{"id":10020841,"date":"2025-06-23T17:00:26","date_gmt":"2025-06-23T09:00:26","guid":{"rendered":"https:\/\/itmax.cn\/?p=10020841"},"modified":"2025-06-23T17:00:26","modified_gmt":"2025-06-23T09:00:26","slug":"jdk%e9%ab%98%e7%89%88%e6%9c%ac%e7%89%b9%e6%80%a7%e6%80%bb%e7%bb%93%e4%b8%8ezgc%e5%ae%9e%e8%b7%b5","status":"publish","type":"post","link":"https:\/\/itmax.cn\/?p=10020841","title":{"rendered":"JDK\u9ad8\u7248\u672c\u7279\u6027\u603b\u7ed3\u4e0eZGC\u5b9e\u8df5"},"content":{"rendered":"

\u7f8e\u56e2\u4fe1\u606f\u5b89\u5168\u6280\u672f\u56e2\u961f\u6838\u5fc3\u670d\u52a1\u5347\u7ea7JDK 17\u540e\uff0c\u6027\u80fd\u4e0e\u7a33\u5b9a\u6027\u5927\u5e45\u63d0\u5347\uff0c\u673a\u5668\u6210\u672c\u964d\u4f4e\u4e8610%\u3002\u9ad8\u7248\u672cJDK\u4e0eZGC\u6280\u672f\u4ee4\u4eba\u60ca\u8273\uff0c\u4e14Java AI SDK\u6700\u4f4e\u652f\u6301JDK 17\u3002\u672c\u6587\u603b\u7ed3\u4e86JDK 17\u7684\u4e3b\u8981\u7279\u6027\uff0c\u7136\u540e\u91cd\u70b9\u5206\u4eab\u4e86JDK 17+ZGC\u5728\u5b89\u5168\u9886\u57df\u7684\u4e00\u4e9b\u5b9e\u8df5\uff0c\u5e0c\u671b\u80fd\u5bf9\u5927\u5bb6\u6709\u6240\u5e2e\u52a9\u6216\u542f\u53d1\u3002<\/p><\/blockquote>\n

\u4ece\u4e00\u53e5\u8c03\u4f83\u7684\u8bdd \u201c\u4f60\u53d1\u4efb\u4f60\u53d1\uff0c\u6211\u7528Java 8\uff01\u201d \u53ef\u4ee5\u770b\u51fa\uff0c\u5728\u5f00\u53d1\u65b0\u9879\u76ee\u65f6\uff0cJava 8\u4f9d\u7136\u662f\u5927\u5bb6\u7684\u9996\u9009\u3002\u7f8e\u56e2Java 8\u670d\u52a1\u5360\u6bd4\u8d85\u8fc770%\uff0c\u53ef\u4ee5\u8bf4Java 8\u4f9d\u7136\u662f\u7edd\u5bf9\u7684\u4e3b\u6d41\u3002\u4f46\u662f\uff0c\u6211\u4eec\u5728\u591a\u4e2a\u6838\u5fc3\u670d\u52a1\u4e0a\u9047\u5230\u8f83\u591a\u7684\u6027\u80fd\u95ee\u9898\uff0c\u8fd9\u4e9b\u95ee\u9898\u65e0\u6cd5\u901a\u8fc7JVM\u53c2\u6570\u5fae\u8c03\u6765\u89e3\u51b3\uff0c\u4e3a\u6b64\u6211\u4eec\u5bf9\u90e8\u5206\u6838\u5fc3\u670d\u52a1\u4f7f\u7528\u4e86 JDK 17\uff0c\u5347\u7ea7\u540e\u670d\u52a1\u6027\u80fd\u548c\u7a33\u5b9a\u6027\u6307\u6807\u4e5f\u5f97\u5230\u5de8\u5927\u7684\u98de\u8dc3\uff0c\u540c\u65f6\u673a\u5668\u6210\u672c\u53ef\u4ee5\u4e0b\u964d\u7ea610%\uff0c\u5347\u7ea7JDK\u7248\u672c\u6536\u76ca\u5341\u5206\u660e\u663e\u3002\u53e6\u5916\uff0c\u76ee\u524d\u6b63\u5904\u5728AI\u65f6\u4ee3\u7684\u7206\u53d1\u671f\uff0cJava AI SDK\u7684\u6700\u5c0f\u652f\u6301\u7248\u672c\u4e3aJDK 17\uff0c\u8fd9\u8ba9\u5347\u7ea7JDK\u7248\u672c\u53d8\u5f97\u66f4\u5177\u4ef7\u503c\u3002\u63a5\u4e0b\u6765\uff0c\u671f\u671b\u8ddf\u5927\u5bb6\u4e00\u8d77\u63a2\u7d22JDK\u9ad8\u7248\u672c\u548cZGC\u6280\u672f\u7684\u5965\u79d8\uff0c\u5f00\u542f\u4f18\u5316Java\u5e94\u7528\u7684\u65b0\u5f81\u7a0b\u3002<\/p>\n

1. JDK 17\u7684\u4e3b\u8981\u7279\u6027<\/h2>\n

\u5305\u542bJDK 9~17\u7b49\u4e2d\u95f4\u7248\u672c\u7684\u7279\u6027\u3002<\/p><\/blockquote>\n

\u4ece JDK 8 \u76f4\u63a5\u5347\u7ea7\u5230 JDK 17\uff0c\u4ee5\u4e0b\u662f\u9700\u8981\u91cd\u70b9\u5173\u6ce8\u7684\u7279\u6027\uff0c\u8fd9\u4e9b\u7279\u6027\u5bf9\u5f00\u53d1\u6548\u7387\u3001\u4ee3\u7801\u98ce\u683c\u3001\u6027\u80fd\u4f18\u5316\u548c\u5b89\u5168\u6027\u90fd\u6709\u663e\u8457\u5f71\u54cd\u3002<\/p>\n

1.1 \u8bed\u8a00\u7279\u6027[1]<\/sup><\/h3>\n

1.1.1 \u5c40\u90e8\u53d8\u91cf\u7c7b\u578b\u63a8\u65ad<\/h4>\n

\u4f7f\u7528var\u5173\u952e\u5b57\u6765\u58f0\u660e\u5c40\u90e8\u53d8\u91cf\uff0c\u800c\u65e0\u9700\u663e\u5f0f\u6307\u5b9a\u53d8\u91cf\u7684\u7c7b\u578b\u3002\u5728Java 17\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u5c40\u90e8\u53d8\u91cf\u7c7b\u578b\u63a8\u65ad\u7684\u6269\u5c55\u6765\u7f16\u5199\u66f4\u7b80\u6d01\u7684\u4ee3\u7801\u3002\u5176\u4ed6\u8bed\u8a00\u5982Golang\u5f88\u65e9\u5c31\u652f\u6301\u4e86var\u53d8\u91cf\u3002<\/p>\n

\/\/ JDK8\nString str = "Hello world";\n\n\/\/ JDK17\nvar str = "Hello world";<\/code><\/pre>\n
\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0cvar\u7c7b\u578b\u7684\u5c40\u90e8\u53d8\u91cf\u4ecd\u7136\u5177\u6709\u9759\u6001\u7c7b\u578b\uff0c\u4e00\u65e6\u88ab\u63a8\u65ad\u51fa\u6765\uff0c\u7c7b\u578b\u5c31\u4f1a\u56fa\u5b9a\u4e0b\u6765\uff0c\u5e76\u4e14\u4e0d\u80fd\u91cd\u65b0\u8d4b\u503c\u4e3a\u4e0d\u517c\u5bb9\u7684\u7c7b\u578b\u3002<\/p><\/blockquote>\n
1.1.2 \u5bc6\u5c01\u7c7b<\/h4>\n
\u5b83\u5141\u8bb8\u6211\u4eec\u5c06\u7c7b\u6216\u63a5\u53e3\u7684\u7ee7\u627f\u9650\u5236\u4e3a\u4e00\u7ec4\u6709\u9650\u7684\u5b50\u7c7b\u3002\u5982\u679c\u60f3\u5c06\u7c7b\u6216\u63a5\u53e3\u7684\u7ee7\u627f\u9650\u5236\u4e3a\u4e00\u7ec4\u6709\u9650\u7684\u5b50\u7c7b\u65f6\uff0c\u8fd9\u975e\u5e38\u6709\u7528\u3002\u5728\u4e0b\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u53ef\u4ee5\u770b\u5230\u6211\u4eec\u5982\u4f55\u4f7f\u7528sealed\u5173\u952e\u5b57\u5c06\u7c7b\u7684\u7ee7\u627f\u9650\u5236\u4e3a\u4e00\u7ec4\u6709\u9650\u7684\u5b50\u7c7b\u3002\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5728\u7c7b\u7684\u58f0\u660e\u524d\u52a0\u4e0asealed\u5173\u952e\u5b57\u6765\u5c06\u8be5\u7c7b\u58f0\u660e\u4e3a\u5bc6\u5c01\u7c7b\u3002\u7136\u540e\uff0c\u53ef\u4ee5\u4f7f\u7528permits\u5173\u952e\u5b57\u5217\u51fa\u8be5\u5bc6\u5c01\u7c7b\u5141\u8bb8\u7ee7\u627f\u7684\u5b50\u7c7b\u3002\u8fd9\u4e9b\u5b50\u7c7b\u5fc5\u987b\u76f4\u63a5\u6216\u95f4\u63a5\u5730\u7ee7\u627f\u81ea\u5bc6\u5c01\u7c7b\u3002\u8fd9\u6837\uff0c\u53ea\u6709\u5728\u8fd9\u4e2a\u9884\u5b9a\u4e49\u7684\u5b50\u7c7b\u4e2d\uff0c\u624d\u80fd\u7ee7\u627f\u8be5\u5bc6\u5c01\u7c7b\u3002<\/p>\n
\/\/\u4f7f\u7528permits\u5173\u952e\u5b57\u5217\u51fa\u4e86\u5141\u8bb8\u7ee7\u627f\u7684\u5b50\u7c7bCircle\u3001Rectangle\u548cTriangle\npublic sealed class Shape permits Circle, Rectangle, Triangle {\n    \/\/ \u7701\u7565\u5b9e\u73b0\n}\n\n\/\/ \u5728\u4e0e\u5bc6\u5c01\u7c7b\u76f8\u540c\u7684\u6a21\u5757\u6216\u5305\u4e2d \u5b9a\u4e49\u4ee5\u4e0b\u4e09\u4e2a\u5141\u8bb8\u7684\u5b50\u7c7b\uff0c Circle\uff0cSquare\u548c\uff1aRectangle\npublic final class Circle extends Shape {\n    public float radius;\n}\n \npublic non-sealed class Square extends Shape {\n   public double side;\n}   \n \npublic sealed class Rectangle extends Shape permits FilledRectangle {\n    public double length, width;\n}<\/code><\/pre>\n
1.1.3 Record \u7c7b<\/h4>\n
Record \u7c7b\u7684\u4e3b\u8981\u76ee\u7684\u662f\u63d0\u4f9b\u4e00\u79cd\u66f4\u7b80\u6d01\u3001\u66f4\u5b89\u5168\u7684\u65b9\u5f0f\u6765\u5b9a\u4e49\u4e0d\u53ef\u53d8\u7684\u6570\u636e\u8f7d\u4f53\u7c7b\u3002\u5b83\u81ea\u52a8\u5b9e\u73b0\u4e86\u5e38\u89c1\u7684\u65b9\u6cd5\uff08\u5982equals()<\/code>\u3001hashCode()<\/code>\u3001toString()<\/code>\u548c\u6784\u9020\u51fd\u6570\uff09\uff0c\u4ece\u800c\u51cf\u5c11\u4e86\u6837\u677f\u4ee3\u7801\u3002<\/p>\n
\u7279\u70b9<\/strong><\/p>\n
    \n
  1. \u4e0d\u53ef\u53d8\u6027<\/strong>\uff1aRecord\u7c7b\u7684\u5b57\u6bb5\u9ed8\u8ba4\u662ffinal<\/code>\u7684\uff0c\u56e0\u6b64 Record \u7c7b\u662f\u4e0d\u53ef\u53d8\u7684\u3002<\/li>\n
  2. \u7b80\u6d01\u6027<\/strong>\uff1aRecord\u7c7b\u81ea\u52a8\u63d0\u4f9b\u4e86\u6784\u9020\u51fd\u6570\u3001equals()<\/code>\u3001hashCode()<\/code>\u548ctoString()<\/code>\u65b9\u6cd5\uff0c\u65e0\u9700\u624b\u52a8\u7f16\u5199\u3002<\/li>\n
  3. \u7ec4\u4ef6\u8bbf\u95ee<\/strong>\uff1aRecord\u7c7b\u7684\u5b57\u6bb5\u53ef\u4ee5\u901a\u8fc7recordName.fieldName<\/code>\u7684\u65b9\u5f0f\u76f4\u63a5\u8bbf\u95ee\u3002<\/li>\n
  4. \u6a21\u5f0f\u5339\u914d<\/strong>\uff1aRecord\u7c7b\u652f\u6301\u6a21\u5f0f\u5339\u914d\uff08Pattern Matching\uff09\uff0c\u53ef\u4ee5\u4e0einstanceof<\/code>\u548cswitch<\/code>\u8868\u8fbe\u5f0f\u7ed3\u5408\u4f7f\u7528\u3002<\/li>\n<\/ol>\n
    Record\u7c7b\u7684\u5b9a\u4e49\u975e\u5e38\u7b80\u5355\uff0c\u53ea\u9700\u8981\u4f7f\u7528record<\/code>\u5173\u952e\u5b57\uff0c\u5e76\u58f0\u660e\u5b57\u6bb5\u7c7b\u578b\u548c\u540d\u79f0\u5373\u53ef\u3002\u4f8b\u5982\uff1a<\/p>\n
    \/\/ \u8fd9\u91cc\u6709\u4e00\u4e2a\u5305\u542b\u4e24\u4e2a\u5b57\u6bb5\u7684\u8bb0\u5f55\u7c7b\nrecord Rectangle(double length, double width) { }\n\n\/\/ \u8fd9\u4e2a\u7b80\u6d01\u7684\u77e9\u5f62\u58f0\u660e\u7b49\u540c\u4e8e\u4ee5\u4e0b\u666e\u901a\u7c7b\npublic final class Rectangle {\n    private final double length;\n    private final double width;\n\n    public Rectangle(double length, double width) {\n        this.length = length;\n        this.width = width;\n    }\n\n    double length() { return this.length; }\n    double width()  { return this.width; }\n\n    \/\/ ...\n    public boolean equals...\n    public int hashCode...\n\n    \/\/ ...\n    public String toString() {...}\n}<\/code><\/pre>\n
    1.1.4 switch\u8868\u8fbe\u5f0f\u4f18\u5316<\/h4>\n
    \u5728Java 17\u4e2d\u4f7f\u7528switch\u8868\u8fbe\u5f0f\u65f6\uff0c\u4e0d\u5fc5\u4f7f\u7528\u5173\u952e\u5b57break\u6765\u8df3\u51faswitch\u8bed\u53e5\uff0c\u6216return\u5728\u6bcf\u4e2aswitch case\u4e0a\u4f7f\u7528\u5173\u952e\u5b57\u6765\u8fd4\u56de\u503c\uff1b\u76f8\u53cd\uff0c\u6211\u4eec\u53ef\u4ee5\u8fd4\u56de\u6574\u4e2aswitch\u8868\u8fbe\u5f0f\u3002\u8fd9\u79cd\u589e\u5f3a\u7684switch\u8868\u8fbe\u5f0f\u4f7f\u6574\u4f53\u4ee3\u7801\u770b\u8d77\u6765\u66f4\u6e05\u6670\uff0c\u66f4\u6613\u4e8e\u9605\u8bfb\u3002switch\u6253\u5370\u4e00\u5468\u4e2d\u67d0\u4e00\u5929\u7684\u5b57\u6bcd\u6570\u91cf\u7684\u8bed\u53e5\u3002<\/p>\n
    JDK 8<\/strong><\/p>\n
    public enum Day { SUNDAY, MONDAY, TUESDAY,\n    WEDNESDAY, THURSDAY, FRIDAY, SATURDAY; }\n\n        \/\/ ...\n\n    int numLetters = 0;\n    Day day = Day.WEDNESDAY;\n    switch (day) {\n        case MONDAY:\n        case FRIDAY:\n        case SUNDAY:\n            numLetters = 6;\n            break;\n        case TUESDAY:\n            numLetters = 7;\n            break;\n        case THURSDAY:\n        case SATURDAY:\n            numLetters = 8;\n            break;\n        case WEDNESDAY:\n            numLetters = 9;\n            break;\n        default:\n            throw new IllegalStateException("Invalid day: " + day);\n    }\n    System.out.println(numLetters);<\/code><\/pre>\n
    JDK 17<\/strong><\/p>\n
            Day day = Day.WEDNESDAY;    \n    System.out.println(\n        switch (day) {\n            case MONDAY, FRIDAY, SUNDAY -> 6;\n            case TUESDAY                -> 7;\n            case THURSDAY, SATURDAY     -> 8;\n            case WEDNESDAY              -> 9;\n            default -> throw new IllegalStateException("Invalid day: " + day);\n        }\n    ); <\/code><\/pre>\n
    1.1.5 \u6587\u672c\u5757<\/h4>\n
    \u5728\u4e0d\u4f7f\u7528\u8f6c\u4e49\u5e8f\u5217\u7684\u60c5\u51b5\u4e0b\u521b\u5efa\u591a\u884c\u5b57\u7b26\u4e32\u3002\u5728\u521b\u5efaSQL\u67e5\u8be2\u6216JSON\u5b57\u7b26\u4e32\u65f6\u975e\u5e38\u6709\u7528\u3002\u5728\u4e0b\u9762\u7684\u793a\u4f8b\u4e2d\uff0c\u53ef\u4ee5\u770b\u5230\u4f7f\u7528\u6587\u672c\u5757\u65f6\u4ee3\u7801\u770b\u8d77\u6765\u66f4\u52a0\u7b80\u6d01\u3002<\/p>\n
    \/\/ JDK8\nString message = "'The time has come,' the Walrus said,\/n" +\n                 "'To talk of many things:\/n" +\n                 "Of shoes -- and ships -- and sealing-wax --\/n" +\n                 "Of cabbages -- and kings --\/n" +\n                 "And why the sea is boiling hot --\/n" +\n                 "And whether pigs have wings.'\/n";\n\n\/\/ \u4f7f\u7528\u6587\u672c\u5757\u53ef\u4ee5\u6d88\u9664\u5927\u90e8\u5206\u6df7\u4e71\uff1a\nString message = """\n    'The time has come,' the Walrus said,\n    'To talk of many things:\n    Of shoes -- and ships -- and sealing-wax --\n    Of cabbages -- and kings --\n    And why the sea is boiling hot --\n    And whether pigs have wings.'\n    """;<\/code><\/pre>\n
    SQL\u6ce8\u89e3\u63cf\u8ff0<\/strong><\/p>\n
    \/\/ JDK8    \n@Select("select distinct ta.host_name from tb_agent_info tai, tb_agent ta where 1=1 " +\n        "and ta.host_name=tai.host_name and ta.status=1 and ta.master=1 and tai.report_pid_count > 0")\nSet<String> queryAllJavaHost();\n\n\/\/ JDK17\n@Select("""\n    SELECT DISTINCT ta.host_name\n    FROM tb_agent_info tai, tb_agent ta\n    WHERE 1=1\n      AND ta.host_name = tai.host_name\n      AND ta.status = 1\n      AND ta.master = 1\n      AND tai.report_pid_count > 0\n """)\n Set<String> queryAllJavaHost2();<\/code><\/pre>\n