{"id":1581,"date":"2026-06-15T08:35:34","date_gmt":"2026-06-15T00:35:34","guid":{"rendered":"https:\/\/yunyanglib.cn\/?p=1581"},"modified":"2026-06-15T08:35:35","modified_gmt":"2026-06-15T00:35:35","slug":"%e3%80%90java%e3%80%91objects-%e5%b7%a5%e5%85%b7%e7%b1%bb%e5%85%a8%e8%a7%a3%ef%bd%9c%e5%91%8a%e5%88%ab%e7%a9%ba%e6%8c%87%e9%92%88%ef%bc%8c%e5%bc%80%e5%8f%91%e5%bf%85%e5%a4%87%e5%b7%a5%e5%85%b7","status":"publish","type":"post","link":"https:\/\/yunyanglib.cn\/?p=1581","title":{"rendered":"\u3010Java\u3011Objects \u5de5\u5177\u7c7b\u5168\u89e3\uff5c\u544a\u522b\u7a7a\u6307\u9488\uff0c\u5f00\u53d1\u5fc5\u5907\u5de5\u5177\u7c7b"},"content":{"rendered":"\n

\u5927\u5bb6\u597d\uff0c\u6211\u662f\u4e91\u626c\u3002\u65e5\u5e38 Java \u5f00\u53d1\u91cc\uff0c\u7a7a\u6307\u9488\u5f02\u5e38\uff08NullPointerException\uff09<\/strong> \u7edd\u5bf9\u662f\u9ad8\u9891\u8e29\u5751\u70b9\uff0c\u9891\u7e41\u624b\u5199if(obj == null)<\/code>\u4e0d\u4ec5\u4ee3\u7801\u5570\u55e6\uff0c\u8fd8\u5bb9\u6613\u9057\u6f0f\u5224\u65ad\u3002JDK1.8 \u65b0\u589e\u7684java.util.Objects<\/code>\u5de5\u5177\u7c7b\u5c01\u88c5\u4e86\u5404\u7c7b\u5bf9\u8c61\u5b89\u5168\u64cd\u4f5c\u65b9\u6cd5\uff0c\u4e13\u95e8\u7528\u6765\u4f18\u96c5\u5904\u7406\u7a7a\u503c\u6821\u9a8c\u3001\u5bf9\u8c61\u6bd4\u5bf9\u3001\u54c8\u5e0c\u53d6\u503c\u7b49\u573a\u666f\uff0c\u4eca\u5929\u7ed3\u5408\u5b9e\u6218\u4ee3\u7801\uff0c\u4e00\u6b21\u6027\u68b3\u7406 Objects \u5168\u90e8\u5e38\u7528 API\u3002<\/p>\n\n\n\n

\u4e00\u3001\u524d\u7f6e\u5bfc\u5165<\/h2>\n\n\n\n

Objects \u4f4d\u4e8ejava.util<\/code>\u5305\u4e0b\uff0c\u4f7f\u7528\u524d\u5fc5\u987b\u5148\u5bfc\u5305\uff1a<\/p>\n\n\n\n

import java.util.Objects;\nimport java.util.Comparator;\n<\/code><\/pre>\n\n\n\n
\u4e8c\u3001\u57fa\u7840\u5224\u7a7a\uff1aisNull () & nonNull ()<\/h2>\n\n\n\n
\u66ff\u4ee3\u539f\u751f==null \/ !=null<\/code>\u505a\u5bf9\u8c61\u7a7a\u5224\u65ad\uff0c\u4ee3\u7801\u8bed\u4e49\u66f4\u76f4\u89c2\uff0c\u63a8\u8350\u9879\u76ee\u4e2d\u7edf\u4e00\u89c4\u8303\u4f7f\u7528\u3002<\/p>\n\n\n\n
    \n
  • isNull(Object obj)<\/code>\uff1a\u5bf9\u8c61\u4e3a null \u8fd4\u56de true\uff0c\u53cd\u4e4b false<\/li>\n\n\n\n
  • nonNull(Object obj)<\/code>\uff1a\u5bf9\u8c61\u975e null \u8fd4\u56de true\uff0c\u53cd\u4e4b false<\/li>\n<\/ul>\n\n\n\n
    \u4ee3\u7801\u793a\u4f8b<\/h3>\n\n\n\n
    public class ObjectsTest {\n    public static void main(String[] args) {\n        String str1 = null;\n        String str2 = \"\u4e91\u626c\u306eBlog\";\n\n        \/\/ isNull \u5224\u65ad\u662f\u5426\u4e3a\u7a7a\n        System.out.println(Objects.isNull(str1));  \/\/ true\n        System.out.println(Objects.isNull(str2));  \/\/ false\n\n        \/\/ nonNull \u5224\u65ad\u662f\u5426\u975e\u7a7a\n        System.out.println(Objects.nonNull(str1)); \/\/ false\n        System.out.println(Objects.nonNull(str2)); \/\/ true\n\n        \/\/ \u4e1a\u52a1\u573a\u666f\uff1a\u96c6\u5408\u8fc7\u6ee4\u975e\u7a7a\u5143\u7d20\n        \/\/ list.stream().filter(Objects::nonNull).forEach(System.out::println);\n    }\n}\n<\/code><\/pre>\n\n\n\n
    \n
    \u5f00\u53d1\u5c0f\u6280\u5de7\uff1aStream \u6d41\u8fc7\u6ee4\u7a7a\u5143\u7d20\u65f6\uff0cObjects::nonNull<\/code>\u662f\u6700\u4f18\u5199\u6cd5\uff0c\u53ef\u8bfb\u6027\u8fdc\u4f18\u4e8e\u81ea\u5b9a\u4e49\u5224\u7a7a\u903b\u8f91\u3002<\/p>\n<\/blockquote>\n\n\n\n
    \u4e09\u3001\u975e\u7a7a\u6821\u9a8c\uff1arequireNonNull () \u53c2\u6570\u6821\u9a8c\u795e\u5668<\/h2>\n\n\n\n
    \u65b9\u6cd5\u5165\u53c2\u6821\u9a8c\u9996\u9009\uff0c\u5bf9\u8c61\u4e3a null \u76f4\u63a5\u629b\u51fa NPE\uff0c\u652f\u6301\u4e09\u79cd\u91cd\u8f7d\uff0c\u53ef\u81ea\u5b9a\u4e49\u5f02\u5e38\u63d0\u793a\u4fe1\u606f\uff0c\u591a\u7528\u4e8e\u63a5\u53e3\u3001\u5de5\u5177\u7c7b\u5165\u53c2\u9632\u5fa1\u6821\u9a8c\u3002<\/p>\n\n\n\n
      \n
    1. requireNonNull(T obj)<\/code>\uff1a\u7a7a\u5219\u629b\u9ed8\u8ba4 NPE<\/li>\n\n\n\n
    2. requireNonNull(T obj, String msg)<\/code>\uff1a\u7a7a\u5219\u629b\u643a\u5e26\u81ea\u5b9a\u4e49\u6587\u6848\u7684 NPE<\/li>\n\n\n\n
    3. requireNonNull(T obj, Supplier<String> msgSupplier)<\/code>\uff1alambda \u61d2\u52a0\u8f7d\u5f02\u5e38\u6587\u6848\uff0c\u7a7a\u65f6\u624d\u751f\u6210\u63d0\u793a\uff0c\u6027\u80fd\u66f4\u4f18<\/li>\n<\/ol>\n\n\n\n
      \u4ee3\u7801\u793a\u4f8b<\/h3>\n\n\n\n
      \/\/ \u6a21\u62df\u63a5\u53e3\u5165\u53c2\u6821\u9a8c\npublic static void checkParam(Integer userId){\n    \/\/ 1.\u9ed8\u8ba4\u5f02\u5e38\u4fe1\u606f\n    Integer id1 = Objects.requireNonNull(userId);\n\n    \/\/ 2.\u81ea\u5b9a\u4e49\u5f02\u5e38\u63d0\u793a\u5b57\u7b26\u4e32\n    Integer id2 = Objects.requireNonNull(userId, \"\u7528\u6237ID\u4e0d\u80fd\u4e3a\u7a7a\");\n\n    \/\/ 3.lambda\u52a8\u6001\u751f\u6210\u5f02\u5e38\u4fe1\u606f\uff08\u61d2\u52a0\u8f7d\uff0c\u53ea\u6709null\u624d\u6267\u884clambda\uff09\n    Integer id3 = Objects.requireNonNull(userId, () -> \"\u53c2\u6570\u5f02\u5e38\uff1a\u7528\u6237ID\u3010\"+userId+\"\u3011\u4e0d\u80fd\u4e3a\u7a7a\");\n}\n\n\/\/ \u6d4b\u8bd5\u8c03\u7528\npublic static void main(String[] args) {\n    Integer num = null;\n    checkParam(num); \/\/ \u89e6\u53d1\u7a7a\u6307\u9488\u5f02\u5e38\uff0c\u6253\u5370\u81ea\u5b9a\u4e49\u63d0\u793a\n}\n<\/code><\/pre>\n\n\n\n
      \n
      \u5b9e\u9645\u9879\u76ee\uff1aController\u3001Service \u5c42\u5165\u53c2\u6821\u9a8c\uff0c\u7528\u8fd9\u4e2a\u65b9\u6cd5\u66ff\u4ee3\u4e00\u5806 if \u5224\u7a7a\uff0c\u4ee3\u7801\u77ac\u95f4\u7cbe\u7b80\u3002<\/p>\n<\/blockquote>\n\n\n\n
      \u56db\u3001\u5b89\u5168\u76f8\u7b49\u5224\u65ad\uff1aObjects.equals ()<\/h2>\n\n\n\n
      \u539f\u751fa.equals(b)<\/code>\u5982\u679c a \u4e3a null\uff0c\u4f1a\u76f4\u63a5\u7a7a\u6307\u9488\u62a5\u9519\uff1bObjects.equals(a,b)<\/code>\u505a\u4e86\u7a7a\u503c\u517c\u5bb9\uff0c\u4e24\u8fb9\u4efb\u610f\u4e00\u65b9\u4e3a null \u90fd\u4e0d\u4f1a\u629b\u5f02\u5e38<\/strong>\uff0c\u5e95\u5c42\u5148\u505a\u5f15\u7528\u5730\u5740\u5224\u65ad\u518d\u8c03\u7528\u5bf9\u8c61\u81ea\u8eab equals \u65b9\u6cd5\u3002<\/p>\n\n\n\n
      \u4ee3\u7801\u793a\u4f8b<\/h3>\n\n\n\n
      public static void main(String[] args) {\n    String s1 = null;\n    String s2 = \"Java\";\n    String s3 = \"Java\";\n\n    \/\/ \u539f\u751f\u5199\u6cd5\u62a5\u9519\uff1as1.equals(s2) \u7a7a\u6307\u9488\n    \/\/ Objects\u5b89\u5168\u6bd4\u5bf9\n    System.out.println(Objects.equals(s1,s2)); \/\/ false\n    System.out.println(Objects.equals(s2,s3)); \/\/ true\n    System.out.println(Objects.equals(null,null)); \/\/ true\n}\n<\/code><\/pre>\n\n\n\n
      \n
      \u6ce8\u610f\uff1a\u6700\u7ec8\u76f8\u7b49\u903b\u8f91\u4f9d\u8d56\u5b9e\u4f53\u7c7b\u91cd\u5199\u7684equals()<\/code>\uff0c\u5982\u679c\u5b9e\u4f53\u6ca1\u6709\u91cd\u5199 equals\uff0c\u4f9d\u7136\u8d70 Object \u539f\u751f\u5730\u5740\u6bd4\u5bf9\u903b\u8f91\u3002<\/p>\n<\/blockquote>\n\n\n\n
      \u4e94\u3001\u83b7\u53d6\u54c8\u5e0c\u503c\uff1aObjects.hashCode ()<\/h2>\n\n\n\n
      \u5b89\u5168\u83b7\u53d6\u5bf9\u8c61 hashCode\uff0c\u5bf9\u8c61\u4e3a null \u65f6\u76f4\u63a5\u8fd4\u56de 0\uff0c\u4e0d\u4f1a\u89e6\u53d1\u7a7a\u6307\u9488\u3002<\/p>\n\n\n\n
      public static void main(String[] args) {\n    String str = null;\n    String blog = \"\u4e91\u626c\u306eBlog\";\n    System.out.println(Objects.hashCode(str));    \/\/ 0\n    System.out.println(Objects.hashCode(blog));    \/\/ \u5bf9\u5e94\u5b57\u7b26\u4e32\u54c8\u5e0c\u503c\n}\n<\/code><\/pre>\n\n\n\n
      \u62d3\u5c55\uff1aObjects.hash(\u5b57\u6bb51,\u5b57\u6bb52...)<\/code>\u53ef\u5feb\u901f\u751f\u6210\u591a\u5b57\u6bb5\u7ec4\u5408\u54c8\u5e0c\uff0c\u91cd\u5199\u5b9e\u4f53 hashCode \u5f88\u65b9\u4fbf\u3002<\/p>\n\n\n\n
      \u516d\u3001\u5bf9\u8c61\u6392\u5e8f\u6bd4\u8f83\uff1acompare ()<\/h2>\n\n\n\n
      \u914d\u5408Comparator<\/code>\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\uff0c\u591a\u7528\u4e8e\u81ea\u5b9a\u4e49\u6392\u5e8f\u573a\u666f\uff0c\u5165\u53c2\u6bd4\u8f83\u5668\u4e3a null \u65f6\u4f7f\u7528\u5bf9\u8c61\u81ea\u7136\u6392\u5e8f\u3002<\/p>\n\n\n\n
      class User{\n    Integer age;\n    User(Integer age){ this.age = age; }\n}\n\npublic static void main(String[] args) {\n    User u1 = new User(18);\n    User u2 = new User(22);\n    \/\/ \u6839\u636e\u5e74\u9f84\u5347\u5e8f\u6bd4\u8f83\n    int res = Objects.compare(u1, u2, Comparator.comparingInt(user -> user.age));\n    System.out.println(res); \/\/ -1\uff08u1\u5c0f\u4e8eu2\uff09\n}\n<\/code><\/pre>\n\n\n\n
      \u4e03\u3001\u6570\u7ec4\u6df1\u5ea6\u6bd4\u5bf9\uff1adeepEquals ()<\/h2>\n\n\n\n
      \u666e\u901aequals()<\/code>\u53ea\u80fd\u6bd4\u5bf9\u6570\u7ec4\u5730\u5740\uff0cdeepEquals()<\/code>\u652f\u6301\u591a\u7ef4\u6570\u7ec4\u3001\u5143\u7d20\u9012\u5f52\u6df1\u5ea6\u6bd4\u5bf9\uff0c\u975e\u6570\u7ec4\u5bf9\u8c61\u7528\u6cd5\u548cObjects.equals()<\/code>\u4e00\u81f4\u3002<\/p>\n\n\n\n
      public static void main(String[] args) {\n    String[] arr1 = {\"Java\",\"MySQL\"};\n    String[] arr2 = {\"Java\",\"MySQL\"};\n    String[][] arr3 = {{\"A\"},{\"B\"}};\n    String[][] arr4 = {{\"A\"},{\"B\"}};\n\n    System.out.println(Objects.deepEquals(arr1,arr2));  \/\/ true\n    System.out.println(Objects.deepEquals(arr3,arr4));  \/\/ true\n}\n<\/code><\/pre>\n\n\n\n
      \u6587\u672b\u5c0f\u7ed3<\/h2>\n\n\n\n
        \n
      1. isNull\/nonNull<\/code>\uff1a\u65e5\u5e38\u7a7a\u503c\u5224\u65ad\uff0c\u89c4\u8303\u4ee3\u7801\uff1b<\/li>\n\n\n\n
      2. requireNonNull<\/code>\uff1a\u53c2\u6570\u6821\u9a8c\u6807\u914d\uff0c\u5feb\u901f\u629b\u51fa\u975e\u6cd5\u5165\u53c2\u5f02\u5e38\uff1b<\/li>\n\n\n\n
      3. equals\/deepEquals<\/code>\uff1a\u89c4\u907f\u7a7a\u6307\u9488\u7684\u5b89\u5168\u6bd4\u5bf9\uff0c\u666e\u901a\u5bf9\u8c61 \/ \u6570\u7ec4\u5206\u5f00\u9009\u7528\uff1b<\/li>\n\n\n\n
      4. hashCode\/compare<\/code>\uff1a\u7b80\u5316\u54c8\u5e0c\u751f\u6210\u4e0e\u81ea\u5b9a\u4e49\u6392\u5e8f\u3002<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"
        \u5927\u5bb6\u597d\uff0c\u6211\u662f\u4e91\u626c\u3002\u65e5\u5e38 Java \u5f00\u53d1\u91cc\uff0c\u7a7a\u6307\u9488\u5f02\u5e38\uff08NullPointerException\uff09 \u7edd\u5bf9\u662f\u9ad8\u9891\u8e29<\/p>\n
        \n\t\t\t\t Read More <\/span> <\/i><\/a>\n\t\t\t<\/div>\n","protected":false},"author":1,"featured_media":1582,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[15],"class_list":["post-1581","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java","tag-java"],"_links":{"self":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1581","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1581"}],"version-history":[{"count":2,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1581\/revisions"}],"predecessor-version":[{"id":1584,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/1581\/revisions\/1584"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/media\/1582"}],"wp:attachment":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1581"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1581"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1581"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}