{"id":1179,"date":"2022-10-25T22:52:17","date_gmt":"2022-10-25T14:52:17","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1179"},"modified":"2022-11-27T12:39:49","modified_gmt":"2022-11-27T04:39:49","slug":"%e9%9b%86%e5%90%88-collection%e6%8e%a5%e5%8f%a3%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%952%e3%80%81collection%e6%8e%a5%e5%8f%a3%e7%9a%84%e5%b8%b8%e7%94%a8%e6%96%b9%e6%b3%953%e3%80%81collection","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1179","title":{"rendered":"\u96c6\u5408-Collection\u63a5\u53e3\u7684\u5e38\u7528\u65b9\u6cd52\u3001Collection\u63a5\u53e3\u7684\u5e38\u7528\u65b9\u6cd53\u3001Collection\u63a5\u53e3\u7684\u5e38\u7528\u65b9\u6cd54"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P520;\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.Collection;\r\nimport java.util.List;\r\n\r\n\/**\r\n * Collection\u63a5\u53e3\u4e2d\u58f0\u660e\u7684\u65b9\u6cd5\u7684\u6d4b\u8bd5\r\n *\r\n * \u7ed3\u8bba\uff1a\r\n * \u5411Collection\u63a5\u53e3\u7684\u5b9e\u73b0\u7c7b\u7684\u5bf9\u8c61\u4e2d\u6dfb\u52a0\u6570\u636eobj\u65f6\uff0c\u8981\u6c42obj\u6240\u5728\u7c7b\u8981\u91cd\u5199equals().\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-25 \u4e0b\u5348 9:45\r\n *\/\r\npublic class CollectionTest {\r\n\r\n    @Test\r\n    public void test1(){\r\n        Collection coll = new ArrayList();\r\n        coll.add(123);\r\n        coll.add(456);\r\n\/\/        Person p = new Person(\"Jerry\", 20);\r\n\/\/        coll.add(p);\r\n        coll.add(new Person(\"Jerry\", 20));\r\n        coll.add(new String(\"Tom\"));\r\n        coll.add(false);\r\n\r\n        \/\/1. contains(Object obj):\u5224\u65ad\u5f53\u524d\u96c6\u5408\u4e2d\u662f\u5426\u5305\u542bobj\r\n        \/\/\u6211\u4eec\u5728\u5224\u65ad\u65f6\u4f1a\u8c03\u7528obj\u5bf9\u8c61\u6240\u5728\u7c7b\u7684equals()\u3002\r\n        boolean contains = coll.contains(123);\r\n        System.out.println(contains);\r\n        System.out.println(coll.contains(new String(\"Tom\")));\r\n\/\/        System.out.println(coll.contains(p));\/\/true\r\n        System.out.println(coll.contains(new Person(\"Jerry\", 20)));\/\/false --> true\r\n\r\n        \/\/2. containsAll(Collection coll1):\u5224\u65ad\u5f62\u53c2coll1\u4e2d\u7684\u6240\u6709\u5143\u7d20\u662f\u5426\u90fd\u5b58\u5728\u4e8e\u5f53\u524d\u96c6\u5408\u4e2d\u3002\r\n        Collection coll1 = Arrays.asList(123,4567);\r\n        System.out.println(coll.containsAll(coll1));\r\n\r\n    }\r\n\r\n    @Test\r\n    public void test2(){\r\n        \/\/3. remove(Object obj):\u4ece\u5f53\u524d\u96c6\u5408\u4e2d\u79fb\u9664obj\u5143\u7d20\u3002\r\n        Collection coll = new ArrayList();\r\n        coll.add(123);\r\n        coll.add(456);\r\n        coll.add(new Person(\"Jerry\", 20));\r\n        coll.add(new String(\"Tom\"));\r\n        coll.add(false);\r\n\r\n        coll.remove(1234);\r\n        System.out.println(coll);\r\n\r\n        coll.remove(new Person(\"Jerry\", 20));\r\n        System.out.println(coll);\r\n\r\n        \/\/4. removeAll(Collection coll1):\u5dee\u96c6\uff1a\u4ece\u5f53\u524d\u96c6\u5408\u4e2d\u79fb\u9664coll1\u4e2d\u6240\u6709\u7684\u5143\u7d20\u3002\r\n        Collection coll1 = Arrays.asList(123,456);\r\n        coll.removeAll(coll1);\r\n        System.out.println(coll);\r\n\r\n    }\r\n\r\n    @Test\r\n    public void test3(){\r\n        Collection coll = new ArrayList();\r\n        coll.add(123);\r\n        coll.add(456);\r\n        coll.add(new Person(\"Jerry\", 20));\r\n        coll.add(new String(\"Tom\"));\r\n        coll.add(false);\r\n\r\n        \/\/5. retainAll(Collection coll1):\u4ea4\u96c6\uff1a\u83b7\u53d6\u5f53\u524d\u96c6\u5408\u548ccoll1\u96c6\u5408\u7684\u4ea4\u96c6\uff0c\u5e76\u8fd4\u56de\u7ed9\u5f53\u524d\u96c6\u5408\r\n\/\/        Collection coll1 = Arrays.asList(123,456,789);\r\n\/\/        coll.retainAll(coll1);\r\n\/\/        System.out.println(coll);\r\n\r\n        \/\/6. equals(Object obj):\u8981\u60f3\u8fd4\u56detrue\uff0c\u5224\u65ad\u5f53\u524d\u96c6\u5408\u548c\u5f62\u53c2\u96c6\u5408\u7684\u5143\u7d20\u90fd\u76f8\u540c\u3002\r\n        Collection coll1 = new ArrayList();\r\n        coll1.add(456);\r\n        coll1.add(123);\r\n        coll1.add(new Person(\"Jerry\", 20));\r\n        coll1.add(new String(\"Tom\"));\r\n        coll1.add(false);\r\n\r\n        System.out.println(coll.equals(coll1));\r\n    }\r\n\r\n    @Test\r\n    public void test4(){\r\n        Collection coll = new ArrayList();\r\n        coll.add(123);\r\n        coll.add(456);\r\n        coll.add(new Person(\"Jerry\", 20));\r\n        coll.add(new String(\"Tom\"));\r\n        coll.add(false);\r\n\r\n        \/\/7. hashCode():\u8fd4\u56de\u5f53\u524d\u5bf9\u8c61\u7684\u54c8\u5e0c\u503c\r\n        System.out.println(coll.hashCode());\r\n\r\n        \/\/8. \u96c6\u5408 ---> \u6570\u7ec4\uff1atoArray()\r\n        Object&#91;] arr = coll.toArray();\r\n        for (int i = 0; i &lt; arr.length; i++) {\r\n            System.out.println(arr&#91;i]);\r\n        }\r\n\r\n        \/\/\u62d3\u5c55\uff1a\u6570\u7ec4 ---> \u96c6\u5408:\u8c03\u7528Arrays\u7c7b\u7684\u9759\u6001\u65b9\u6cd5asList()\r\n        List&lt;String> list = Arrays.asList(new String&#91;]{\"AA\", \"BB\", \"CC\"});\r\n        System.out.println(list);\r\n\r\n        List arr1 = Arrays.asList(new int&#91;]{123, 456});\r\n        System.out.println(arr1.size());\/\/1\r\n\r\n        List arr2 = Arrays.asList(new Integer&#91;]{123, 456});\r\n        System.out.println(arr2.size());\/\/2\r\n\r\n        \/\/iterator():\u8fd4\u56deIterator\u63a5\u53e3\u7684\u5b9e\u4f8b\uff0c\u7528\u4e8e\u904d\u5386\u96c6\u5408\u5143\u7d20\u3002\u653e\u5728IteratorTest.java\u4e2d\u6d4b\u8bd5\r\n    }\r\n}\r\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P520;\r\n\r\n\/**\r\n * @author RichieZhang\r\n * @create 2022-10-25 \u4e0b\u5348 9:48\r\n *\/\r\npublic class Person {\r\n\r\n    private String name;\r\n    private int age;\r\n\r\n    public Person() {\r\n    }\r\n\r\n    public Person(String name, int age) {\r\n        this.name = name;\r\n        this.age = age;\r\n    }\r\n\r\n    public String getName() {\r\n        return name;\r\n    }\r\n\r\n    public void setName(String name) {\r\n        this.name = name;\r\n    }\r\n\r\n    public int getAge() {\r\n        return age;\r\n    }\r\n\r\n    public void setAge(int age) {\r\n        this.age = age;\r\n    }\r\n\r\n    @Override\r\n    public String toString() {\r\n        return \"Person{\" +\r\n                \"name='\" + name + '\\'' +\r\n                \", age=\" + age +\r\n                '}';\r\n    }\r\n\r\n    @Override\r\n    public boolean equals(Object o) {\r\n        System.out.println(\"Person equals().....\");\r\n        if (this == o) return true;\r\n        if (o == null || getClass() != o.getClass()) return false;\r\n\r\n        Person person = (Person) o;\r\n\r\n        if (age != person.age) return false;\r\n        return name != null ? name.equals(person.name) : person.name == null;\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-1179","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\/1179"}],"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=1179"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1179\/revisions"}],"predecessor-version":[{"id":1180,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1179\/revisions\/1180"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1179"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1179"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1179"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}