uff0c\u901a\u8fc7\u540e\u76f4\u63a5\u83b7\u53d6\u6570\u7ec4\u7684\u4e0b\u6807index\u83b7\u53d6\u6570\u636e\uff0c\u6ca1\u6709\u4efb\u4f55\u591a\u4f59\u64cd\u4f5c\uff0c\u9ad8\u6548\u3002<\/p>\n<p>LinkedList\u7ee7\u627fAbstractSequentialList\u548c\u5b9e\u73b0List\u63a5\u53e3\uff0c\u65b0\u589e\u63a5\u53e3\u5982\u4e0b\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"java\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/\/jdk 1.6<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> <span class=\"code-snippet__keyword\">transient<\/span> Entry header = <span class=\"code-snippet__keyword\">new<\/span> Entry(<span class=\"code-snippet__keyword\">null<\/span>, <span class=\"code-snippet__keyword\">null<\/span>, <span class=\"code-snippet__keyword\">null<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">private<\/span> <span class=\"code-snippet__keyword\">transient<\/span> <span class=\"code-snippet__keyword\">int<\/span> size = <span class=\"code-snippet__number\">0<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/\/jdk 1.7<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">transient<\/span> <span class=\"code-snippet__keyword\">int<\/span> size = <span class=\"code-snippet__number\">0<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">transient<\/span> Node first;<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;<\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__keyword\">transient<\/span> Node last;<\/span><\/code><\/pre>\n<p>LinkedList \u7684\u5b9e\u73b0\u539f\u7406\uff1aLinkedList \u7684\u5b9e\u73b0\u662f\u4e00\u4e2a\u53cc\u5411\u94fe\u8868\u3002\u5728 Jdk 1.6\u4e2d\u662f\u4e00\u4e2a\u5e26\u7a7a\u5934\u7684\u5faa\u73af\u53cc\u5411\u94fe\u8868\uff0c\u800c\u5728 Jdk1.7+ \u4e2d\u5219\u53d8\u4e3a\u4e0d\u5e26\u7a7a\u5934\u7684\u53cc\u5411\u94fe\u8868\uff0c\u8fd9\u4ece\u6e90\u7801\u4e2d\u53ef\u4ee5\u770b\u51fa\uff1a<\/p>\n<p>\u4ece\u6e90\u7801\u6ce8\u91ca\u770b\uff0cLinkedList\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u8981\u901a\u8fc7\u5916\u90e8\u7684\u540c\u6b65\u7b56\u7565\u540e\u4f7f\u7528\uff0c\u6bd4\u5982List list = Collections.synchronizedList(new LinkedList(\u2026))\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"java\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Appends the specified element to the end of this list.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <\/span><\/span><\/code><p><code>This method is equivalent to {<span class=\"code-snippet__doctag\">@link<\/span> #addLast}.<\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@param<\/span> e element to be appended to this list<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@return<\/span> {<span class=\"code-snippet__doctag\">@code<\/span> true} (as specified by {<span class=\"code-snippet__doctag\">@link<\/span> Collection#add})<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">boolean<\/span> <span class=\"code-snippet__title\">add<\/span><span class=\"code-snippet__params\">(E e)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">  linkLast(e);<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">return<\/span> <span class=\"code-snippet__keyword\">true<\/span>;<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Links e as last element.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">void<\/span> <span class=\"code-snippet__title\">linkLast<\/span><span class=\"code-snippet__params\">(E e)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">final<\/span> Node l = last;<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">final<\/span> Node newNode = <span class=\"code-snippet__keyword\">new<\/span> Node(l, e, <span class=\"code-snippet__keyword\">null<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\">  last = newNode;<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">if<\/span> (l == <span class=\"code-snippet__keyword\">null<\/span>)<\/span><\/code><code><span class=\"code-snippet_outer\">    first = newNode;<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">else<\/span><\/span><\/code><code><span class=\"code-snippet_outer\">    l.next = newNode;<\/span><\/code><code><span class=\"code-snippet_outer\">  size++;<\/span><\/code><code><span class=\"code-snippet_outer\">  modCount++;<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/p><\/pre>\n<p>\u4e3a\u4ec0\u4e48\u8bf4 LinkedList \u589e\u5220\u5f88\u5feb\u5462\uff1f<\/p>\n<p>\u4ece\u6ce8\u91ca\u770b\uff0cadd\u51fd\u6570\u5b9e\u5219\u662f\u5c06\u5143\u7d20append\u81f3list\u7684\u672b\u5c3e\uff0c\u5177\u4f53\u8fc7\u7a0b\u662f\uff1a\u65b0\u5efa\u4e00\u4e2aNode\u8282\u70b9\uff0c\u5176\u4e2d\u5c06\u540e\u9762\u7684\u90a3\u4e2a\u8282\u70b9last\u4f5c\u4e3a\u65b0\u8282\u70b9\u7684\u524d\u7f6e\u8282\u70b9\uff0c\u540e\u8282\u70b9\u4e3anull\uff1b\u5c06\u8fd9\u4e2a\u65b0Node\u8282\u70b9\u4f5c\u4e3a\u6574\u4e2alist\u7684\u540e\u8282\u70b9\uff0c\u5982\u679c\u4e4b\u524d\u7684\u540e\u8282\u70b9l\u4e3anull\uff0c\u5c06\u65b0\u5efa\u7684Node\u4f5c\u4e3alist\u7684\u524d\u8282\u70b9\uff0c\u5426\u5219\uff0clist\u7684\u540e\u8282\u70b9\u6307\u9488\u6307\u5411\u65b0\u5efaNode\uff0c\u6700\u540esize+1\uff0c\u5f53\u524dllist\u64cd\u4f5c\u6570modCount+1\u3002<\/p>\n<p>\u5728add\u4e00\u4e2a\u65b0\u5143\u7d20\u65f6\uff0cLinkedList \u6240\u5173\u5fc3\u7684\u91cd\u8981\u6570\u636e\uff0c\u4e00\u5171\u4e24\u4e2a\u53d8\u91cf\uff0c\u4e00\u4e2afirst\uff0c\u4e00\u4e2alast\uff0c\u8fd9\u5927\u5927\u63d0\u5347\u4e86\u63d2\u5165\u65f6\u7684\u6548\u7387\uff0c\u4e14\u9ed8\u8ba4\u662f\u8ffd\u52a0\u81f3\u672b\u5c3e\uff0c\u4fdd\u8bc1\u4e86\u987a\u5e8f\u3002<\/p>\n<p>\u518d\u770b\u5220\u9664\u4e00\u4e2a\u5143\u7d20\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"java\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/**<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * Returns the element at the specified position in this list.<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@param<\/span> index index of the element to return<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@return<\/span> the element at the specified position in this list<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> * <span class=\"code-snippet__doctag\">@throws<\/span> IndexOutOfBoundsException {<span class=\"code-snippet__doctag\">@inheritDoc<\/span>}<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\"> *\/<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> E <span class=\"code-snippet__title\">get<\/span><span class=\"code-snippet__params\">(<span class=\"code-snippet__keyword\">int<\/span> index)<\/span> <\/span>{<\/span><\/code><code><span class=\"code-snippet_outer\">  checkElementIndex(index);<\/span><\/code><code><span class=\"code-snippet_outer\">  <span class=\"code-snippet__keyword\">return<\/span> node(index).item;<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/pre>\n<p>\u5220\u9664\u6307\u5b9aindex\u7684\u5143\u7d20\uff0c\u5220\u9664\u4e4b\u524d\u8981\u8c03\u7528checkElementIndex(index)\u53bbcheck\u4e00\u4e0bindex\u662f\u5426\u5b58\u5728\u5143\u7d20\uff0c\u5982\u679c\u4e0d\u5b58\u5728\u629b\u51fathrow new IndexOutOfBoundsException(outOfBoundsMsg(index));\u8d8a\u754c\u9519\u8bef\uff0c\u540c\u6837\u8fd9\u4e2acheck\u65b9\u6cd5\u4e5f\u662f\u5f88\u591a\u65b9\u6cd5\u7528\u5230\u7684\uff0c\u5982\uff1aget(int index)\uff0cset(int index, E element)\u7b49\u3002<\/p>\n<p>\u6ce8\u91ca\u8bb2\uff0c\u5220\u9664\u7684\u662f\u975e\u7a7a\u7684\u8282\u70b9\uff0c\u8fd9\u91cc\u7684node\u8282\u70b9\u4e5f\u662f\u901a\u8fc7node(index)\u83b7\u53d6\u7684\uff0c\u5206\u522b\u6839\u636e\u5f53\u524dNode\u5f97\u5230\u94fe\u8868\u4e0a\u7684\u5173\u8282\u8981\u7d20\uff1aelement\u3001next\u3001prev\uff0c\u5206\u522b\u5bf9 prev \u548c next \u8fdb\u884c\u5224\u65ad\uff0c\u4ee5\u4fbf\u5bf9\u5f53\u524d list \u7684\u524d\u540e\u8282\u70b9\u8fdb\u884c\u91cd\u65b0\u8d4b\u503c\uff0cfrist\u548clast\uff0c\u6700\u540e\u5c06\u8282\u70b9\u7684element\u7f6e\u4e3anull\uff0c\u4e2a\u6570-1\uff0c\u64cd\u4f5c\u6570+1\u3002\u6839\u636e\u4ee5\u4e0a\u5206\u6790\uff0cremove\u8282\u70b9\u5173\u952e\u7684\u53d8\u91cf\uff0c\u662fNode\u5b9e\u4f8b\u672c\u8eab\u7684\u5c40\u90e8\u53d8\u91cf next\u3001prev\u3001item \u91cd\u65b0\u6784\u5efa\u5185\u90e8\u53d8\u91cf\u6307\u9488\u6307\u5411\uff0c\u4ee5\u53calist\u7684\u5c40\u90e8\u53d8\u91cffirst\u548clast\u4fdd\u8bc1\u8282\u70b9\u76f8\u8fde\u3002\u8fd9\u4e9b\u53d8\u91cf\u7684\u64cd\u4f5c\u4f7f\u5f97\u5176\u5220\u9664\u52a8\u4f5c\u4e5f\u5f88\u9ad8\u6548\u3002<\/p>\n<p>\u800c\u5bf9\u4e8e\u67e5\u8be2\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"cs\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__title\">HashSet<\/span>(<span class=\"code-snippet__params\"><\/span>)<\/span> {<\/span><\/code><code><span class=\"code-snippet_outer\">    map = <span class=\"code-snippet__keyword\">new<\/span> HashMap();<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><code><span class=\"code-snippet_outer\"><br><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__title\">TreeSet<\/span>(<span class=\"code-snippet__params\"><\/span>)<\/span> {<\/span><\/code><code><span class=\"code-snippet_outer\">    <span class=\"code-snippet__keyword\">this<\/span>(<span class=\"code-snippet__keyword\">new<\/span> TreeMap());<\/span><\/code><code><span class=\"code-snippet_outer\">}<\/span><\/code><\/pre>\n<p>\u83b7\u53d6\u6307\u5b9aindex\u4f4d\u7f6e\u7684node\uff0c\u83b7\u53d6\u4e4b\u524d\u8fd8\u662f\u8c03\u7528checkElementIndex(index)\u8fdb\u884c\u68c0\u67e5\u5143\u7d20\uff0c\u4e4b\u540e\u901a\u8fc7node(index)\u83b7\u53d6\u5143\u7d20\uff0c\u4e0a\u6587\u6709\u63d0\u5230\uff0cnode\u7684\u83b7\u53d6\u662f\u904d\u5386\u5f97\u5230\u7684\u5143\u7d20\uff0c\u6240\u4ee5\u76f8\u5bf9\u6027\u80fd\u6548\u7387\u4f1a\u4f4e\u4e00\u4e9b\u3002<\/p>\n<h2 id=\"033set\">03 \u96c6\u5408 3\uff1aSet<\/h2>\n<p>Set \u96c6\u5408\u5728\u6211\u4eec\u65e5\u5e38\u4e2d\uff0c\u7528\u5230\u7684\u4e5f\u6bd4\u8f83\u591a\u3002\u7528\u4e8e\u5b58\u50a8\u4e0d\u91cd\u590d\u7684\u5143\u7d20\u96c6\u5408\uff0c\u5b83\u4e3b\u8981\u63d0\u4f9b\u4e0b\u9762\u51e0\u79cd\u65b9\u6cd5\uff1a<\/p>\n<p>\u8fd9\u51e0\u79cd\u65b9\u6cd5\u8fd4\u56de\u7ed3\u679c\u90fd\u662f boolean\u503c\uff0c\u5373\u8fd4\u56de\u662f\u5426\u6b63\u786e\u6216\u6210\u529f\u3002Set \u76f8\u5f53\u4e8e\u53ea\u5b58\u50a8key\u3001\u4e0d\u5b58\u50a8value\u7684Map\u3002\u6211\u4eec\u7ecf\u5e38\u7528 Set \u7528\u4e8e\u53bb\u9664\u91cd\u590d\u5143\u7d20\uff0c\u56e0\u4e3a\u91cd\u590dadd\u540c\u4e00\u4e2a key \u65f6\uff0c\u4f1a\u8fd4\u56de false\u3002<\/p>\n<p>Set \u5b50\u5b59\u4e2d\u4e3b\u8981\u6709\uff1aHashSet\u3001SortedSet\u3002HashSet\u662f\u65e0\u5e8f\u7684\uff0c\u56e0\u4e3a\u5b83\u5b9e\u73b0\u4e86Set\u63a5\u53e3\uff0c\u5e76\u6ca1\u6709\u5b9e\u73b0SortedSet\u63a5\u53e3\uff0c\u800cTreeSet\u5b9e\u73b0\u4e86SortedSet\u63a5\u53e3\uff0c\u4ece\u800c\u4fdd\u8bc1\u5143\u7d20\u662f\u6709\u5e8f\u7684\u3002<\/p>\n<p>HashSet \u6dfb\u52a0\u540e\u8f93\u51fa\u4e5f\u662f\u65e0\u5e8f\u7684\uff1a<\/p>\n<pre class=\"code-snippet__js\" data-lang=\"cs\"><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__function\"><span class=\"code-snippet__keyword\">public<\/span> <span class=\"code-snippet__keyword\">static<\/span> <span class=\"code-snippet__keyword\">void<\/span> <span class=\"code-snippet__title\">main<\/span>(<span class=\"code-snippet__params\">String[] args<\/span>)<\/span> {<\/span><\/code><code><span class=\"code-snippet_outer\">  Set <span class=\"code-snippet__keyword\">set<\/span> = <span class=\"code-snippet__keyword\">new<\/span> TreeSet();<\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">set<\/span>.<span class=\"code-snippet__keyword\">add<\/span>(<span class=\"code-snippet__string\">\"2\"<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">set<\/span>.<span class=\"code-snippet__keyword\">add<\/span>(<span class=\"code-snippet__string\">\"6\"<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">set<\/span>.<span class=\"code-snippet__keyword\">add<\/span>(<span class=\"code-snippet__string\">\"44\"<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">set<\/span>.<span class=\"code-snippet__keyword\">add<\/span>(<span class=\"code-snippet__string\">\"5\"<\/span>);<\/span><\/code><code><span class=\"code-snippet_outer\">      <span class=\"code-snippet__keyword\">for<\/span> (String s : <span class=\"code-snippet__keyword\">set<\/span>) {<\/span><\/code><code><span class=\"code-snippet_outer\">          System.<span class=\"code-snippet__keyword\">out<\/span>.println(s);<\/span><\/code><code><span class=\"code-snippet_outer\">      }<\/span><\/code><code><span class=\"code-snippet_outer\">&nbsp;}<\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__comment\">\/\/print<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__number\">2<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__number\">44<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__number\">5<\/span><\/span><\/code><code><span class=\"code-snippet_outer\"><span class=\"code-snippet__number\">6<\/span><\/span><\/code><\/pre>\n<p><img decoding=\"async\" src=\"http:\/\/s1sql1tew.hb-bkt.clouddn.com\/photos\/20231019\/1ea30924c2d450df943ffe70a2875464_5.png\" alt=\"hashcat\u6e90\u4ee3\u7801\u89e3\u6790\"><\/p>\n<p>\u770b\u5230\u8f93\u51fa\u7684\u987a\u5e8f\u65e2\u4e0d\u662f\u6dfb\u52a0\u7684\u987a\u5e8f\uff0c\u4e5f\u4e0d\u662fString\u6392\u5e8f\u7684\u987a\u5e8f\uff0c\u5728\u4e0d\u540c\u7248\u672c\u7684JDK\u4e2d\uff0c\u8fd9\u4e2a\u987a\u5e8f\u4e5f\u53ef\u80fd\u662f\u4e0d\u540c\u7684\u3002<\/p>\n<p>\u6362\u6210TreeSet\uff1a<\/p>\n<p>\u5728\u904d\u5386TreeSet\u65f6\uff0c\u8f93\u51fa\u5c31\u662f\u6709\u5e8f\u7684\uff0c\u4e0d\u662f\u6dfb\u52a0\u65f6\u7684\u987a\u5e8f\uff0c\u800c\u662f\u5143\u7d20\u7684\u6392\u5e8f\u987a\u5e8f\u3002<\/p>\n<p>\u6ce8\u610f\uff1a\u6dfb\u52a0\u7684\u5143\u7d20\u5fc5\u987b\u5b9e\u73b0Comparable\u63a5\u53e3\uff0c\u5982\u679c\u6ca1\u6709\u5b9e\u73b0Comparable\u63a5\u53e3\uff0c\u90a3\u4e48\u521b\u5efaTreeSet\u65f6\u5fc5\u987b\u4f20\u5165\u4e00\u4e2aComparator\u5bf9\u8c61\u3002<\/p>\n<p>\u5728\u770b\u548c\u8f6c\u53d1\u662f\u5bf9\u7b14\u8005\u6700\u5927\u7684\u6fc0\u52b1\u54e6\uff01<\/p>\n<p>\u516c\u4f17\u53f7\u3010\u6e90\u7801\u7b14\u8bb0\u3011\uff0c\u4e13\u6ce8\u4e8eJava\u540e\u7aef\u7cfb\u5217\u6846\u67b6\u7684\u6e90\u7801\u5206\u6790\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6d45\u8c08 Java \u96c6\u5408 | \u5e95\u5c42\u6e90\u7801\u89e3\u6790\u5728 Java \u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u4f7f\u7528\u5230\u4e00\u4e9b\u5904\u7406\u7f13\u5b58\u6570\u636e\u7684\u96c6\u5408\u7c7b\uff0c\u8fd9\u4e9b\u96c6\u5408\u7c7b\u90fd\u6709\u81ea\u5df1\u7684\u7279\u70b9\uff0c\u4eca\u5929\u4e3b\u8981\u5206\u4eab\u4e0b Java \u96c6\u5408\u4e2d\u51e0\u79cd\u7ecf\u5e38\u7528\u7684 Map\u3001List\u3001Set\u3002<\/p>\n","protected":false},"author":1,"featured_media":309,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"topic":[],"class_list":["post-308","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-1"],"_links":{"self":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts\/308","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/comments?post=308"}],"version-history":[{"count":0,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/posts\/308\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/media\/309"}],"wp:attachment":[{"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/media?parent=308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/categories?post=308"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/tags?post=308"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/www.ccwifi.cc\/blogs\/wp-json\/wp\/v2\/topic?post=308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}