{"id":31414,"date":"2022-12-21T23:37:50","date_gmt":"2023-12-27T00:40:35","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/java-%e8%bf%ad%e4%bb%a3%e5%99%a8%e7%9a%84%e5%a4%87%e6%b3%a8\/"},"modified":"2025-08-12T23:55:50","modified_gmt":"2025-08-12T15:55:50","slug":"java-%e8%bf%ad%e4%bb%a3%e5%99%a8%e7%9a%84%e5%a4%87%e6%b3%a8","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/java-%e8%bf%ad%e4%bb%a3%e5%99%a8%e7%9a%84%e5%a4%87%e6%b3%a8\/","title":{"rendered":"[Java] \u8fed\u4ee3\u5668\u7684\u5907\u6ce8"},"content":{"rendered":"<h1>\u76ee\u6807<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">Iterator \u306e\u4f7f\u3044\u3069\u3053\u308d\u306e\u6574\u7406<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u985e\u4f3c\u306e ListIterator \u306b\u3064\u3044\u3066\u3082\u7c21\u5358\u306b<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\u3064\u3044\u3067\u306b\u53e4\u3044\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u306e Enumeration \u3082\u5c11\u3057\u3060\u3051<\/ul>\n<h1>\u5173\u4e8e java.util.Iterator\u4f7f\u7528forEach\u904d\u5386\u96c6\u5408\u7c7b\u7b49\u5143\u7d20\u65f6\u4f7f\u7528\u3002<br \/>\n\u867d\u7136Java5.0\u5f15\u5165\u4e86\u589e\u5f3afor\u5faa\u73af\uff0c\u56e0\u6b64\u5f88\u5c11\u9700\u8981\u660e\u786e\u4f7f\u7528Iterator\u3002\u4f46\u662f\u5728Java8\u4e2d\u589e\u52a0\u4e86\u6d41\u76f8\u5173\u7279\u6027\uff0c\u8fd9\u5c06\u8fdb\u4e00\u6b65\u51cf\u5c11\u4f7f\u7528Iterator\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u6211\u8ba4\u4e3a\u6709\u7684\u60c5\u51b5\u4e0b\u53ef\u80fd\u9700\u8981\u663e\u5f0f\u5730\u4f7f\u7528\u8fed\u4ee3\u5668\u3002<\/p>\n<h2>\u65b9\u6cd5\u5f88\u5bb9\u6613\u3002<\/p>\n<p>Iterator#hasNext() : \u6b21\u306e\u30c7\u30fc\u30bf\u304c\u3042\u308b\u5834\u5408\u306b\u771f<\/p>\n<p>Iterator#next() : \u6b21\u306e\u30c7\u30fc\u30bf\u3092\u53d6\u5f97<\/p>\n<p>Iterator#remove() : \u8aad\u307f\u8fbc\u3093\u3060\u30c7\u30fc\u30bf\u3092\u524a\u9664 (\u30aa\u30d7\u30b7\u30e7\u30f3\u64cd\u4f5c)<\/p>\n<p>Iterator#forEachRemaining() : \u5404\u8981\u7d20\u3092\u9806\u756a\u306b\u51e6\u7406\u3059\u308b(Java8\u3067\u8ffd\u52a0)<\/p>\n<p>\u7531\u4e8e`remove()`\u662f\u4e00\u4e2a\u53ef\u9009\u64cd\u4f5c\uff0c\u56e0\u6b64\u6839\u636e\u4f7f\u7528\u7684`Iterator`\u7684\u4e0d\u540c\uff0c\u53ef\u80fd\u65e0\u6cd5\u8fdb\u884c\u5220\u9664\u64cd\u4f5c\uff08\u4f8b\u5982\uff0c`Collections.unmodifiableList()`\u8fd4\u56de\u7684\u662f\u4e0d\u53ef\u53d8\u5217\u8868\uff0c\u56e0\u6b64\u4ece\u4e2d\u83b7\u53d6\u7684`Iterator`\u65e0\u6cd5\u5220\u9664\u5143\u7d20\uff09\u3002<br \/>\n\u53e6\u5916\u4e00\u63d0\uff0c\u4eceJava8\u5f00\u59cb\uff0c`remove()`\u5df2\u6210\u4e3a\u9ed8\u8ba4\u65b9\u6cd5\u3002<br \/>\n\u9ed8\u8ba4\u5b9e\u73b0\u53ea\u662f\u629b\u51fa`UnsupportedOperationException`\u5f02\u5e38\u800c\u5df2\u3002<\/p>\n<p>\u53e6\u5916\uff0cJava8\u65b0\u589e\u4e86forEachRemaining()\u65b9\u6cd5\uff0c\u5b83\u4e5f\u662f\u9ed8\u8ba4\u65b9\u6cd5\u3002<\/p>\n<h2>\u5220\u9664\u8981\u7d20\u6211\u8ba4\u4e3a\u5fc5\u987b\u660e\u786e\u5904\u7406\u8fed\u4ee3\u5668\u7684\u60c5\u51b5\u51e0\u4e4e\u90fd\u662f\u5728\u60f3\u8981\u5220\u9664\u5143\u7d20\u7684\u60c5\u51b5\u4e0b\u3002<\/p>\n<p>\u5982\u679c\u8981\u4ece\u96c6\u5408\u4e2d\u5220\u9664\u4e0d\u9700\u8981\u7684\u5143\u7d20\u6216\u5df2\u5904\u7406\u8fc7\u7684\u5143\u7d20\uff0c\u6211\u8ba4\u4e3a\u53ef\u4ee5\u6309\u7167\u4ee5\u4e0b\u65b9\u5f0f\u8fdb\u884c\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">List<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"nc\">Iterator<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">iterator<\/span> <span class=\"o\">=<\/span> <span class=\"n\">list<\/span><span class=\"o\">.<\/span><span class=\"na\">iterator<\/span><span class=\"o\">();<\/span>\r\n<span class=\"k\">while<\/span> <span class=\"o\">(<\/span><span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">hasNext<\/span><span class=\"o\">())<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">=<\/span> <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">next<\/span><span class=\"o\">();<\/span>\r\n\t<span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 0 \u306f\u524a\u9664<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n    <span class=\"o\">}<\/span>\r\n<span class=\"o\">}<\/span>\r\n\r\n<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">list<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ -&gt; [3, 1, 4, 1, 5, 9, 2, 6]<\/span>\r\n<\/code><\/pre>\n<p>remove() \u51fd\u6570\u7528\u4e8e\u5220\u9664\u524d\u4e00\u4e2a next() \u51fd\u6570\u8fd4\u56de\u7684\u5143\u7d20\u3002<br \/>\n\u56e0\u6b64\uff0c\u5728\u6ca1\u6709\u8c03\u7528 next() \u51fd\u6570\u6216\u5df2\u7ecf\u8c03\u7528 remove() \u51fd\u6570\u7684\u60c5\u51b5\u4e0b\uff0c\u4e0d\u53ef\u4ee5\u8c03\u7528 remove() \u51fd\u6570\uff08\u4f1a\u629b\u51fa\u5f02\u5e38\uff09\u3002<\/p>\n<h1>\u5173\u4e8ejava.util.ListIterator\u5728Iterator\u4e4b\u5916\uff0c\u8fd8\u6709\u4e00\u4e2a\u6bd4\u8f83\u4e0d\u5e38\u89c1\u7684ListIterator\u3002<br \/>\n\u987e\u540d\u601d\u4e49\uff0c\u5b83\u662f\u4e13\u4e3a\u5217\u8868\u800c\u6269\u5c55\u7684\u8fed\u4ee3\u5668\u3002<\/p>\n<p>ListIterator \u548c Iterator \u7684\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\u5b83\u53ef\u4ee5\u5411\u53cd\u65b9\u5411\u79fb\u52a8\uff0c\u5e76\u4e14\u53ef\u4ee5\u6dfb\u52a0\u548c\u66ff\u6362\u5143\u7d20\u3002\u6b64\u5916\uff0cIterator \u53ea\u80fd\u4ece\u5934\u90e8\u83b7\u53d6\u5143\u7d20\uff0c\u800c ListIterator \u53ef\u4ee5\u4ece\u5217\u8868\u7684\u4efb\u610f\u4f4d\u7f6e\u83b7\u53d6\u5143\u7d20\u3002<\/p>\n<h2>\u65b9\u6cd5ListIterator#hasNext() : \u6b21\u306e\u30c7\u30fc\u30bf\u304c\u3042\u308b\u5834\u5408\u306b\u771f<\/p>\n<p>ListIterator#next() : \u6b21\u306e\u30c7\u30fc\u30bf\u3092\u53d6\u5f97<\/p>\n<p>ListIterator#hasPrevious() : \u524d\u306e\u30c7\u30fc\u30bf\u304c\u3042\u308b\u5834\u5408\u306b\u771f<\/p>\n<p>ListIterator#previous() : \u524d\u306e\u30c7\u30fc\u30bf\u3092\u53d6\u5f97<\/p>\n<p>ListIterator#remove() : \u8aad\u307f\u8fbc\u3093\u3060\u30c7\u30fc\u30bf\u3092\u524a\u9664 (\u30aa\u30d7\u30b7\u30e7\u30f3\u64cd\u4f5c)<\/p>\n<p>ListIterator#forEachRemaining() : \u5404\u8981\u7d20\u3092\u9806\u756a\u306b\u51e6\u7406\u3059\u308b(Java8\u3067\u8ffd\u52a0)<\/p>\n<p>ListIterator#add() : next() \u3067\u8fd4\u3063\u3066\u304f\u308b\u8981\u7d20\u306e\u624b\u524d\u306b\u30c7\u30fc\u30bf\u3092\u8ffd\u52a0 (\u30aa\u30d7\u30b7\u30e7\u30f3\u64cd\u4f5c)<\/p>\n<p>ListIterator#set() : \u8aad\u307f\u8fbc\u3093\u3060\u30c7\u30fc\u30bf\u3092\u7f6e\u304d\u63db\u3048 (\u30aa\u30d7\u30b7\u30e7\u30f3\u64cd\u4f5c)<\/p>\n<p>ListIterator#nextIndex() : next() \u3067\u8fd4\u3063\u3066\u304f\u308b\u8981\u7d20\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9(\u672b\u5c3e\u306e\u5834\u5408\u306b\u306f\u3001\u30ea\u30b9\u30c8\u306e\u30b5\u30a4\u30ba)<\/p>\n<p>ListIterator#previousIndex() : previous() \u3067\u8fd4\u3063\u3066\u304f\u308b\u8981\u7d20\u306e\u30a4\u30f3\u30c7\u30c3\u30af\u30b9(\u5148\u982d\u306e\u5834\u5408\u306b\u306f\u3001-1)<\/p>\n<h2>\u83b7\u53d6ListIterator\u5728\u4e2d\u6587\u4e2d\uff0c\u901a\u5e38\u901a\u8fc7List#listIterator()\u65b9\u6cd5\u83b7\u53d6ListIterator\u3002<\/p>\n<p>\u5982\u679c\u6ca1\u6709\u53c2\u6570\uff0c\u5219\u83b7\u53d6\u4ece\u5934\u5f00\u59cb\u7684 ListIterator\u3002<\/p>\n<p>\u5982\u679c\u6709\u53c2\u6570\uff0c\u5c06\u4ece\u6307\u5b9a\u4f4d\u7f6e\u83b7\u53d6ListIterator\u3002<\/p>\n<p>\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u540d\u4e3atarget\u7684\u5217\u8868\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u5f15\u6570\u306a\u3057\u3068\u540c\u3058\u4f4d\u7f6e\u306f target.listIterator(0)<\/ul>\n<\/li>\n<\/ul>\n<p>\u5148\u982d\uff11\u3064\u3092\u98db\u3070\u3059\u5834\u5408\u306f target.listIterator(1)<\/p>\n<p>\u4e00\u756a\u6700\u5f8c\u304b\u3089\u306e\u5834\u5408\u306f target.listIterator(target.size())<\/p>\n<h2>\u5982\u679c\u8981\u6dfb\u52a0\u8981\u7d20\u7684\u8bdd<br \/>\n\u5982\u679c\u60f3\u8981\u6dfb\u52a0\u5217\u8868\u7684\u5143\u7d20\uff0c\u53ef\u4ee5\u4f7f\u7528 add() \u65b9\u6cd5\u3002<br \/>\n\u4f8b\u5982\uff0c\u4e0b\u9762\u662f\u5c06\u5df2\u6709\u5143\u7d20\u5206\u5272\u4e3a\u591a\u4e2a\u7684\u60c5\u51b5\u793a\u4f8b\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">List<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"nc\">ListIterator<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">iterator<\/span> <span class=\"o\">=<\/span> <span class=\"n\">list<\/span><span class=\"o\">.<\/span><span class=\"na\">listIterator<\/span><span class=\"o\">();<\/span>\r\n<span class=\"k\">while<\/span> <span class=\"o\">(<\/span><span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">hasNext<\/span><span class=\"o\">())<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">=<\/span> <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">next<\/span><span class=\"o\">();<\/span>\r\n\t<span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 0 \u306f\u524a\u9664<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">%<\/span> <span class=\"mi\">2<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 2 \u3067\u5272\u308a\u5207\u308c\u308b\u5834\u5408\u306b\u306f\u3001\u5206\u5272<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\t\t<span class=\"kt\">int<\/span> <span class=\"n\">sub<\/span> <span class=\"o\">=<\/span> <span class=\"n\">num<\/span> <span class=\"o\">\/<\/span> <span class=\"mi\">2<\/span><span class=\"o\">;<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n    <span class=\"o\">}<\/span>\r\n<span class=\"o\">}<\/span>\r\n\r\n<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">list<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ -&gt; [3, 1, 2, 2, 1, 5, 9, 1, 1, 3, 3]<\/span>\r\n<\/code><\/pre>\n<p>\u901a\u8fc7add() \u65b9\u6cd5\u6dfb\u52a0\u7684\u5143\u7d20\u4f1a\u5728previous() \u65b9\u5411\u4e0a\u6dfb\u52a0\u3002<br \/>\n\u4e5f\u5c31\u662f\u8bf4\uff0c\u4f1a\u53d8\u6210\u4ee5\u4e0b\u8fd9\u6837\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u6b21\u306b next() \u3092\u547c\u3073\u51fa\u3057\u3066\u3082\u53d6\u5f97\u3067\u304d\u306a\u3044<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\u6b21\u306b previous() \u3092\u547c\u3073\u51fa\u3059\u3068\u53d6\u5f97\u3067\u304d\u308b<\/ul>\n<p>\u4e4b\u524d\u5148\u5220\u9664\u4e86\u5143\u7d20\u518d\u6dfb\u52a0\uff0c\u4f46\u662f\u7b80\u5355\u5730\u8fdb\u884c\u6dfb\u52a0\u4f1a\u53d8\u6210\u4ee5\u4e0b\u8fd9\u6837\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">List<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"nc\">ListIterator<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">iterator<\/span> <span class=\"o\">=<\/span> <span class=\"n\">list<\/span><span class=\"o\">.<\/span><span class=\"na\">listIterator<\/span><span class=\"o\">();<\/span>\r\n<span class=\"k\">while<\/span> <span class=\"o\">(<\/span><span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">hasNext<\/span><span class=\"o\">())<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">=<\/span> <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">next<\/span><span class=\"o\">();<\/span>\r\n\t<span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 0 \u306f\u524a\u9664<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">%<\/span> <span class=\"mi\">2<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 2 \u3067\u5272\u308a\u5207\u308c\u308b\u5834\u5408\u306b\u306f\u3001\u5206\u5272<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\t\t<span class=\"kt\">int<\/span> <span class=\"n\">sub<\/span> <span class=\"o\">=<\/span> <span class=\"n\">num<\/span> <span class=\"o\">\/<\/span> <span class=\"mi\">2<\/span><span class=\"o\">;<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">1<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 1 \u306e\u5f8c\u306b\u306f 999 \u3092\u8ffd\u52a0<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"mi\">999<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n\t<span class=\"o\">}<\/span>\r\n<span class=\"o\">}<\/span>\r\n\r\n<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">list<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ -&gt; [3, 1, 999, 2, 2, 1, 999, 5, 9, 1, 1, 3, 3]<\/span>\r\n<\/code><\/pre>\n<h2>\u5982\u679c\u60f3\u8981\u66ff\u6362\u8981\u7d20<br \/>\n\u5982\u679c\u60a8\u60f3\u66ff\u6362\u5217\u8868\u7684\u5143\u7d20\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528set()\u51fd\u6570\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">List<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"nc\">ListIterator<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">iterator<\/span> <span class=\"o\">=<\/span> <span class=\"n\">list<\/span><span class=\"o\">.<\/span><span class=\"na\">listIterator<\/span><span class=\"o\">();<\/span>\r\n<span class=\"k\">while<\/span> <span class=\"o\">(<\/span><span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">hasNext<\/span><span class=\"o\">())<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">=<\/span> <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">next<\/span><span class=\"o\">();<\/span>\r\n\t<span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 0 \u306f\u524a\u9664<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">%<\/span> <span class=\"mi\">2<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 2 \u3067\u5272\u308a\u5207\u308c\u308b\u5834\u5408\u306b\u306f\u3001\u5206\u5272<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\t\t<span class=\"kt\">int<\/span> <span class=\"n\">sub<\/span> <span class=\"o\">=<\/span> <span class=\"n\">num<\/span> <span class=\"o\">\/<\/span> <span class=\"mi\">2<\/span><span class=\"o\">;<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">1<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 1 \u306e\u5f8c\u306b\u306f 999 \u3092\u8ffd\u52a0<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"mi\">999<\/span><span class=\"o\">);<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">5<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 5 \u306f 25 \u306b\u7f6e\u63db<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">set<\/span><span class=\"o\">(<\/span><span class=\"mi\">25<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n\t<span class=\"o\">}<\/span>\r\n<span class=\"o\">}<\/span>\r\n\r\n<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">list<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ -&gt; [3, 1, 999, 2, 2, 1, 999, 25, 9, 1, 1, 3, 3]<\/span>\r\n<\/code><\/pre>\n<p>set() \u65b9\u6cd5\u7528\u4e8e\u66ff\u6362\u4e0a\u4e00\u6b21 next() \u6216 previous() \u8fd4\u56de\u7684\u5143\u7d20\u3002\u56e0\u6b64\uff0c\u5728\u4ee5\u4e0b\u60c5\u51b5\u4e0b\u4f1a\u5f15\u53d1\u5f02\u5e38\u3002<\/p>\n<p>next() \u3042\u308b\u3044\u306f previous() \u3092\u547c\u3073\u51fa\u3059\u524d<\/p>\n<p>add() \u3042\u308b\u3044\u306f remove() \u3092\u547c\u3073\u51fa\u3057\u305f\u5f8c<\/p>\n<p>\u987a\u4fbf\u63d0\u4e00\u4e0b\uff0cremove() \u65b9\u6cd5\u4e5f\u4f1a\u5220\u9664\u4e0a\u6b21\u8c03\u7528 next() \u6216 previous() \u8fd4\u56de\u7684\u5143\u7d20\u3002<\/p>\n<h2>\u5982\u679c\u60f3\u8981\u671d\u76f8\u53cd\u7684\u65b9\u5411\u524d\u8fdb\u552f\u4e00\u7684\u9009\u62e9\u3002<br \/>\n\u8fed\u4ee3\u5668\u53ea\u80fd\u987a\u5e8f\u524d\u8fdb\uff0c\u4f46\u662f\u5217\u8868\u8fed\u4ee3\u5668\u53ef\u4ee5\u9006\u5411\u524d\u8fdb\u3002<\/p>\n<p>\u4ee5\u4e0b\u7684\u4f8b\u5b50\u5c55\u793a\u4e86\u5f53\u5c06\u5143\u7d20\u5206\u5272\u6210\u591a\u4e2a\u90e8\u5206\u540e\uff0c\u60f3\u8981\u5bf9\u5206\u5272\u540e\u7684\u5143\u7d20\u8fdb\u4e00\u6b65\u5904\u7406\u7684\u573a\u666f\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">List<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"nc\">ListIterator<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">iterator<\/span> <span class=\"o\">=<\/span> <span class=\"n\">list<\/span><span class=\"o\">.<\/span><span class=\"na\">listIterator<\/span><span class=\"o\">();<\/span>\r\n<span class=\"k\">while<\/span> <span class=\"o\">(<\/span><span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">hasNext<\/span><span class=\"o\">())<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">=<\/span> <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">next<\/span><span class=\"o\">();<\/span>\r\n\t<span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 0 \u306f\u524a\u9664<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">%<\/span> <span class=\"mi\">2<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">0<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 2 \u3067\u5272\u308a\u5207\u308c\u308b\u5834\u5408\u306b\u306f\u3001\u5206\u5272<\/span>\r\n        <span class=\"c1\">\/\/ \u3055\u3089\u306b\u5206\u5272\u3057\u305f\u3082\u306e\u3082\u51e6\u7406\u3059\u308b<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">remove<\/span><span class=\"o\">();<\/span>\r\n\t\t<span class=\"kt\">int<\/span> <span class=\"n\">sub<\/span> <span class=\"o\">=<\/span> <span class=\"n\">num<\/span> <span class=\"o\">\/<\/span> <span class=\"mi\">2<\/span><span class=\"o\">;<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"n\">sub<\/span><span class=\"o\">);<\/span>\r\n        <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">previous<\/span><span class=\"o\">();<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n        <span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">previous<\/span><span class=\"o\">();<\/span> <span class=\"c1\">\/\/ \u2605<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">1<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 1 \u306e\u5f8c\u306b\u306f 999 \u3092\u8ffd\u52a0<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">add<\/span><span class=\"o\">(<\/span><span class=\"mi\">999<\/span><span class=\"o\">);<\/span>\r\n\r\n\t<span class=\"o\">}<\/span> <span class=\"k\">else<\/span> <span class=\"k\">if<\/span> <span class=\"o\">(<\/span><span class=\"n\">num<\/span> <span class=\"o\">==<\/span> <span class=\"mi\">5<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t\t<span class=\"c1\">\/\/ 5 \u306f 25 \u306b\u7f6e\u63db<\/span>\r\n\t\t<span class=\"n\">iterator<\/span><span class=\"o\">.<\/span><span class=\"na\">set<\/span><span class=\"o\">(<\/span><span class=\"mi\">25<\/span><span class=\"o\">);<\/span>\r\n\t<span class=\"o\">}<\/span>\r\n<span class=\"o\">}<\/span>\r\n\r\n<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">list<\/span><span class=\"o\">);<\/span> <span class=\"c1\">\/\/ -&gt; [3, 1, 999, 1, 999, 1, 999, 1, 999, 1, 999, 1, 999, 25, 9, 1, 999, 1, 999, 3, 3]<\/span>\r\n<\/code><\/pre>\n<p>\u6709\u65f6\u5019\uff0c\u53ef\u80fd\u5e0c\u671b\u4ece\u5217\u8868\u7684\u672b\u5c3e\u5f00\u59cb\u5904\u7406\u3002<br \/>\n\u8fd9\u79cd\u60c5\u51b5\u4e0b\u53ef\u4ee5\u4f7f\u7528 hasPrevious() \u548c previous() \u66ff\u4ee3 hasNext() \u548c next() \u6765\u5b9e\u73b0\u3002<\/p>\n<p>\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u7531\u4e8eadd()\u662f\u5411previous()\u65b9\u5411\u6dfb\u52a0\u7684\uff0c\u6240\u4ee5\u5728\u63a5\u4e0b\u6765\u7684previous()\u8c03\u7528\u4e4b\u540e\u4f1a\u8fd4\u56de\u7ed3\u679c\u3002<\/p>\n<h1>\u5173\u4e8ejava.util.Enumeration<br \/>\n\u7531\u4e8e\u8fd9\u662f\u4e00\u4e2a\u65e7\u7684\u96c6\u5408\u5e93\uff0c\u57fa\u672c\u4e0a\u4e0d\u4f1a\u4f7f\u7528\u5b83&#8230;&#8230;\u867d\u7136\u6211\u60f3\u8bf4\u7684\u662f\u5982\u6b64\uff0c\u4f46\u662f\u7531\u4e8e\u65e7\u7684\u5e93\u4e2d\u6709\u4e00\u4e9b\u76f4\u63a5\u8fd4\u56de Enumeration \u7684\u65b9\u6cd5\uff0c\u6240\u4ee5\u5076\u5c14\u8fd8\u662f\u9700\u8981\u4f7f\u7528\u5b83\u3002<\/p>\n<p>\u7531\u4e8eJava9\u65b0\u589e\u4e86\u540d\u4e3aasIterator\uff08\uff09\u7684\u9ed8\u8ba4\u65b9\u6cd5\uff0c\u56e0\u6b64\u8fed\u4ee3\u5668\u5316\u4e5f\u53d8\u5f97\u66f4\u52a0\u7b80\u5355\u3002<\/p>\n<pre class=\"post-pre\"><code>  <span class=\"n\">enumeration<\/span><span class=\"o\">.<\/span><span class=\"na\">asIterator<\/span><span class=\"o\">().<\/span><span class=\"na\">forEachRemaining<\/span><span class=\"o\">(<\/span><span class=\"n\">i<\/span> <span class=\"o\">-&gt;<\/span> <span class=\"n\">foo<\/span><span class=\"o\">(<\/span><span class=\"n\">i<\/span><span class=\"o\">));<\/span>\r\n<\/code><\/pre>\n<p>\u5728\u4f7f\u7528Collections#list()\u65b9\u6cd5\u65f6\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u5176\u653e\u5165\u53e6\u4e00\u4e2aList\u4e2d\uff0c\u8fd9\u6837\u5728\u4f7f\u7528\u6269\u5c55for\u5faa\u73af\u8fdb\u884c\u5904\u7406\u65f6\u975e\u5e38\u65b9\u4fbf\u3002\u4e0d\u8fc7\u5982\u679c\u6570\u636e\u91cf\u8f83\u5927\u65f6\uff0c\u53ef\u80fd\u4f1a\u611f\u5230\u6709\u4e9b\u6d6a\u8d39\uff0c\u8ba9\u4eba\u6709\u4e9b\u62c5\u5fc3\u3002<\/p>\n<pre class=\"post-pre\"><code>  <span class=\"k\">for<\/span> <span class=\"o\">(<\/span><span class=\"kt\">var<\/span> <span class=\"n\">i<\/span> <span class=\"o\">:<\/span> <span class=\"nc\">Collections<\/span><span class=\"o\">.<\/span><span class=\"na\">list<\/span><span class=\"o\">(<\/span><span class=\"n\">enumeration<\/span><span class=\"o\">))<\/span> <span class=\"o\">{<\/span>\r\n    <span class=\"n\">foo<\/span><span class=\"o\">(<\/span><span class=\"n\">i<\/span><span class=\"o\">);<\/span>\r\n  <span class=\"o\">}<\/span>\r\n<\/code><\/pre>\n<p>\u76f8\u53cd\u5730\uff0c\u5982\u679c\u60f3\u5c06\u73b0\u6709\u7684 Collection \u8f6c\u5316\u4e3a Enumeration\uff0c\u53ef\u4ee5\u4f7f\u7528 Collections#enumeration() \u65b9\u6cd5\u3002<\/p>\n<pre class=\"post-pre\"><code>  <span class=\"nd\">@Override<\/span>\r\n  <span class=\"kd\">public<\/span> <span class=\"nc\">Enumeration<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">String<\/span><span class=\"o\">&gt;<\/span> <span class=\"nf\">getHeaderNames<\/span><span class=\"o\">()<\/span> <span class=\"o\">{<\/span>\r\n    <span class=\"k\">return<\/span> <span class=\"nc\">Collections<\/span><span class=\"o\">.<\/span><span class=\"na\">enumeration<\/span><span class=\"o\">(<\/span><span class=\"n\">map<\/span><span class=\"o\">.<\/span><span class=\"na\">keySet<\/span><span class=\"o\">());<\/span>\r\n  <span class=\"o\">}<\/span>\r\n<\/code><\/pre>\n<h1>\u5176\u4ed6<\/p>\n<h2>\u7a7a\u7684\u8fed\u4ee3\u5668\u7b49\u6211\u89c9\u5f97\u4e0d\u592a\u5e38\u7528\uff0c\u4f46\u81eaJava7\u5f00\u59cb\u4e5f\u63d0\u4f9b\u4e86\u83b7\u53d6\u7a7aIterator\u7b49\u65b9\u6cd5\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">Collections#emptyIterator()<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">Collections#emptyListIterator()<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">Collections#emptyEnumeration()<\/ul>\n<h2>\u5982\u679c\u76f4\u63a5\u8fd4\u56deIterator\u7684\u60c5\u51b5\u5728\u4e00\u4e9b\u5e93\u4e2d\uff0c\u9664\u4e86Iterable#iterator()\u65b9\u6cd5\u4e4b\u5916\uff0c\u8fd8\u6709\u76f4\u63a5\u8fd4\u56deIterator\u7684\u65b9\u6cd5\u3002<br \/>\n\u6216\u8005\u67d0\u4e9b\u65b9\u6cd5\u540d\u4e3aiterator()\uff0c\u5374\u6ca1\u6709\u5b9e\u73b0Iterable\uff0c\u6216\u8005\u65b9\u6cd5\u540d\u4e0d\u540c\u7b49\u60c5\u51b5\u53ef\u80fd\u5b58\u5728\u3002<\/p>\n<p>\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff08\u5982\u679c\u662fJava8\u53ca\u4ee5\u4e0a\u7248\u672c\uff09\uff0c\u53ef\u4ee5\u4f7f\u7528lambda\u8868\u8fbe\u5f0f\u6216\u65b9\u6cd5\u5f15\u7528\u6765\u5c06\u5176\u8f6c\u6362\u4e3a\u53ef\u8fed\u4ee3\u5bf9\u8c61\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;<\/span> <span class=\"n\">list<\/span> <span class=\"o\">=<\/span> <span class=\"k\">new<\/span> <span class=\"nc\">LinkedList<\/span><span class=\"o\">&lt;&gt;(<\/span><span class=\"nc\">Arrays<\/span><span class=\"o\">.<\/span><span class=\"na\">asList<\/span><span class=\"o\">(<\/span><span class=\"mi\">0<\/span><span class=\"o\">,<\/span> <span class=\"mi\">3<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">4<\/span><span class=\"o\">,<\/span> <span class=\"mi\">1<\/span><span class=\"o\">,<\/span> <span class=\"mi\">5<\/span><span class=\"o\">,<\/span> <span class=\"mi\">9<\/span><span class=\"o\">,<\/span> <span class=\"mi\">2<\/span><span class=\"o\">,<\/span> <span class=\"mi\">6<\/span><span class=\"o\">));<\/span>\r\n\r\n<span class=\"c1\">\/\/ \u9006\u9806\u306b\u51e6\u7406\u3059\u308b<\/span>\r\n<span class=\"k\">for<\/span> <span class=\"o\">(<\/span><span class=\"kt\">int<\/span> <span class=\"n\">num<\/span> <span class=\"o\">:<\/span> <span class=\"o\">(<\/span><span class=\"nc\">Iterable<\/span><span class=\"o\">&lt;<\/span><span class=\"nc\">Integer<\/span><span class=\"o\">&gt;)<\/span> <span class=\"nl\">list:<\/span><span class=\"o\">:<\/span><span class=\"n\">descendingIterator<\/span><span class=\"o\">)<\/span> <span class=\"o\">{<\/span>\r\n\t<span class=\"nc\">System<\/span><span class=\"o\">.<\/span><span class=\"na\">out<\/span><span class=\"o\">.<\/span><span class=\"na\">println<\/span><span class=\"o\">(<\/span><span class=\"n\">num<\/span><span class=\"o\">);<\/span>\r\n<span class=\"o\">}<\/span>\r\n<\/code><\/pre>\n<p>\u5f88\u9057\u61be\uff0c\u7531\u4e8e\u4e0d\u80fd\u76f4\u63a5\u7f16\u5199lambda\u8868\u8fbe\u5f0f\u6216\u65b9\u6cd5\u5f15\u7528\uff0c\u6240\u4ee5\u9700\u8981\u8fdb\u884c\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\u3002<\/p>\n<h2>\u628a\u8fed\u4ee3\u5668\u8f6c\u6362\u4e3a\u6d41\u53c2\u8003\uff1a\u5c06Iterator\u8f6c\u6362\u4e3aStream<\/p>\n<h2>\u57fa\u672c\u7c7b\u578b\u7684\u8fed\u4ee3\u5668 (Ji Ben Lei Xing De Die Dai Qi)Java8\u65b0\u589e\u4e86\u4e00\u4e2a\u540d\u4e3ajava.util.PrimitiveIterator\u7684\u8fed\u4ee3\u5668\u63a5\u53e3\uff0c\u4e13\u95e8\u7528\u4e8e\u539f\u59cb\u7c7b\u578b\u3002\u5b9e\u9645\u4e0a\uff0c\u6211\u8ba4\u4e3a\u4f1a\u5b9e\u73b0\u8bf8\u5982PrimitiveIterator.OfInt\u7b49\u5b50\u63a5\u53e3\u3002<\/p>\n<p>\u5982\u679c\u4f7f\u7528\u901a\u5e38\u7684\u8fed\u4ee3\u5668\uff0c\u5b83\u4f1a\u81ea\u52a8\u88c5\u7bb1\uff0c\u4f46\u4f7f\u7528\u6dfb\u52a0\u7684\u65b9\u6cd5\u53ef\u4ee5\u4fdd\u6301\u539f\u59cb\u6570\u636e\u7c7b\u578b\u3002<br \/>\n\u5982\u679c\u8981\u521b\u5efa\u539f\u59cb\u6570\u636e\u7c7b\u578b\u7684\u8fed\u4ee3\u5668\uff0c\u53ef\u80fd\u53ef\u4ee5\u5b9e\u73b0\u8fd9\u4e2a\u63a5\u53e3\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u76ee\u6807 Iterator \u306e\u4f7f\u3044\u3069\u3053\u308d\u306e\u6574\u7406 &nbsp; \u985e\u4f3c\u306e ListIterator \u306b\u3064\u3044\u3066\u3082\u7c21\u5358\u306b  [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[227],"class_list":["post-31414","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-227"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>[Java] \u8fed\u4ee3\u5668\u7684\u5907\u6ce8 - Blog - Silicon Cloud<\/title>\n<meta name=\"description\" content=\"\u5173\u4e8e[Java] \u8fed\u4ee3\u5668\u7684\u5907\u6ce8\u7684\u6280\u672f\u6587\u7ae0\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/zh\/blog\/java-\u8fed\u4ee3\u5668\u7684\u5907\u6ce8\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" 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