{"id":270,"date":"2026-02-02T17:01:50","date_gmt":"2026-02-02T09:01:50","guid":{"rendered":"http:\/\/47.100.165.17\/wordpress\/?p=270"},"modified":"2026-03-04T21:58:39","modified_gmt":"2026-03-04T13:58:39","slug":"%e3%80%90java%e3%80%91%e4%b8%80%e6%96%87%e6%90%9e%e6%87%82string%e6%ba%90%e7%a0%81","status":"publish","type":"post","link":"https:\/\/yunyanglib.cn\/?p=270","title":{"rendered":"\u3010Java\u3011\u4e00\u6587\u641e\u61c2String\u6e90\u7801"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5728 Java \u5f00\u53d1\u4e2d\uff0cString \u7c7b\u662f\u6211\u4eec\u65e5\u5e38\u4f7f\u7528\u9891\u7387\u6781\u9ad8\u7684\u7c7b\u4e4b\u4e00\uff0c\u4ece\u7b80\u5355\u7684\u5b57\u7b26\u4e32\u62fc\u63a5\u5230\u590d\u6742\u7684\u6587\u672c\u5904\u7406\uff0c\u90fd\u79bb\u4e0d\u5f00\u5b83\u7684\u8eab\u5f71\u3002\u4f46\u5f88\u591a\u65f6\u5019\uff0c\u6211\u4eec\u53ea\u662f\u505c\u7559\u5728 \u201c\u4f1a\u7528\u201d \u7684\u5c42\u9762\uff0c\u5bf9\u5176\u5e95\u5c42\u6e90\u7801\u7684\u8bbe\u8ba1\u903b\u8f91\u548c\u7279\u6027\u4e86\u89e3\u751a\u5c11\u3002\u4eca\u5929\uff0c\u5c31\u8ba9\u6211\u4eec\u4e00\u8d77\u6df1\u5165 String \u6e90\u7801\uff0c\u63ed\u5f00\u5b83\u7684\u795e\u79d8\u9762\u7eb1\uff0c\u641e\u61c2\u90a3\u4e9b\u85cf\u5728\u4ee3\u7801\u80cc\u540e\u7684\u8bbe\u8ba1\u601d\u60f3\u4e0e\u5173\u952e\u7ec6\u8282\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><a><\/a>\u4e00\u3001String \u7c7b\u7684\u6838\u5fc3\u7279\u6027\uff1a\u4e0d\u53ef\u53d8\u6027<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u6253\u5f00 JDK \u6e90\u7801\uff0c\u6211\u4eec\u4f1a\u53d1\u73b0 String \u7c7b\u88ab<code>final<\/code>\u5173\u952e\u5b57\u4fee\u9970\uff0c\u8fd9\u610f\u5473\u7740 String \u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\u3002\u540c\u65f6\uff0c\u5176\u5185\u90e8\u5b58\u50a8\u5b57\u7b26\u4e32\u7684\u6210\u5458\u53d8\u91cf<code>value<\/code>\uff08\u5728 JDK 1.8 \u53ca\u4e4b\u524d\u4e3a<code>char[]<\/code>\u7c7b\u578b\uff0cJDK 1.9 \u4e4b\u540e\u6539\u4e3a<code>byte[]<\/code>\u7c7b\u578b\uff09\u4e5f\u88ab<code>private final<\/code>\u4fee\u9970\u3002\u8fd9\u4e24\u4e2a\u5173\u952e\u8bbe\u8ba1\uff0c\u5171\u540c\u51b3\u5b9a\u4e86 String \u7c7b\u7684\u6838\u5fc3\u7279\u6027 \u2014\u2014<strong>\u4e0d\u53ef\u53d8\u6027<\/strong>\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><em>\/\/ JDK 1.8 String\u7c7b\u6838\u5fc3\u6210\u5458\u53d8\u91cf<\/em>\nprivate final char value&#91;];\n\n<em>\/\/ JDK 1.9 String\u7c7b\u6838\u5fc3\u6210\u5458\u53d8\u91cf<\/em>\nprivate final byte&#91;] value;\nprivate final byte coder; <em>\/\/ \u7528\u4e8e\u6807\u8bc6\u7f16\u7801\u683c\u5f0f\uff0c0\u8868\u793aLatin-1\uff0c1\u8868\u793aUTF-16<\/em>\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e0d\u53ef\u53d8\u6027\u610f\u5473\u7740\u4e00\u65e6 String \u5bf9\u8c61\u88ab\u521b\u5efa\uff0c\u5176\u5185\u90e8\u7684\u5b57\u7b26\u5e8f\u5217\u5c31\u65e0\u6cd5\u88ab\u4fee\u6539\u3002\u6bd4\u5982\u6211\u4eec\u6267\u884c<code>String str = \"abc\"; str += \"d\";<\/code>\u65f6\uff0c\u770b\u4f3c\u662f\u4fee\u6539\u4e86 str \u7684\u503c\uff0c\u5b9e\u5219\u662f\u521b\u5efa\u4e86\u4e00\u4e2a\u65b0\u7684 String \u5bf9\u8c61<code>\"abcd\"<\/code>\uff0c\u5e76\u5c06 str \u7684\u5f15\u7528\u6307\u5411\u4e86\u8fd9\u4e2a\u65b0\u5bf9\u8c61\uff0c\u539f\u5bf9\u8c61<code>\"abc\"<\/code>\u4f9d\u7136\u5b58\u5728\u4e8e\u5185\u5b58\u4e2d\uff08\u540e\u7eed\u4f1a\u88ab\u5783\u573e\u56de\u6536\u673a\u5236\u5904\u7406\uff09\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u79cd\u8bbe\u8ba1\u5e26\u6765\u4e86\u8bf8\u591a\u597d\u5904\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u7ebf\u7a0b\u5b89\u5168<\/strong>\uff1a\u7531\u4e8e\u5bf9\u8c61\u4e0d\u53ef\u4fee\u6539\uff0c\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u65e0\u9700\u62c5\u5fc3\u7ebf\u7a0b\u5b89\u5168\u95ee\u9898\uff0c\u65e0\u9700\u989d\u5916\u52a0\u9501\u3002<\/li>\n\n\n\n<li><strong>\u53ef\u7f13\u5b58\u54c8\u5e0c\u503c<\/strong>\uff1aString \u7c7b\u7684<code>hashCode()<\/code>\u65b9\u6cd5\u4f1a\u6839\u636e<code>value<\/code>\u8ba1\u7b97\u54c8\u5e0c\u503c\uff0c\u7531\u4e8e<code>value<\/code>\u4e0d\u53ef\u53d8\uff0c\u54c8\u5e0c\u503c\u53ea\u9700\u8ba1\u7b97\u4e00\u6b21\u5e76\u7f13\u5b58\u8d77\u6765\uff0c\u540e\u7eed\u8c03\u7528<code>hashCode()<\/code>\u53ef\u76f4\u63a5\u8fd4\u56de\uff0c\u63d0\u5347\u6548\u7387\uff08\u8fd9\u4e5f\u662f HashMap \u7b49\u96c6\u5408\u4e2d\u5e38\u7528 String \u4f5c\u4e3a\u952e\u7684\u91cd\u8981\u539f\u56e0\uff09\u3002<\/li>\n\n\n\n<li><strong>\u5e38\u91cf\u6c60\u590d\u7528<\/strong>\uff1aJava \u4e2d\u7684\u5b57\u7b26\u4e32\u5e38\u91cf\u6c60\uff08String Pool\uff09\u53ef\u4ee5\u590d\u7528\u76f8\u540c\u5185\u5bb9\u7684 String \u5bf9\u8c61\uff0c\u51cf\u5c11\u5185\u5b58\u5360\u7528\u3002\u6bd4\u5982<code>String a = \"abc\"; String b = \"abc\";<\/code>\uff0ca \u548c b \u4f1a\u6307\u5411\u5e38\u91cf\u6c60\u4e2d\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><a><\/a>\u4e8c\u3001\u5e95\u5c42\u5b58\u50a8\u7684\u6f14\u53d8\uff1a\u4ece char [] \u5230 byte []<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 JDK 1.8 \u53ca\u4e4b\u524d\uff0cString \u7c7b\u4f7f\u7528<code>char[]<\/code>\u5b58\u50a8\u5b57\u7b26\uff0c\u6bcf\u4e2a<code>char<\/code>\u5360 2 \u4e2a\u5b57\u8282\uff08UTF-16 \u7f16\u7801\uff09\u3002\u4f46\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0c\u5927\u90e8\u5206\u5b57\u7b26\u4e32\u662f\u7531 Latin-1 \u5b57\u7b26\uff08\u5982\u82f1\u6587\u5b57\u6bcd\u3001\u6570\u5b57\u3001\u5e38\u89c1\u7b26\u53f7\uff09\u7ec4\u6210\uff0c\u8fd9\u7c7b\u5b57\u7b26\u53ea\u9700 1 \u4e2a\u5b57\u8282\u5c31\u80fd\u5b58\u50a8\u3002\u4f7f\u7528<code>char[]<\/code>\u5b58\u50a8\u4f1a\u9020\u6210\u5927\u91cf\u5185\u5b58\u6d6a\u8d39\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0cJDK 1.9 \u5bf9 String \u7684\u5e95\u5c42\u5b58\u50a8\u8fdb\u884c\u4e86\u4f18\u5316\uff0c\u5c06<code>char[]<\/code>\u6539\u4e3a<code>byte[]<\/code>\uff0c\u5e76\u65b0\u589e\u4e86<code>coder<\/code>\u6210\u5458\u53d8\u91cf\u6765\u6807\u8bc6\u7f16\u7801\u683c\u5f0f\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5f53<code>coder = 0<\/code>\u65f6\uff0c\u4f7f\u7528 Latin-1 \u7f16\u7801\uff0c\u6bcf\u4e2a\u5b57\u7b26\u5360 1 \u4e2a\u5b57\u8282\uff0c\u9002\u7528\u4e8e\u5b58\u50a8\u82f1\u6587\u5b57\u7b26\u7b49\u3002<\/li>\n\n\n\n<li>\u5f53<code>coder = 1<\/code>\u65f6\uff0c\u4f7f\u7528 UTF-16 \u7f16\u7801\uff0c\u6bcf\u4e2a\u5b57\u7b26\u5360 2 \u4e2a\u5b57\u8282\uff0c\u9002\u7528\u4e8e\u5b58\u50a8\u4e2d\u6587\u3001\u7279\u6b8a\u7b26\u53f7\u7b49\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u8fd9\u79cd\u81ea\u9002\u5e94\u7f16\u7801\u7684\u8bbe\u8ba1\uff0c\u5728\u4fdd\u8bc1\u529f\u80fd\u4e0d\u53d7\u5f71\u54cd\u7684\u524d\u63d0\u4e0b\uff0c\u5927\u5e45\u51cf\u5c11\u4e86\u5185\u5b58\u5360\u7528\uff0c\u5c24\u5176\u5728\u5904\u7406\u5927\u91cf\u82f1\u6587\u5b57\u7b26\u4e32\u7684\u573a\u666f\u4e0b\uff0c\u4f18\u5316\u6548\u679c\u663e\u8457\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><a><\/a>\u4e09\u3001\u5e38\u7528\u65b9\u6cd5\u7684\u6e90\u7801\u89e3\u6790<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>1. equals () \u65b9\u6cd5\uff1a\u5224\u65ad\u5b57\u7b26\u4e32\u5185\u5bb9\u662f\u5426\u76f8\u7b49<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">String \u7c7b\u91cd\u5199\u4e86 Object \u7c7b\u7684<code>equals()<\/code>\u65b9\u6cd5\uff0c\u5176\u6838\u5fc3\u903b\u8f91\u662f\u9010\u5b57\u7b26\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u662f\u5426\u4e00\u81f4\uff0c\u5177\u4f53\u6b65\u9aa4\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u5148\u5224\u65ad\u4e24\u4e2a\u5bf9\u8c61\u7684\u5f15\u7528\u662f\u5426\u76f8\u540c\uff0c\u82e5\u76f8\u540c\u76f4\u63a5\u8fd4\u56de<code>true<\/code>\u3002<\/li>\n\n\n\n<li>\u5224\u65ad\u4f20\u5165\u7684\u5bf9\u8c61\u662f\u5426\u4e3a String \u7c7b\u578b\uff0c\u82e5\u4e0d\u662f\u76f4\u63a5\u8fd4\u56de<code>false<\/code>\u3002<\/li>\n\n\n\n<li>\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u548c\u7f16\u7801\u683c\u5f0f\uff08JDK 1.9 \u53ca\u4e4b\u540e\uff09\uff0c\u82e5\u4e0d\u4e00\u81f4\u8fd4\u56de<code>false<\/code>\u3002<\/li>\n\n\n\n<li>\u9010\u5b57\u7b26\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684<code>value<\/code>\u6570\u7ec4\uff0c\u82e5\u6240\u6709\u5b57\u7b26\u90fd\u76f8\u540c\u5219\u8fd4\u56de<code>true<\/code>\uff0c\u5426\u5219\u8fd4\u56de<code>false<\/code>\u3002<\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code><em>\/\/ JDK 1.9 String\u7c7bequals()\u65b9\u6cd5\u6838\u5fc3\u4ee3\u7801<\/em>\npublic boolean equals(Object anObject) {\n    if (this == anObject) {\n        return true;\n    }\n    if (anObject instanceof String) {\n        String aString = (String)anObject;\n        if (coder() == aString.coder()) {\n            return isLatin1() ? StringLatin1.equals(value, aString.value)\n                              : StringUTF16.equals(value, aString.value);\n        }\n    }\n    return false;\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>2. hashCode () \u65b9\u6cd5\uff1a\u8ba1\u7b97\u5b57\u7b26\u4e32\u7684\u54c8\u5e0c\u503c<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">String \u7c7b\u7684<code>hashCode()<\/code>\u65b9\u6cd5\u6839\u636e<code>value<\/code>\u6570\u7ec4\u7684\u5185\u5bb9\u8ba1\u7b97\u54c8\u5e0c\u503c\uff0c\u8ba1\u7b97\u516c\u5f0f\u4e3a\uff1a<code>hash = 31 * hash + val[i]<\/code>\uff08\u5176\u4e2d<code>val[i]<\/code>\u662f\u5b57\u7b26\u4e32\u7b2c i \u4e2a\u5b57\u7b26\u7684 ASCII \u503c\uff09\u3002\u9009\u62e9 31 \u4f5c\u4e3a\u4e58\u6570\uff0c\u662f\u56e0\u4e3a 31 \u662f\u4e00\u4e2a\u8d28\u6570\uff0c\u4e14<code>31 * x<\/code>\u53ef\u4ee5\u88ab\u4f18\u5316\u4e3a<code>(x &lt;&lt; 5) - x<\/code>\uff08\u79fb\u4f4d\u8fd0\u7b97\u6bd4\u4e58\u6cd5\u8fd0\u7b97\u6548\u7387\u66f4\u9ad8\uff09\uff0c\u540c\u65f6 31 \u80fd\u6709\u6548\u51cf\u5c11\u54c8\u5e0c\u51b2\u7a81\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><em>\/\/ JDK 1.8 String\u7c7bhashCode()\u65b9\u6cd5<\/em>\nprivate int hash; <em>\/\/ \u7f13\u5b58\u5b57\u7b26\u4e32\u7684\u54c8\u5e0c\u7801<\/em>\n\npublic int hashCode() {\n    int h = hash; <em>\/\/ \u4ece\u7f13\u5b58\u4e2d\u83b7\u53d6\u54c8\u5e0c\u7801<\/em>\n    <em>\/\/ \u5982\u679c\u54c8\u5e0c\u7801\u672a\u88ab\u8ba1\u7b97\u8fc7\uff08\u5373\u4e3a 0\uff09\u4e14\u5b57\u7b26\u4e32\u4e0d\u4e3a\u7a7a\uff0c\u5219\u8ba1\u7b97\u54c8\u5e0c\u7801<\/em>\n    if (h == 0 &amp;&amp; value.length &gt; 0) {\n        char val&#91;] = value; <em>\/\/ \u83b7\u53d6\u5b57\u7b26\u4e32\u7684\u5b57\u7b26\u6570\u7ec4<\/em>\n\n        <em>\/\/ \u904d\u5386\u5b57\u7b26\u4e32\u7684\u6bcf\u4e2a\u5b57\u7b26\u6765\u8ba1\u7b97\u54c8\u5e0c\u7801<\/em>\n        for (int i = 0; i &lt; value.length; i++) {\n            h = 31 * h + val&#91;i]; <em>\/\/ \u4f7f\u7528 31 \u4f5c\u4e3a\u4e58\u6cd5\u56e0\u5b50<\/em>\n        }\n        hash = h; <em>\/\/ \u7f13\u5b58\u8ba1\u7b97\u540e\u7684\u54c8\u5e0c\u7801<\/em>\n    }\n    return h; <em>\/\/ \u8fd4\u56de\u54c8\u5e0c\u7801<\/em>\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>3. substring () \u65b9\u6cd5\uff1a\u622a\u53d6\u5b57\u7b26\u4e32\uff08JDK 1.7 \u524d\u540e\u5dee\u5f02\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5728 JDK 1.7 \u4e4b\u524d\uff0c<code>substring()<\/code>\u65b9\u6cd5\u901a\u8fc7\u521b\u5efa\u65b0\u7684 String \u5bf9\u8c61\uff0c\u5e76\u5171\u4eab\u539f\u5bf9\u8c61\u7684<code>value<\/code>\u6570\u7ec4\uff0c\u53ea\u4fee\u6539\u65b0\u5bf9\u8c61\u7684<code>offset<\/code>\uff08\u504f\u79fb\u91cf\uff09\u548c<code>count<\/code>\uff08\u957f\u5ea6\uff09\u6765\u5b9e\u73b0\u622a\u53d6\u3002\u8fd9\u79cd\u8bbe\u8ba1\u867d\u7136\u9ad8\u6548\uff0c\u4f46\u4f1a\u5bfc\u81f4\u539f\u5bf9\u8c61\u7684<code>value<\/code>\u6570\u7ec4\u65e0\u6cd5\u88ab\u5783\u573e\u56de\u6536\uff08\u5373\u4f7f\u539f\u5bf9\u8c61\u4e0d\u518d\u4f7f\u7528\uff0c\u53ea\u8981\u622a\u53d6\u540e\u7684\u5bf9\u8c61\u5b58\u5728\uff0c<code>value<\/code>\u6570\u7ec4\u5c31\u4f1a\u88ab\u5f15\u7528\uff09\uff0c\u5bb9\u6613\u9020\u6210\u5185\u5b58\u6cc4\u6f0f\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">JDK 1.7 \u53ca\u4e4b\u540e\uff0c<code>substring()<\/code>\u65b9\u6cd5\u8fdb\u884c\u4e86\u4f18\u5316\uff0c\u4e0d\u518d\u5171\u4eab\u539f\u5bf9\u8c61\u7684<code>value<\/code>\u6570\u7ec4\uff0c\u800c\u662f\u901a\u8fc7\u590d\u5236\u539f\u6570\u7ec4\u7684\u6307\u5b9a\u90e8\u5206\u6765\u521b\u5efa\u65b0\u7684<code>value<\/code>\u6570\u7ec4\uff0c\u4ece\u6839\u672c\u4e0a\u89e3\u51b3\u4e86\u5185\u5b58\u6cc4\u6f0f\u95ee\u9898\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><em>\/\/ JDK 1.8 String\u7c7bsubstring()\u65b9\u6cd5<\/em>\npublic String substring(int beginIndex) {\n    <em>\/\/ \u68c0\u67e5\u8d77\u59cb\u7d22\u5f15\u662f\u5426\u5c0f\u4e8e 0\uff0c\u5982\u679c\u662f\uff0c\u5219\u629b\u51fa StringIndexOutOfBoundsException \u5f02\u5e38<\/em>\n    if (beginIndex &lt; 0) {\n        throw new StringIndexOutOfBoundsException(beginIndex);\n    }\n    <em>\/\/ \u8ba1\u7b97\u5b50\u5b57\u7b26\u4e32\u7684\u957f\u5ea6<\/em>\n    int subLen = value.length - beginIndex;\n    <em>\/\/ \u68c0\u67e5\u5b50\u5b57\u7b26\u4e32\u957f\u5ea6\u662f\u5426\u4e3a\u8d1f\u6570\uff0c\u5982\u679c\u662f\uff0c\u5219\u629b\u51fa StringIndexOutOfBoundsException \u5f02\u5e38<\/em>\n    if (subLen &lt; 0) {\n        throw new StringIndexOutOfBoundsException(subLen);\n    }\n    <em>\/\/ \u5982\u679c\u8d77\u59cb\u7d22\u5f15\u4e3a 0\uff0c\u5219\u8fd4\u56de\u539f\u5b57\u7b26\u4e32\uff1b\u5426\u5219\uff0c\u521b\u5efa\u5e76\u8fd4\u56de\u65b0\u7684\u5b57\u7b26\u4e32<\/em>\n    return (beginIndex == 0) ? this : new String(value, beginIndex, subLen);\n}\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><a><\/a>4. indexOf()\u65b9\u6cd5\uff1a\u67e5\u627e\u5b50\u4e32\u5728\u539f\u5b57\u7b26\u4e32\u5185\u7684\u7d22\u5f15<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">indexOf \u65b9\u6cd5\u7528\u4e8e\u67e5\u627e\u4e00\u4e2a\u5b50\u5b57\u7b26\u4e32\u5728\u539f\u5b57\u7b26\u4e32\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\uff0c\u5e76\u8fd4\u56de\u8be5\u4f4d\u7f6e\u7684\u7d22\u5f15\u3002\u6765\u770b\u8be5\u65b9\u6cd5\u7684\u6e90\u7801\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><em>\/*\n * \u67e5\u627e\u5b57\u7b26\u6570\u7ec4 target \u5728\u5b57\u7b26\u6570\u7ec4 source \u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u4f4d\u7f6e\u3002\n * sourceOffset \u548c sourceCount \u53c2\u6570\u6307\u5b9a source \u6570\u7ec4\u4e2d\u8981\u641c\u7d22\u7684\u8303\u56f4\uff0c\n * targetOffset \u548c targetCount \u53c2\u6570\u6307\u5b9a target \u6570\u7ec4\u4e2d\u8981\u641c\u7d22\u7684\u8303\u56f4\uff0c\n * fromIndex \u53c2\u6570\u6307\u5b9a\u5f00\u59cb\u641c\u7d22\u7684\u4f4d\u7f6e\u3002\n * \u5982\u679c\u627e\u5230\u4e86 target \u6570\u7ec4\uff0c\u5219\u8fd4\u56de\u5b83\u5728 source \u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\u7d22\u5f15\uff08\u4ece0\u5f00\u59cb\uff09\uff0c\n * \u5426\u5219\u8fd4\u56de-1\u3002\n *\/<\/em>\nstatic int indexOf(char&#91;] source, int sourceOffset, int sourceCount,\n        char&#91;] target, int targetOffset, int targetCount,\n        int fromIndex) {\n    <em>\/\/ \u5982\u679c\u5f00\u59cb\u641c\u7d22\u7684\u4f4d\u7f6e\u5df2\u7ecf\u8d85\u51fa source \u6570\u7ec4\u7684\u8303\u56f4\uff0c\u5219\u76f4\u63a5\u8fd4\u56de-1\uff08\u5982\u679c target \u6570\u7ec4\u4e3a\u7a7a\uff0c\u5219\u8fd4\u56de sourceCount\uff09<\/em>\n    if (fromIndex &gt;= sourceCount) {\n        return (targetCount == 0 ? sourceCount : -1);\n    }\n    <em>\/\/ \u5982\u679c\u5f00\u59cb\u641c\u7d22\u7684\u4f4d\u7f6e\u5c0f\u4e8e0\uff0c\u5219\u4ece0\u5f00\u59cb\u641c\u7d22<\/em>\n    if (fromIndex &lt; 0) {\n        fromIndex = 0;\n    }\n    <em>\/\/ \u5982\u679c target \u6570\u7ec4\u4e3a\u7a7a\uff0c\u5219\u76f4\u63a5\u8fd4\u56de\u5f00\u59cb\u641c\u7d22\u7684\u4f4d\u7f6e<\/em>\n    if (targetCount == 0) {\n        return fromIndex;\n    }\n\n    <em>\/\/ \u67e5\u627e target \u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\u5728 source \u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e<\/em>\n    char first = target&#91;targetOffset];\n    int max = sourceOffset + (sourceCount - targetCount);\n\n    <em>\/\/ \u5faa\u73af\u67e5\u627e target \u6570\u7ec4\u5728 source \u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e<\/em>\n    for (int i = sourceOffset + fromIndex; i &lt;= max; i++) {\n        <em>\/* Look for first character. *\/<\/em>\n        <em>\/\/ \u5982\u679c source \u6570\u7ec4\u4e2d\u5f53\u524d\u4f4d\u7f6e\u7684\u5b57\u7b26\u4e0d\u662f target \u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\uff0c\u5219\u5728 source \u6570\u7ec4\u4e2d\u7ee7\u7eed\u67e5\u627e target \u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26<\/em>\n        if (source&#91;i] != first) {\n            while (++i &lt;= max &amp;&amp; source&#91;i] != first);\n        }\n\n        <em>\/* Found first character, now look at the rest of v2 *\/<\/em>\n        <em>\/\/ \u5982\u679c\u5728 source \u6570\u7ec4\u4e2d\u627e\u5230\u4e86 target \u6570\u7ec4\u7684\u7b2c\u4e00\u4e2a\u5b57\u7b26\uff0c\u5219\u7ee7\u7eed\u67e5\u627e target \u6570\u7ec4\u7684\u5269\u4f59\u90e8\u5206\u662f\u5426\u5339\u914d<\/em>\n        if (i &lt;= max) {\n            int j = i + 1;\n            int end = j + targetCount - 1;\n            for (int k = targetOffset + 1; j &lt; end &amp;&amp; source&#91;j]\n                    == target&#91;k]; j++, k++);\n\n            <em>\/\/ \u5982\u679c target \u6570\u7ec4\u5168\u90e8\u5339\u914d\uff0c\u5219\u8fd4\u56de\u5728 source \u6570\u7ec4\u4e2d\u7684\u4f4d\u7f6e\u7d22\u5f15<\/em>\n            if (j == end) {\n                <em>\/* Found whole string. *\/<\/em>\n                return i - sourceOffset;\n            }\n        }\n    }\n    <em>\/\/ \u6ca1\u6709\u627e\u5230 target \u6570\u7ec4\uff0c\u5219\u8fd4\u56de-1<\/em>\n    return -1;\n}\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><a><\/a>\u56db\u3001\u5f00\u53d1\u4e2d\u7684\u6ce8\u610f\u4e8b\u9879<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u907f\u514d\u9891\u7e41\u5b57\u7b26\u4e32\u62fc\u63a5<\/strong>\uff1a\u7531\u4e8e String \u7684\u4e0d\u53ef\u53d8\u6027\uff0c\u4f7f\u7528<code>+<\/code>\u8fdb\u884c\u9891\u7e41\u5b57\u7b26\u4e32\u62fc\u63a5\u4f1a\u521b\u5efa\u5927\u91cf\u4e34\u65f6\u5bf9\u8c61\uff0c\u5bfc\u81f4\u5185\u5b58\u6d6a\u8d39\u548c\u6027\u80fd\u4e0b\u964d\u3002\u6b64\u65f6\u5e94\u4f7f\u7528<code>StringBuilder<\/code>\uff08\u975e\u7ebf\u7a0b\u5b89\u5168\uff0c\u6548\u7387\u9ad8\uff09\u6216<code>StringBuffer<\/code>\uff08\u7ebf\u7a0b\u5b89\u5168\uff0c\u6548\u7387\u8f83\u4f4e\uff09\u3002<\/li>\n\n\n\n<li><strong>\u5408\u7406\u4f7f\u7528 intern () \u65b9\u6cd5<\/strong>\uff1a<code>intern()<\/code>\u65b9\u6cd5\u4f1a\u5c06\u5b57\u7b26\u4e32\u5bf9\u8c61\u52a0\u5165\u5e38\u91cf\u6c60\uff08\u82e5\u5e38\u91cf\u6c60\u4e2d\u4e0d\u5b58\u5728\u8be5\u5bf9\u8c61\uff09\uff0c\u5e76\u8fd4\u56de\u5e38\u91cf\u6c60\u4e2d\u7684\u5f15\u7528\u3002\u5408\u7406\u4f7f\u7528<code>intern()<\/code>\u53ef\u4ee5\u51cf\u5c11\u91cd\u590d\u5bf9\u8c61\u7684\u521b\u5efa\uff0c\u4f46\u8fc7\u5ea6\u4f7f\u7528\u4f1a\u589e\u52a0\u5e38\u91cf\u6c60\u7684\u8d1f\u62c5\uff0c\u9700\u6839\u636e\u5b9e\u9645\u573a\u666f\u6743\u8861\u3002<\/li>\n\n\n\n<li><strong>\u533a\u5206\u7a7a\u5b57\u7b26\u4e32\u4e0e null<\/strong>\uff1a<code>\"\"<\/code>\u662f\u4e00\u4e2a\u957f\u5ea6\u4e3a 0 \u7684 String \u5bf9\u8c61\uff0c\u5176<code>value<\/code>\u6570\u7ec4\u957f\u5ea6\u4e3a 0\uff1b\u800c<code>null<\/code>\u8868\u793a\u6ca1\u6709\u5f15\u7528\u4efb\u4f55\u5bf9\u8c61\u3002\u5728\u4f7f\u7528 String \u5bf9\u8c61\u524d\uff0c\u9700\u6ce8\u610f\u5224\u65ad\u662f\u5426\u4e3a<code>null<\/code>\uff0c\u907f\u514d\u7a7a\u6307\u9488\u5f02\u5e38\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u5e0c\u671b\u901a\u8fc7\u672c\u6587\u7684\u8bb2\u89e3\uff0c\u5927\u5bb6\u80fd\u5bf9 String \u6e90\u7801\u6709\u66f4\u6e05\u6670\u7684\u8ba4\u8bc6\u3002\u5982\u679c\u6709\u7591\u95ee\u6216\u8865\u5145\uff0c\u6b22\u8fce\u5728\u8bc4\u8bba\u533a\u4ea4\u6d41\u8ba8\u8bba\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Java \u5f00\u53d1\u4e2d\uff0cString \u7c7b\u662f\u6211\u4eec\u65e5\u5e38\u4f7f\u7528\u9891\u7387\u6781\u9ad8\u7684\u7c7b\u4e4b\u4e00\uff0c\u4ece\u7b80\u5355\u7684\u5b57\u7b26\u4e32\u62fc\u63a5\u5230\u590d\u6742\u7684\u6587\u672c\u5904\u7406\uff0c\u90fd\u79bb<\/p>\n<div class=\"more-link\">\n\t\t\t\t <a href=\"https:\/\/yunyanglib.cn\/?p=270\" class=\"link-btn theme-btn\"><span>Read More <\/span> <i class=\"fa fa-caret-right\"><\/i><\/a>\n\t\t\t<\/div>\n","protected":false},"author":1,"featured_media":272,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[15],"class_list":["post-270","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\/270","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=270"}],"version-history":[{"count":3,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/270\/revisions"}],"predecessor-version":[{"id":934,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/posts\/270\/revisions\/934"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=\/wp\/v2\/media\/272"}],"wp:attachment":[{"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yunyanglib.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}