{"id":1292,"date":"2022-10-29T22:48:46","date_gmt":"2022-10-29T14:48:46","guid":{"rendered":"https:\/\/qaqaq.top\/?p=1292"},"modified":"2022-11-27T12:39:47","modified_gmt":"2022-11-27T04:39:47","slug":"%e6%b3%9b%e5%9e%8b%e4%b8%8efile-%e8%87%aa%e5%ae%9a%e4%b9%89%e6%b3%9b%e5%9e%8b%e7%b1%bb%e7%bb%83%e4%b9%a0","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=1292","title":{"rendered":"\u6cdb\u578b\u4e0eFile-\u81ea\u5b9a\u4e49\u6cdb\u578b\u7c7b\u7ec3\u4e60"},"content":{"rendered":"\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P576;\r\n\r\nimport java.util.*;\r\n\r\n\/**\r\n * \u5b9a\u4e49\u4e2a\u6cdb\u578b\u7c7b DAO&lt;T>\uff0c\u5728\u5176\u4e2d\u5b9a\u4e49\u4e00\u4e2a Map \u6210\u5458\u53d8\u91cf\uff0cMap \u7684\u952e\u4e3a String \u7c7b\u578b\uff0c\u503c\u4e3a T \u7c7b\u578b\u3002\u5206\u522b\u521b\u5efa\u4ee5\u4e0b\u65b9\u6cd5\uff1a\r\n * public void save(String id,T entity)\uff1a \u4fdd\u5b58 T \u7c7b\u578b\u7684\u5bf9\u8c61\u5230 Map \u6210\u5458\u53d8\u91cf\u4e2d\r\n * public T get(String id)\uff1a\u4ece map \u4e2d\u83b7\u53d6 id \u5bf9\u5e94\u7684\u5bf9\u8c61\r\n * public void update(String id,T entity)\uff1a\u66ff\u6362 map \u4e2d key \u4e3a id \u7684\u5185\u5bb9,\u6539\u4e3a entity \u5bf9\u8c61\r\n * public List&lt;T> list()\uff1a\u8fd4\u56de map \u4e2d\u5b58\u653e\u7684\u6240\u6709 T \u5bf9\u8c61\r\n * public void delete(String id)\uff1a\u5220\u9664\u6307\u5b9a id \u5bf9\u8c61\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-29 \u4e0b\u5348 1:57\r\n *\/\r\npublic class DAO&lt;T> {\r\n\r\n    private Map&lt;String,T> map = new HashMap&lt;String,T>();\r\n\r\n    \/\/\u4fdd\u5b58 T \u7c7b\u578b\u7684\u5bf9\u8c61\u5230 Map \u6210\u5458\u53d8\u91cf\u4e2d\r\n    public void save(String id, T entiey){\r\n        map.put(id,entiey);\r\n    }\r\n\r\n    \/\/\u4ece map \u4e2d\u83b7\u53d6 id \u5bf9\u5e94\u7684\u5bf9\u8c61\r\n    public T get(String id){\r\n        return map.get(id);\r\n    }\r\n\r\n    \/\/\u66ff\u6362 map \u4e2d key \u4e3a id \u7684\u5185\u5bb9,\u6539\u4e3a entity \u5bf9\u8c61\r\n    public void update(String id, T entity){\r\n        if (map.containsKey(id)){\r\n            map.put(id,entity);\r\n        }\r\n    }\r\n\r\n    \/\/\u8fd4\u56de map \u4e2d\u5b58\u653e\u7684\u6240\u6709 T \u5bf9\u8c61\r\n    public List&lt;T> list(){\r\n        \/\/\u9519\u8bef\u7684\uff1a\r\n\/\/        Collection&lt;T> values = map.values();\r\n\/\/        return (List&lt;T>) values;\r\n        \/\/\u6b63\u786e\u7684\uff1a\r\n        ArrayList&lt;T> list = new ArrayList&lt;>();\r\n        Collection&lt;T> values = map.values();\r\n        for (T t : values) {\r\n            list.add(t);\r\n        }\r\n        return list;\r\n    }\r\n\r\n    \/\/\u5220\u9664\u6307\u5b9a id \u5bf9\u8c61\r\n    public void delete(String id){\r\n        map.remove(id);\r\n    }\r\n}\r\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P576;\r\n\r\n\/**\r\n * \u5b9a\u4e49\u4e00\u4e2a User \u7c7b\uff1a\r\n * \u8be5\u7c7b\u5305\u542b\uff1aprivate \u6210\u5458\u53d8\u91cf\uff08int \u7c7b\u578b\uff09 id\uff0cage\uff1b\uff08String \u7c7b\u578b\uff09name\u3002\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-29 \u4e0b\u5348 2:31\r\n *\/\r\npublic class User {\r\n\r\n    private int id;\r\n    private int age;\r\n    private String name;\r\n\r\n    public User() {\r\n    }\r\n\r\n    public User(int id, int age, String name) {\r\n        this.id = id;\r\n        this.age = age;\r\n        this.name = name;\r\n    }\r\n\r\n    public int getId() {\r\n        return id;\r\n    }\r\n\r\n    public void setId(int id) {\r\n        this.id = id;\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    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    @Override\r\n    public String toString() {\r\n        return \"User{\" +\r\n                \"id=\" + id +\r\n                \", age=\" + age +\r\n                \", name='\" + name + '\\'' +\r\n                '}';\r\n    }\r\n\r\n    @Override\r\n    public boolean equals(Object o) {\r\n        if (this == o) return true;\r\n        if (o == null || getClass() != o.getClass()) return false;\r\n\r\n        User user = (User) o;\r\n\r\n        if (id != user.id) return false;\r\n        if (age != user.age) return false;\r\n        return name != null ? name.equals(user.name) : user.name == null;\r\n    }\r\n\r\n    @Override\r\n    public int hashCode() {\r\n        int result = id;\r\n        result = 31 * result + age;\r\n        result = 31 * result + (name != null ? name.hashCode() : 0);\r\n        return result;\r\n    }\r\n}\r\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>package top.qaqaq.java.P576;\r\n\r\nimport java.util.List;\r\n\r\n\/**\r\n * \u5b9a\u4e49\u4e00\u4e2a\u6d4b\u8bd5\u7c7b\uff1a\r\n * \u521b\u5efa DAO \u7c7b\u7684\u5bf9\u8c61\uff0c \u5206\u522b\u8c03\u7528\u5176 save\u3001get\u3001update\u3001list\u3001delete \u65b9\r\n * \u6cd5\u6765\u64cd\u4f5c User \u5bf9\u8c61\uff0c\r\n * \u4f7f\u7528 Junit \u5355\u5143\u6d4b\u8bd5\u7c7b\u8fdb\u884c\u6d4b\u8bd5\u3002\r\n *\r\n * @author RichieZhang\r\n * @create 2022-10-29 \u4e0b\u5348 2:33\r\n *\/\r\npublic class DAOTest {\r\n\r\n    public static void main(String&#91;] args) {\r\n\r\n        DAO&lt;User> dao = new DAO&lt;User>();\r\n\r\n        dao.save(\"1001\",new User(1001,34,\"\u5468\u6770\u4f26\"));\r\n        dao.save(\"1002\",new User(1002,20,\"\u6606\u51cc\"));\r\n        dao.save(\"1003\",new User(1003,25,\"\u8521\u4f9d\u6797\"));\r\n\r\n        dao.update(\"1003\",new User(1003,30,\"\u65b9\u6587\u5c71\"));\r\n\r\n        dao.delete(\"1002\");\r\n\r\n        List&lt;User> list = dao.list();\r\n\/\/        System.out.println(list);\r\n        list.forEach(System.out::println);\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-1292","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\/1292"}],"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=1292"}],"version-history":[{"count":1,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1292\/revisions"}],"predecessor-version":[{"id":1293,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/1292\/revisions\/1293"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1292"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1292"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1292"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}