{"id":112,"date":"2025-12-12T01:37:22","date_gmt":"2025-12-11T17:37:22","guid":{"rendered":"https:\/\/www.itcainiao.space\/?p=112"},"modified":"2025-12-12T01:55:08","modified_gmt":"2025-12-11T17:55:08","slug":"parental-delegation-model-26amj9","status":"publish","type":"post","link":"https:\/\/www.itcainiao.space\/index.php\/2025\/12\/12\/parental-delegation-model-26amj9\/","title":{"rendered":"\u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b"},"content":{"rendered":"

\u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b<\/h1>\n

\u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b\uff08Parent Delegation Model\uff09\u662f Java \u7c7b\u52a0\u8f7d\u5668\uff08ClassLoader\uff09\u7684\u6838\u5fc3\u8bbe\u8ba1\u6a21\u5f0f\uff0c\u7528\u4e8e\u200b\u4fdd\u8bc1\u7c7b\u52a0\u8f7d\u7684\u5b89\u5168\u6027\u548c\u552f\u4e00\u6027<\/strong>\uff0c\u907f\u514d\u7c7b\u91cd\u590d\u52a0\u8f7d\u548c\u6838\u5fc3\u7c7b\u88ab\u7be1\u6539\u3002<\/p>\n

\u4e00\u3001\u6838\u5fc3\u539f\u7406<\/h3>\n

\u5f53\u4e00\u4e2a\u7c7b\u52a0\u8f7d\u5668\u6536\u5230\u7c7b\u52a0\u8f7d\u8bf7\u6c42\u65f6\uff0c\u5b83\u4e0d\u4f1a\u7acb\u5373\u81ea\u5df1\u52a0\u8f7d\uff0c\u800c\u662f\u200b\u5148\u59d4\u6d3e\u7ed9\u7236\u7c7b\u52a0\u8f7d\u5668<\/strong>\uff0c\u9010\u5c42\u5411\u4e0a\u4f20\u9012\u8bf7\u6c42\uff1b\u53ea\u6709\u5f53\u7236\u7c7b\u52a0\u8f7d\u5668\u65e0\u6cd5\u52a0\u8f7d\u8be5\u7c7b\uff08\u5728\u5176\u641c\u7d22\u8303\u56f4\u5185\u627e\u4e0d\u5230\uff09\u65f6\uff0c\u5b50\u7c7b\u52a0\u8f7d\u5668\u624d\u4f1a\u5c1d\u8bd5\u81ea\u5df1\u52a0\u8f7d\u3002<\/p>\n

\u7b80\u5355\u6765\u8bf4\uff1a\u200b\u5148\u627e\u7239\uff0c\u7239\u4e0d\u884c\uff0c\u81ea\u5df1\u4e0a<\/strong>\u3002<\/p>\n

\u4e8c\u3001\u7c7b\u52a0\u8f7d\u5668\u5c42\u7ea7\u7ed3\u6784<\/h3>\n

Java \u4e2d\u7684\u7c7b\u52a0\u8f7d\u5668\u6309\u5c42\u7ea7\u4ece\u4e0a\u5230\u4e0b\u5206\u4e3a\uff1a<\/p>\n

    \n
  1. \n

    \u542f\u52a8\u7c7b\u52a0\u8f7d\u5668\uff08Bootstrap ClassLoader\uff09<\/strong><\/p>\n

      \n
    • \u6700\u9876\u5c42\uff0c\u7531 C++ \u5b9e\u73b0\uff08\u975e Java \u7c7b\uff09\uff0c\u8d1f\u8d23\u52a0\u8f7d$JAVA_HOME\/jre\/lib\/rt.jar<\/code>\u200b\uff08\u6838\u5fc3\u7c7b\u5e93\uff0c\u5982java.lang.String<\/code>\uff09\u3002<\/li>\n
    • \u65e0\u7236\u7c7b\u52a0\u8f7d\u5668\uff0c\u4e5f\u65e0\u6cd5\u901a\u8fc7 Java \u4ee3\u7801\u76f4\u63a5\u5f15\u7528\u3002<\/li>\n<\/ul>\n<\/li>\n
    • \n

      \u6269\u5c55\u7c7b\u52a0\u8f7d\u5668\uff08Extension ClassLoader\uff09<\/strong><\/p>\n

        \n
      • \u7236\u7c7b\u662f\u542f\u52a8\u7c7b\u52a0\u8f7d\u5668\uff0c\u8d1f\u8d23\u52a0\u8f7d$JAVA_HOME\/jre\/lib\/ext\/*.jar<\/code>\uff08\u6269\u5c55\u7c7b\u5e93\uff09\u3002<\/li>\n
      • \u7531sun.misc.Launcher$ExtClassLoader<\/code>\u5b9e\u73b0\u3002<\/li>\n<\/ul>\n<\/li>\n
      • \n

        \u5e94\u7528\u7a0b\u5e8f\u7c7b\u52a0\u8f7d\u5668\uff08Application ClassLoader\uff09<\/strong><\/p>\n

          \n
        • \u7236\u7c7b\u662f\u6269\u5c55\u7c7b\u52a0\u8f7d\u5668\uff0c\u8d1f\u8d23\u52a0\u8f7d\u7528\u6237\u7c7b\u8def\u5f84\uff08ClassPath<\/code>\uff09\u4e0b\u7684\u7c7b\uff08\u9879\u76ee\u4ee3\u7801\u3001\u7b2c\u4e09\u65b9\u4f9d\u8d56\uff09\u3002<\/li>\n
        • \u7531sun.misc.Launcher$AppClassLoader<\/code>\u5b9e\u73b0\uff0c\u4e5f\u662f\u9ed8\u8ba4\u7684\u7cfb\u7edf\u7c7b\u52a0\u8f7d\u5668\u3002<\/li>\n<\/ul>\n<\/li>\n
        • \n

          \u81ea\u5b9a\u4e49\u7c7b\u52a0\u8f7d\u5668\uff08Custom ClassLoader\uff09<\/strong><\/p>\n

            \n
          • \u5f00\u53d1\u8005\u7ee7\u627fjava.lang.ClassLoader<\/code>\u5b9e\u73b0\uff0c\u7528\u4e8e\u52a0\u8f7d\u81ea\u5b9a\u4e49\u8def\u5f84\u7684\u7c7b\uff08\u5982 Tomcat \u7684 WebAppClassLoader\uff09\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

            \u4e09\u3001\u5de5\u4f5c\u6d41\u7a0b<\/h3>\n

            \u4ee5\u52a0\u8f7dcom.example.Test<\/code>\u7c7b\u4e3a\u4f8b\uff1a<\/p>\n

              \n
            1. \u5e94\u7528\u7a0b\u5e8f\u7c7b\u52a0\u8f7d\u5668<\/strong>\u6536\u5230\u8bf7\u6c42\uff0c\u5148\u59d4\u6d3e\u7ed9\u7236\u7c7b\u200b\u6269\u5c55\u7c7b\u52a0\u8f7d\u5668<\/strong>\u3002<\/li>\n
            2. \u6269\u5c55\u7c7b\u52a0\u8f7d\u5668<\/strong>\u518d\u59d4\u6d3e\u7ed9\u7236\u7c7b\u200b\u542f\u52a8\u7c7b\u52a0\u8f7d\u5668<\/strong>\u3002<\/li>\n
            3. \u542f\u52a8\u7c7b\u52a0\u8f7d\u5668<\/strong>\u68c0\u67e5\u6838\u5fc3\u7c7b\u5e93\uff0c\u53d1\u73b0\u6ca1\u6709com.example.Test<\/code>\uff0c\u8fd4\u56de \u201c\u65e0\u6cd5\u52a0\u8f7d\u201d\u3002<\/li>\n
            4. \u6269\u5c55\u7c7b\u52a0\u8f7d\u5668<\/strong>\u68c0\u67e5\u6269\u5c55\u7c7b\u5e93\uff0c\u4e5f\u6ca1\u6709\uff0c\u8fd4\u56de \u201c\u65e0\u6cd5\u52a0\u8f7d\u201d\u3002<\/li>\n
            5. \u5e94\u7528\u7a0b\u5e8f\u7c7b\u52a0\u8f7d\u5668<\/strong>\u5728ClassPath<\/code>\u200b\u4e0b\u67e5\u627e\u5e76\u52a0\u8f7dcom.example.Test<\/code>\u7c7b\u3002<\/li>\n<\/ol>\n

              \u56db\u3001\u4f18\u52bf<\/h3>\n
                \n
              1. \u200b\u5b89\u5168\u6027<\/strong>\u200b\uff1a\u6838\u5fc3\u7c7b\uff08\u5982java.lang.String<\/code>\uff09\u53ea\u80fd\u7531\u542f\u52a8\u7c7b\u52a0\u8f7d\u5668\u52a0\u8f7d\uff0c\u907f\u514d\u7528\u6237\u81ea\u5b9a\u4e49\u540c\u540d\u7c7b\u7be1\u6539\u6838\u5fc3 API\uff08\u9632\u6b62 \u201cString \u7c7b\u88ab\u66ff\u6362\u201d \u7b49\u5b89\u5168\u95ee\u9898\uff09\u3002<\/li>\n
              2. \u200b\u552f\u4e00\u6027<\/strong>\uff1a\u540c\u4e00\u4e2a\u7c7b\u53ea\u4f1a\u88ab\u52a0\u8f7d\u4e00\u6b21\uff08\u7531\u6700\u9876\u5c42\u7684\u7c7b\u52a0\u8f7d\u5668\u52a0\u8f7d\uff09\uff0c\u4fdd\u8bc1\u7c7b\u7684\u5168\u5c40\u552f\u4e00\u6027\u3002<\/li>\n
              3. \u200b\u5c42\u7ea7\u9694\u79bb<\/strong>\uff1a\u4e0d\u540c\u5c42\u7ea7\u7684\u7c7b\u52a0\u8f7d\u5668\u8d1f\u8d23\u4e0d\u540c\u8303\u56f4\u7684\u7c7b\uff0c\u907f\u514d\u7c7b\u51b2\u7a81\u3002<\/li>\n<\/ol>\n

                \u4e94\u3001\u6253\u7834\u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b\u7684\u573a\u666f<\/h3>\n

                \u5e76\u975e\u6240\u6709\u573a\u666f\u90fd\u4e25\u683c\u9075\u5faa\u53cc\u4eb2\u59d4\u6d3e\uff0c\u4ee5\u4e0b\u60c5\u51b5\u4f1a \u201c\u53cd\u5411\u59d4\u6d3e\u201d \u6216\u76f4\u63a5\u52a0\u8f7d\uff1a<\/p>\n

                  \n
                1. SPI \u673a\u5236\uff08Service Provider Interface\uff09<\/strong> \u4f8b\u5982 JDBC \u9a71\u52a8\uff08java.sql.Driver<\/code>\u200b\uff09\uff1a\u6838\u5fc3\u7c7bDriver<\/code>\u200b\u7531\u542f\u52a8\u7c7b\u52a0\u8f7d\u5668\u52a0\u8f7d\uff0c\u4f46\u5177\u4f53\u9a71\u52a8\u5b9e\u73b0\uff08\u5982 MySQL \u9a71\u52a8\uff09\u5728ClassPath<\/code>\u200b\u4e0b\uff0c\u9700\u7531\u5e94\u7528\u7a0b\u5e8f\u7c7b\u52a0\u8f7d\u5668\u52a0\u8f7d \u2192 \u542f\u52a8\u7c7b\u52a0\u8f7d\u5668\u4f1a\u59d4\u6d3e\u5b50\u7c7b\u52a0\u8f7d\u5668\u52a0\u8f7d\uff08\u7ebf\u7a0b\u4e0a\u4e0b\u6587\u7c7b\u52a0\u8f7d\u5668<\/strong>\u5b9e\u73b0\uff09\u3002<\/li>\n
                2. Tomcat \u7b49\u5bb9\u5668<\/strong>Tomcat \u4e3a\u6bcf\u4e2a Web \u5e94\u7528\u521b\u5efa\u72ec\u7acb\u7684\u7c7b\u52a0\u8f7d\u5668\uff08WebAppClassLoader\uff09\uff0c\u4f18\u5148\u52a0\u8f7d\u5e94\u7528\u5185\u7684\u7c7b\uff08\u800c\u975e\u59d4\u6d3e\u7236\u7c7b\uff09\uff0c\u907f\u514d\u4e0d\u540c\u5e94\u7528\u7684\u7c7b\u51b2\u7a81\u3002<\/li>\n
                3. \u70ed\u90e8\u7f72 \/ \u52a8\u6001\u52a0\u8f7d<\/strong>\u81ea\u5b9a\u4e49\u7c7b\u52a0\u8f7d\u5668\u9700\u5b9e\u65f6\u52a0\u8f7d\u65b0\u7c7b\uff0c\u53ef\u80fd\u7ed5\u8fc7\u53cc\u4eb2\u59d4\u6d3e\u76f4\u63a5\u52a0\u8f7d\u3002<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

                  \u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b \u53cc\u4eb2\u59d4\u6d3e\u6a21\u578b\uff08Parent Delegation Model\uff09\u662f Java \u7c7b\u52a0\u8f7d\u5668\uff08Class […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-112","post","type-post","status-publish","format-standard","hentry","category-javajishu"],"_links":{"self":[{"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/posts\/112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/comments?post=112"}],"version-history":[{"count":4,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/posts\/112\/revisions"}],"predecessor-version":[{"id":116,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/posts\/112\/revisions\/116"}],"wp:attachment":[{"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/media?parent=112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/categories?post=112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.itcainiao.space\/index.php\/wp-json\/wp\/v2\/tags?post=112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}