{"id":1236,"date":"2022-10-27T23:02:17","date_gmt":"2022-10-27T15:02:17","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1236"},"modified":"2022-11-27T12:39:47","modified_gmt":"2022-11-27T04:39:47","slug":"%e9%9b%86%e5%90%88-collections%e5%b7%a5%e5%85%b7%e7%b1%bb%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%95%e7%9a%84%e6%b5%8b%e8%af%95","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1236","title":{"rendered":"\u96c6\u5408-Collections\u5de5\u5177\u7c7b\u5e38\u7528\u65b9\u6cd5\u7684\u6d4b\u8bd5"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P559;\r\n\r\nimport org.junit.jupiter.api.Test;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.Arrays;\r\nimport java.util.Collections;\r\nimport java.util.List;\r\n\r\n\/**\r\n * Collections:\u64cd\u4f5cCollection\u3001Map\u7684\u5de5\u5177\u7c7b\r\n *\r\n *\r\n * \u9762\u8bd5\u9898\uff1aCollection \u548c Collections\u7684\u533a\u522b\uff1f\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-27 \u4e0b\u5348 10:06\r\n *\/\r\npublic class CollectionsTest {\r\n\r\n    \/*\r\n    \u6392\u5e8f\u64cd\u4f5c\uff1a\uff08\u5747\u4e3astatic\u65b9\u6cd5\uff09\r\n    \uf0d8reverse(List)\uff1a\u53cd\u8f6c List \u4e2d\u5143\u7d20\u7684\u987a\u5e8f\r\n    \uf0d8shuffle(List)\uff1a\u5bf9 List \u96c6\u5408\u5143\u7d20\u8fdb\u884c\u968f\u673a\u6392\u5e8f\r\n    \uf0d8sort(List)\uff1a\u6839\u636e\u5143\u7d20\u7684\u81ea\u7136\u987a\u5e8f\u5bf9\u6307\u5b9a List \u96c6\u5408\u5143\u7d20\u6309\u5347\u5e8f\u6392\u5e8f\r\n    \uf0d8sort(List\uff0cComparator)\uff1a\u6839\u636e\u6307\u5b9a\u7684 Comparator \u4ea7\u751f\u7684\u987a\u5e8f\u5bf9 List \u96c6\u5408\u5143\u7d20\u8fdb\u884c\u6392\u5e8f\r\n    \uf0d8swap(List\uff0cint\uff0c int)\uff1a\u5c06\u6307\u5b9a list \u96c6\u5408\u4e2d\u7684 i \u5904\u5143\u7d20\u548c j \u5904\u5143\u7d20\u8fdb\u884c\u4ea4\u6362\r\n\r\n    \u67e5\u627e\u3001\u66ff\u6362\r\n    Object max(Collection)\uff1a\u6839\u636e\u5143\u7d20\u7684\u81ea\u7136\u987a\u5e8f\uff0c\u8fd4\u56de\u7ed9\u5b9a\u96c6\u5408\u4e2d\u7684\u6700\u5927\u5143\u7d20\r\n    Object max(Collection\uff0cComparator)\uff1a\u6839\u636e Comparator \u6307\u5b9a\u7684\u987a\u5e8f\uff0c\u8fd4\u56de\u7ed9\u5b9a\u96c6\u5408\u4e2d\u7684\u6700\u5927\u5143\u7d20\r\n    Object min(Collection)\r\n    Object min(Collection\uff0cComparator)\r\n    int frequency(Collection\uff0cObject)\uff1a\u8fd4\u56de\u6307\u5b9a\u96c6\u5408\u4e2d\u6307\u5b9a\u5143\u7d20\u7684\u51fa\u73b0\u6b21\u6570\r\n    void copy(List dest,List src)\uff1a\u5c06src\u4e2d\u7684\u5185\u5bb9\u590d\u5236\u5230dest\u4e2d\r\n    boolean replaceAll(List list\uff0cObject oldVal\uff0cObject newVal)\uff1a\u4f7f\u7528\u65b0\u503c\u66ff\u6362List \u5bf9\u8c61\u7684\u6240\u6709\u65e7\u503c\r\n\r\n     *\/\r\n    @Test\r\n    public void test2(){\r\n        List list = new ArrayList();\r\n        list.add(123);\r\n        list.add(43);\r\n        list.add(765);\r\n        list.add(-97);\r\n        list.add(0);\r\n\r\n        \/\/\u62a5\u5f02\u5e38\uff1aIndexOutOfBoundsException(\"Source does not fit in dest\")\r\n\/\/        List dest = new ArrayList();\r\n\/\/        Collections.copy(dest,list);\r\n        \/\/\u6b63\u786e\u7684\uff1a\r\n        List dest = Arrays.asList(new Object&#91;list.size()]);\r\n        System.out.println(dest.size());\/\/list.size();\r\n        Collections.copy(dest,list);\r\n\r\n        System.out.println(dest);\r\n\r\n        \/*\r\n        Collections \u7c7b\u4e2d\u63d0\u4f9b\u4e86\u591a\u4e2a synchronizedXxx() \u65b9\u6cd5\uff0c\r\n        \u8be5\u65b9\u6cd5\u53ef\u4f7f\u5c06\u6307\u5b9a\u96c6\u5408\u5305\u88c5\u6210\u7ebf\u7a0b\u540c\u6b65\u7684\u96c6\u5408\uff0c\u4ece\u800c\u53ef\u4ee5\u89e3\u51b3\r\n        \u591a\u7ebf\u7a0b\u5e76\u53d1\u8bbf\u95ee\u96c6\u5408\u65f6\u7684\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\r\n\r\n         *\/\r\n\r\n        \/\/\u8fd4\u56de\u7684list1\u5373\u4e3a\u7ebf\u7a0b\u5b89\u5168\u7684List\r\n        List list1 = Collections.synchronizedList(list);\r\n    }\r\n\r\n    @Test\r\n    public void test1(){\r\n        List list = new ArrayList();\r\n        list.add(123);\r\n        list.add(43);\r\n        list.add(765);\r\n        list.add(765);\r\n        list.add(765);\r\n        list.add(-97);\r\n        list.add(0);\r\n\r\n        System.out.println(list);\r\n\r\n\/\/        Collections.reverse(list);\r\n\/\/        Collections.shuffle(list);\r\n\/\/        Collections.sort(list);\r\n\/\/        Collections.swap(list,1,2);\r\n        int frequency = Collections.frequency(list, 123);\r\n\r\n        System.out.println(list);\r\n        System.out.println(frequency);\r\n\r\n\r\n    }\r\n}\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[46],"class_list":["post-1236","post","type-post","status-publish","format-standard","hentry","category-java-code","tag-java"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1236"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1236"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1236\/revisions"}],"predecessor-version":[{"id":1237,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1236\/revisions\/1237"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1236"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1236"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1236"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}