{"id":2208,"date":"2025-03-02T10:28:49","date_gmt":"2025-03-02T02:28:49","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=2208"},"modified":"2025-03-02T10:28:49","modified_gmt":"2025-03-02T02:28:49","slug":"java-stringbuffer-%e5%92%8c-stringbuilder-%e7%b1%bb","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/03\/02\/java-stringbuffer-%e5%92%8c-stringbuilder-%e7%b1%bb\/","title":{"rendered":"Java StringBuffer \u548c StringBuilder \u7c7b"},"content":{"rendered":"\n

StringBuffer<\/code> \u548c StringBuilder<\/code> \u7c7b\u662f Java \u4e2d\u7528\u4e8e\u5904\u7406\u53ef\u53d8\u5b57\u7b26\u4e32\u7684\u7c7b\uff0c\u5b83\u4eec\u63d0\u4f9b\u4e86\u6bd4 String<\/code> \u66f4\u9ad8\u6548\u7684\u5b57\u7b26\u4e32\u62fc\u63a5\u64cd\u4f5c\u3002\u4e0e String<\/code> \u7c7b\u4e0d\u540c\uff0cStringBuffer<\/code> \u548c StringBuilder<\/code> \u5141\u8bb8\u76f4\u63a5\u4fee\u6539\u5176\u5185\u5bb9\uff0c\u800c\u4e0d\u9700\u8981\u521b\u5efa\u65b0\u7684\u5bf9\u8c61\u3002\u56e0\u6b64\uff0c\u5b83\u4eec\u5728\u8fdb\u884c\u5927\u91cf\u5b57\u7b26\u4e32\u62fc\u63a5\u65f6\uff0c\u80fd\u663e\u8457\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n\n\n\n

1. StringBuffer<\/code> \u548c StringBuilder<\/code> \u7684\u533a\u522b<\/strong><\/h3>\n\n\n\n
    \n
  • \u7ebf\u7a0b\u5b89\u5168\u6027<\/strong>\uff1a<\/li>\n\n\n\n
  • StringBuffer<\/code> \u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u5b83\u7684\u6240\u6709\u65b9\u6cd5\u90fd\u88ab synchronized<\/code> \u4fee\u9970\u3002\u8fd9\u610f\u5473\u7740\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\uff0c\u591a\u4e2a\u7ebf\u7a0b\u53ef\u4ee5\u5b89\u5168\u5730\u64cd\u4f5c\u540c\u4e00\u4e2a StringBuffer<\/code> \u5bf9\u8c61\u3002<\/li>\n\n\n\n
  • StringBuilder<\/code> \u662f\u4e0d\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u5b83\u7684\u65b9\u6cd5\u6ca1\u6709\u540c\u6b65\uff0c\u56e0\u6b64\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e0b\u6027\u80fd\u4f18\u4e8e StringBuffer<\/code>\u3002<\/li>\n\n\n\n
  • \u6027\u80fd<\/strong>\uff1a<\/li>\n\n\n\n
  • \u56e0\u4e3a StringBuffer<\/code> \u9700\u8981\u540c\u6b65\uff08\u4fdd\u8bc1\u7ebf\u7a0b\u5b89\u5168\uff09\uff0c\u6240\u4ee5\u5b83\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u7684\u6027\u80fd\u76f8\u5bf9\u8f83\u4f4e\u3002<\/li>\n\n\n\n
  • StringBuilder<\/code> \u6ca1\u6709\u540c\u6b65\u5f00\u9500\uff0c\u56e0\u6b64\u5728\u5355\u7ebf\u7a0b\u73af\u5883\u4e0b\u6bd4 StringBuffer<\/code> \u6027\u80fd\u66f4\u597d\u3002<\/li>\n<\/ul>\n\n\n\n

    \u603b\u7684\u6765\u8bf4\uff0c\u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u4f60\u4e0d\u9700\u8981\u7ebf\u7a0b\u5b89\u5168\uff0c\u63a8\u8350\u4f7f\u7528 StringBuilder<\/code>\uff0c\u56e0\u4e3a\u5b83\u6027\u80fd\u66f4\u9ad8\u3002\u5982\u679c\u9700\u8981\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u4f7f\u7528\uff0c\u9009\u62e9 StringBuffer<\/code>\u3002<\/p>\n\n\n\n

    2. \u5e38\u7528\u65b9\u6cd5<\/strong><\/h3>\n\n\n\n

    StringBuffer<\/code> \u548c StringBuilder<\/code> \u63d0\u4f9b\u4e86\u8bb8\u591a\u76f8\u4f3c\u7684\u65b9\u6cd5\uff0c\u4ee5\u4e0b\u662f\u5e38\u7528\u65b9\u6cd5\u7684\u4ecb\u7ecd\u3002<\/p>\n\n\n\n

    2.1 \u521b\u5efa\u5bf9\u8c61<\/h4>\n\n\n\n
    StringBuffer sb1 = new StringBuffer();  \/\/ \u521b\u5efa\u4e00\u4e2a\u7a7a\u7684 StringBuffer\nStringBuffer sb2 = new StringBuffer(\"Hello\");  \/\/ \u4f7f\u7528\u521d\u59cb\u503c\u521b\u5efa StringBuffer\nStringBuilder sb3 = new StringBuilder(\"Hello\");  \/\/ \u4f7f\u7528\u521d\u59cb\u503c\u521b\u5efa StringBuilder<\/code><\/pre>\n\n\n\n
    2.2 \u83b7\u53d6\u5f53\u524d\u957f\u5ea6\u548c\u5bb9\u91cf<\/h4>\n\n\n\n
      \n
    • length()<\/code>\uff1a\u8fd4\u56de\u5f53\u524d\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002<\/li>\n\n\n\n
    • capacity()<\/code>\uff1a\u8fd4\u56de\u5f53\u524d StringBuffer<\/code> \u6216 StringBuilder<\/code> \u7684\u5bb9\u91cf\uff08\u5373\u5f53\u524d\u5206\u914d\u7684\u5185\u5b58\u5927\u5c0f\uff09\u3002<\/li>\n<\/ul>\n\n\n\n
      StringBuffer sb = new StringBuffer(\"Hello\");\nSystem.out.println(sb.length());  \/\/ \u8f93\u51fa 5\nSystem.out.println(sb.capacity());  \/\/ \u8f93\u51fa 21\uff08\u9ed8\u8ba4\u521d\u59cb\u5bb9\u91cf\u662f 16\uff0c\u52a0\u4e0a 5 \u4e2a\u5b57\u7b26\uff09<\/code><\/pre>\n\n\n\n
      2.3 \u6dfb\u52a0\u5b57\u7b26\u6216\u5b57\u7b26\u4e32<\/h4>\n\n\n\n
        \n
      • append()<\/code>\uff1a\u5411 StringBuffer<\/code> \u6216 StringBuilder<\/code> \u8ffd\u52a0\u5185\u5bb9\u3002<\/li>\n<\/ul>\n\n\n\n
        StringBuffer sb = new StringBuffer(\"Hello\");\nsb.append(\" World\");\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"Hello World\"<\/code><\/pre>\n\n\n\n
        2.4 \u63d2\u5165\u5185\u5bb9<\/h4>\n\n\n\n
          \n
        • insert()<\/code>\uff1a\u5728\u6307\u5b9a\u4f4d\u7f6e\u63d2\u5165\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n\n\n\n
          StringBuffer sb = new StringBuffer(\"Hello World\");\nsb.insert(6, \"Java \");\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"Hello Java World\"<\/code><\/pre>\n\n\n\n
          2.5 \u5220\u9664\u5b57\u7b26<\/h4>\n\n\n\n
            \n
          • delete()<\/code>\uff1a\u5220\u9664\u6307\u5b9a\u8303\u56f4\u7684\u5b57\u7b26\u3002<\/li>\n\n\n\n
          • deleteCharAt()<\/code>\uff1a\u5220\u9664\u6307\u5b9a\u4f4d\u7f6e\u7684\u5b57\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n
            StringBuffer sb = new StringBuffer(\"Hello World\");\nsb.delete(5, 11);  \/\/ \u5220\u9664\u4ece\u7d22\u5f15 5 \u5230 11 \u7684\u90e8\u5206\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"Hello\"\n\nsb.deleteCharAt(4);  \/\/ \u5220\u9664\u7d22\u5f15\u4e3a 4 \u7684\u5b57\u7b26\uff08\u7a7a\u683c\uff09\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"Hell\"<\/code><\/pre>\n\n\n\n
            2.6 \u66ff\u6362\u5b57\u7b26<\/h4>\n\n\n\n
              \n
            • replace()<\/code>\uff1a\u66ff\u6362\u6307\u5b9a\u8303\u56f4\u5185\u7684\u5b57\u7b26\u3002<\/li>\n<\/ul>\n\n\n\n
              StringBuffer sb = new StringBuffer(\"Hello World\");\nsb.replace(6, 11, \"Java\");\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"Hello Java\"<\/code><\/pre>\n\n\n\n
              2.7 \u53cd\u8f6c\u5b57\u7b26\u4e32<\/h4>\n\n\n\n
                \n
              • reverse()<\/code>\uff1a\u53cd\u8f6c\u6574\u4e2a\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n\n\n\n
                StringBuffer sb = new StringBuffer(\"Hello\");\nsb.reverse();\nSystem.out.println(sb);  \/\/ \u8f93\u51fa \"olleH\"<\/code><\/pre>\n\n\n\n
                2.8 \u8f6c\u6362\u4e3a String<\/code><\/h4>\n\n\n\n
                  \n
                • toString()<\/code>\uff1a\u5c06 StringBuffer<\/code> \u6216 StringBuilder<\/code> \u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n\n\n\n
                  StringBuffer sb = new StringBuffer(\"Hello\");\nString str = sb.toString();\nSystem.out.println(str);  \/\/ \u8f93\u51fa \"Hello\"<\/code><\/pre>\n\n\n\n
                  2.9 \u5bb9\u91cf\u7684\u6269\u5c55<\/h4>\n\n\n\n
                    \n
                  • \u5982\u679c StringBuffer<\/code> \u6216 StringBuilder<\/code> \u7684\u5bb9\u91cf\u5df2\u6ee1\uff08\u5373\u5b57\u7b26\u4e32\u957f\u5ea6\u8d85\u8fc7\u5f53\u524d\u5bb9\u91cf\uff09\uff0c\u5b83\u4eec\u4f1a\u81ea\u52a8\u6269\u5bb9\uff0c\u6269\u5bb9\u540e\u7684\u65b0\u5bb9\u91cf\u4e3a\u539f\u5bb9\u91cf\u7684 2 \u500d\u52a0 2\u3002<\/li>\n<\/ul>\n\n\n\n
                    StringBuffer sb = new StringBuffer();\nSystem.out.println(sb.capacity());  \/\/ \u9ed8\u8ba4\u5bb9\u91cf 16\nsb.append(\"Hello\");\nSystem.out.println(sb.capacity());  \/\/ \u5982\u679c\u957f\u5ea6\u5927\u4e8e 16\uff0c\u5bb9\u91cf\u5c06\u81ea\u52a8\u589e\u52a0<\/code><\/pre>\n\n\n\n
                    3. \u793a\u4f8b\u4ee3\u7801<\/strong><\/h3>\n\n\n\n
                    3.1 StringBuffer<\/code> \u793a\u4f8b<\/h4>\n\n\n\n
                    public class StringBufferExample {\n    public static void main(String[] args) {\n        \/\/ \u521b\u5efa StringBuffer \u5bf9\u8c61\n        StringBuffer sb = new StringBuffer(\"Java\");\n\n        \/\/ \u4f7f\u7528 append() \u65b9\u6cd5\u62fc\u63a5\u5b57\u7b26\u4e32\n        sb.append(\" Programming\");\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Java Programming\"\n\n        \/\/ \u4f7f\u7528 insert() \u5728\u6307\u5b9a\u4f4d\u7f6e\u63d2\u5165\u5185\u5bb9\n        sb.insert(4, \" Language\");\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Java Language Programming\"\n\n        \/\/ \u4f7f\u7528 replace() \u66ff\u6362\u5b57\u7b26\u4e32\n        sb.replace(0, 4, \"Python\");\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Python Language Programming\"\n\n        \/\/ \u4f7f\u7528 delete() \u5220\u9664\u90e8\u5206\u5b57\u7b26\n        sb.delete(7, 15);\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Python Programming\"\n\n        \/\/ \u4f7f\u7528 reverse() \u53cd\u8f6c\u5b57\u7b26\u4e32\n        sb.reverse();\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"gnimmargorP nohtyP\"\n    }\n}<\/code><\/pre>\n\n\n\n
                    \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
                    Java Programming\nJava Language Programming\nPython Language Programming\nPython Programming\ngnimmargorP nohtyP<\/code><\/pre>\n\n\n\n
                    3.2 StringBuilder<\/code> \u793a\u4f8b<\/h4>\n\n\n\n
                    public class StringBuilderExample {\n    public static void main(String[] args) {\n        \/\/ \u521b\u5efa StringBuilder \u5bf9\u8c61\n        StringBuilder sb = new StringBuilder(\"Hello\");\n\n        \/\/ \u4f7f\u7528 append() \u62fc\u63a5\u5b57\u7b26\u4e32\n        sb.append(\" World\");\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Hello World\"\n\n        \/\/ \u4f7f\u7528 insert() \u63d2\u5165\u5185\u5bb9\n        sb.insert(6, \" Java\");\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Hello Java World\"\n\n        \/\/ \u4f7f\u7528 deleteCharAt() \u5220\u9664\u5b57\u7b26\n        sb.deleteCharAt(10);\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"Hello Java World\"\n\n        \/\/ \u4f7f\u7528 reverse() \u53cd\u8f6c\u5b57\u7b26\u4e32\n        sb.reverse();\n        System.out.println(sb);  \/\/ \u8f93\u51fa \"dlroW avaJ olleH\"\n    }\n}<\/code><\/pre>\n\n\n\n
                    \u8f93\u51fa\uff1a<\/strong><\/p>\n\n\n\n
                    Hello World\nHello Java World\nHello Java Wrld\ndlroW avaJ olleH<\/code><\/pre>\n\n\n\n
                    4. \u603b\u7ed3<\/strong><\/h3>\n\n\n\n
                      \n
                    • StringBuffer<\/code> \u548c StringBuilder<\/code><\/strong> \u90fd\u63d0\u4f9b\u4e86\u53ef\u53d8\u5b57\u7b26\u4e32\u7684\u529f\u80fd\uff0c\u9002\u7528\u4e8e\u9891\u7e41\u4fee\u6539\u5b57\u7b26\u4e32\u7684\u573a\u666f\u3002<\/li>\n\n\n\n
                    • StringBuffer<\/code><\/strong> \u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u9002\u7528\u4e8e\u591a\u7ebf\u7a0b\u73af\u5883\uff0c\u4f46\u6027\u80fd\u8f83\u5dee\u3002<\/li>\n\n\n\n
                    • StringBuilder<\/code><\/strong> \u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u9002\u7528\u4e8e\u5355\u7ebf\u7a0b\u73af\u5883\uff0c\u6027\u80fd\u66f4\u4f18\u3002<\/li>\n\n\n\n
                    • \u5b83\u4eec\u7684\u5e38\u7528\u64cd\u4f5c\u5305\u62ec\uff1aappend()<\/code>\u3001insert()<\/code>\u3001delete()<\/code>\u3001replace()<\/code>\u3001reverse()<\/code> \u7b49\u3002<\/li>\n<\/ul>\n\n\n\n
                      \u5728\u9009\u62e9\u4f7f\u7528\u54ea\u4e2a\u7c7b\u65f6\uff0c\u901a\u5e38\u5efa\u8bae\u5728\u4e0d\u9700\u8981\u7ebf\u7a0b\u5b89\u5168\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528 StringBuilder<\/code>\uff0c\u4ee5\u83b7\u5f97\u66f4\u597d\u7684\u6027\u80fd\u3002\u5982\u679c\u4f60\u786e\u5b9e\u9700\u8981\u7ebf\u7a0b\u5b89\u5168\uff0c\u5219\u53ef\u4ee5\u4f7f\u7528 StringBuffer<\/code>\u3002<\/p>\n\n\n\n
                      \u5e0c\u671b\u8fd9\u4e9b\u5185\u5bb9\u80fd\u591f\u5e2e\u52a9\u4f60\u7406\u89e3 StringBuffer<\/code> \u548c StringBuilder<\/code> \u7684\u4f7f\u7528\uff01\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\uff0c\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
                      StringBuffer \u548c StringBuilder \u7c7b\u662f Java \u4e2d\u7528\u4e8e\u5904\u7406\u53ef\u53d8\u5b57\u7b26\u4e32\u7684\u7c7b\uff0c\u5b83\u4eec\u63d0\u4f9b\u4e86 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68],"tags":[],"class_list":["post-2208","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2208","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=2208"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2208\/revisions"}],"predecessor-version":[{"id":2209,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/2208\/revisions\/2209"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=2208"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=2208"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=2208"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}