{"id":266,"date":"2025-09-11T10:35:13","date_gmt":"2025-09-11T02:35:13","guid":{"rendered":"http:\/\/43.139.99.192\/?p=266"},"modified":"2025-09-12T15:33:51","modified_gmt":"2025-09-12T07:33:51","slug":"java%e9%9d%a2%e8%af%95-%e4%bb%a3%e7%a0%81%e8%a7%a3%e6%9e%90%e7%89%88","status":"publish","type":"post","link":"http:\/\/43.139.99.192\/index.php\/2025\/09\/11\/java%e9%9d%a2%e8%af%95-%e4%bb%a3%e7%a0%81%e8%a7%a3%e6%9e%90%e7%89%88\/","title":{"rendered":"Java\u9762\u8bd5–\u4ee3\u7801\u89e3\u6790\u7248"},"content":{"rendered":"\n

\u4e00.Java\u57fa\u7840<\/strong><\/p>\n\n\n\n

\u57fa\u7840\u6982\u5ff5\u4e0e\u5e38\u8bc6Java\u8bed\u8a00\u6709\u54ea\u4e9b\u7279\u70b9\uff1a<\/strong><\/p>\n\n\n\n

1.\u9762\u5411\u5bf9\u8c61\uff1a\u652f\u6301\u5c01\u88c5\uff0c\u7ee7\u627f\u548c\u591a\u6001\u4e09\u5927\u7279\u6027\uff1b\u4ee3\u7801\u4ee5\u7c7b\u548c\u5bf9\u8c61\u4e3a\u5355\u4f4d<\/p>\n\n\n\n

public class Animal {\n    public void sound() {\n        System.out.println(\"\u52a8\u7269\u53d1\u51fa\u58f0\u97f3\");\n    }\n}\n\npublic class Dog extends Animal {\n    @Override\n    public void sound() {\n        System.out.println(\"\u6c6a\u6c6a\u6c6a\");\n    }\n}\n<\/code><\/pre>\n\n\n\n
2.\u5e73\u53f0\u65e0\u5173\u6027<\/p>\n\n\n\n
3.\u5f3a\u7c7b\u578b\u8bed\u8a00<\/p>\n\n\n\n
4.\u81ea\u52a8\u5185\u5b58\u7ba1\u7406<\/p>\n\n\n\n
5.\u591a\u7ebf\u7a0b\u652f\u6301\uff1a\u5185\u7f6e\u5bf9\u591a\u7ebf\u7a0b\u7f16\u7a0b\u7684\u652f\u6301\uff1b\u901a\u8fc7Thread\u7c7b\u6216\u8005Runnable\u63a5\u53e3\u521b\u5efa\u7ebf\u7a0b\uff1b\u63d0\u4f9bsynchronized\u548clock\u5b9e\u73b0\u540c\u6b65\u673a\u5236<\/p>\n\n\n\n
public class MyThread implements Runnable {\n    @Override\n    public void run() {\n        System.out.println(\"\u7ebf\u7a0b\u6b63\u5728\u6267\u884c\");\n    }\n}\n<\/code><\/pre>\n\n\n\n
JVM vs JDK vs JRE<\/strong><\/p>\n\n\n\n
JVM<\/strong><\/p>\n\n\n\n
java\u865a\u62df\u673a\u662f\u8fd0\u884cjava\u5b57\u8282\u7801\u7684\u865a\u62df\u673a\u3002\u5b57\u8282\u7801\u548c\u4e0d\u540c\u7cfb\u7edf\u7684JVM\u5b9e\u73b0\u662fjava\u8bed\u8a00\u201c\u4e00\u6b21\u7f16\u8bd1\uff0c\u968f\u5904\u53ef\u4ee5\u8fd0\u884c\u201d\u7684\u5173\u952e\u6240\u5728<\/p>\n\n\n\n
JDK\u548cjRE<\/strong><\/p>\n\n\n\n
JDK\u5b83\u662f\u529f\u80fd\u9f50\u5168\u7684javaSDk\uff0c\u662f\u63d0\u4f9b\u7ed9\u5f00\u53d1\u8005\u4f7f\u7528\uff0c\u80fd\u591f\u521b\u5efa\u548c\u7f16\u8bd1Java\u7a0b\u5e8f\u7684\u5f00\u53d1\u5957\u4ef6\u3002\u4ed6\u5305\u542bJRE\uff0c\u540c\u65f6\u8fd8\u5305\u542b\u4e86\u7f16\u8bd1 java \u6e90\u7801\u7684\u7f16\u8bd1\u5668 javac \u4ee5\u53ca\u4e00\u4e9b\u5176\u4ed6\u5de5\u5177\u6bd4\u5982 javadoc\uff08\u6587\u6863\u6ce8\u91ca\u5de5\u5177\uff09\u3001jdb\uff08\u8c03\u8bd5\u5668\uff09\u3001jconsole\uff08\u57fa\u4e8e JMX \u7684\u53ef\u89c6\u5316\u76d1\u63a7\u2f2f\u5177\uff09\u3001javap\uff08\u53cd\u7f16\u8bd1\u5de5\u5177\uff09\u7b49\u7b49\u3002<\/p>\n\n\n\n
JRE\uff08Java Runtime Environment\uff09 \u662f Java \u8fd0\u884c\u65f6\u73af\u5883\u3002\u5b83\u662f\u8fd0\u884c\u5df2\u7f16\u8bd1 Java \u7a0b\u5e8f\u6240\u9700\u7684\u6240\u6709\u5185\u5bb9\u7684\u96c6\u5408\uff0c\u4e3b\u8981\u5305\u62ec Java \u865a\u62df\u673a\uff08JVM\uff09\u3001Java \u57fa\u7840\u7c7b\u5e93\uff08Class Library\uff09\u3002<\/p>\n\n\n\n
\u4e5f\u5c31\u662f\u8bf4\uff0cJRE \u662f Java \u8fd0\u884c\u65f6\u73af\u5883\uff0c\u4ec5\u5305\u542b Java \u5e94\u7528\u7a0b\u5e8f\u7684\u8fd0\u884c\u65f6\u73af\u5883\u548c\u5fc5\u8981\u7684\u7c7b\u5e93\u3002\u800c JDK \u5219\u5305\u542b\u4e86 JRE\uff0c\u540c\u65f6\u8fd8\u5305\u62ec\u4e86 javac\u3001javadoc\u3001jdb\u3001jconsole\u3001javap \u7b49\u5de5\u5177\uff0c\u53ef\u4ee5\u7528\u4e8e Java \u5e94\u7528\u7a0b\u5e8f\u7684\u5f00\u53d1\u548c\u8c03\u8bd5\u3002\u5982\u679c\u9700\u8981\u8fdb\u884c Java \u7f16\u7a0b\u5de5\u4f5c\uff0c\u6bd4\u5982\u7f16\u5199\u548c\u7f16\u8bd1 Java \u7a0b\u5e8f\u3001\u4f7f\u7528 Java API \u6587\u6863\u7b49\uff0c\u5c31\u9700\u8981\u5b89\u88c5 JDK\u3002\u800c\u5bf9\u4e8e\u67d0\u4e9b\u9700\u8981\u4f7f\u7528 Java \u7279\u6027\u7684\u5e94\u7528\u7a0b\u5e8f\uff0c\u5982 JSP \u8f6c\u6362\u4e3a Java Servlet\u3001\u4f7f\u7528\u53cd\u5c04\u7b49\uff0c\u4e5f\u9700\u8981 JDK \u6765\u7f16\u8bd1\u548c\u8fd0\u884c Java \u4ee3\u7801\u3002\u56e0\u6b64\uff0c\u5373\u4f7f\u4e0d\u6253\u7b97\u8fdb\u884c Java \u5e94\u7528\u7a0b\u5e8f\u7684\u5f00\u53d1\u5de5\u4f5c\uff0c\u4e5f\u6709\u53ef\u80fd\u9700\u8981\u5b89\u88c5 JDK\u3002
<\/p>\n\n\n\n
\u4e0d\u8fc7\uff0c\u4ece JDK 9 \u5f00\u59cb\uff0c\u5c31\u4e0d\u9700\u8981\u533a\u5206 JDK \u548c JRE \u7684\u5173\u7cfb\u4e86\uff0c\u53d6\u800c\u4ee3\u4e4b\u7684\u662f\u6a21\u5757\u7cfb\u7edf\uff08JDK \u88ab\u91cd\u65b0\u7ec4\u7ec7\u6210 94 \u4e2a\u6a21\u5757\uff09+ jlinkopen in new window \u5de5\u5177 (\u968f Java 9 \u4e00\u8d77\u53d1\u5e03\u7684\u65b0\u547d\u4ee4\u884c\u5de5\u5177\uff0c\u7528\u4e8e\u751f\u6210\u81ea\u5b9a\u4e49 Java \u8fd0\u884c\u65f6\u6620\u50cf\uff0c\u8be5\u6620\u50cf\u4ec5\u5305\u542b\u7ed9\u5b9a\u5e94\u7528\u7a0b\u5e8f\u6240\u9700\u7684\u6a21\u5757) \u3002\u5e76\u4e14\uff0c\u4ece JDK 11 \u5f00\u59cb\uff0cOracle \u4e0d\u518d\u63d0\u4f9b\u5355\u72ec\u7684 JRE \u4e0b\u8f7d\u3002
<\/p>\n\n\n\n
\u4ec0\u4e48\u662f\u5b57\u8282\u7801\uff1f\u91c7\u7528\u5b57\u8282\u7801\u7684\u597d\u5904\u662f\u4ec0\u4e48\uff1f<\/strong><\/p>\n\n\n\n
\u5728Java\u4e2d\uff0cJVM\u53ef\u4ee5\u7406\u89e3\u7684\u4ee3\u7801\u5c31\u53eb\u505a\u5b57\u8282\u7801\uff08\u5373\u6269\u5c55\u540d\u4e3a.class\u7684\u6587\u4ef6\uff09\uff0c\u5b83\u4e0d\u9762\u5411\u4efb\u4f55\u7279\u5b9a\u7684\u5904\u7406\u5668\uff0c\u53ea\u9762\u5411\u865a\u62df\u673a\u3002Java \u8bed\u8a00\u901a\u8fc7\u5b57\u8282\u7801\u7684\u65b9\u5f0f\uff0c\u5728\u4e00\u5b9a\u7a0b\u5ea6\u4e0a\u89e3\u51b3\u4e86\u4f20\u7edf\u89e3\u91ca\u578b\u8bed\u8a00\u6267\u884c\u6548\u7387\u4f4e\u7684\u95ee\u9898\uff0c\u540c\u65f6\u53c8\u4fdd\u7559\u4e86\u89e3\u91ca\u578b\u8bed\u8a00\u53ef\u79fb\u690d\u7684\u7279\u70b9\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u9700\u8981\u683c\u5916\u6ce8\u610f\u7684\u662f .class->\u673a\u5668\u7801 \u8fd9\u4e00\u6b65\u3002\u5728\u8fd9\u4e00\u6b65 JVM \u7c7b\u52a0\u8f7d\u5668\u9996\u5148\u52a0\u8f7d\u5b57\u8282\u7801\u6587\u4ef6\uff0c\u7136\u540e\u901a\u8fc7\u89e3\u91ca\u5668\u9010\u884c\u89e3\u91ca\u6267\u884c\uff0c\u8fd9\u79cd\u65b9\u5f0f\u7684\u6267\u884c\u901f\u5ea6\u4f1a\u76f8\u5bf9\u6bd4\u8f83\u6162\u3002\u800c\u4e14\uff0c\u6709\u4e9b\u65b9\u6cd5\u548c\u4ee3\u7801\u5757\u662f\u7ecf\u5e38\u9700\u8981\u88ab\u8c03\u7528\u7684(\u4e5f\u5c31\u662f\u6240\u8c13\u7684\u70ed\u70b9\u4ee3\u7801)\uff0c\u6240\u4ee5\u540e\u9762\u5f15\u8fdb\u4e86 JIT\uff08Just in Time Compilation\uff09 \u7f16\u8bd1\u5668\uff0c\u800c JIT \u5c5e\u4e8e\u8fd0\u884c\u65f6\u7f16\u8bd1\u3002\u5f53 JIT \u7f16\u8bd1\u5668\u5b8c\u6210\u7b2c\u4e00\u6b21\u7f16\u8bd1\u540e\uff0c\u5176\u4f1a\u5c06\u5b57\u8282\u7801\u5bf9\u5e94\u7684\u673a\u5668\u7801\u4fdd\u5b58\u4e0b\u6765\uff0c\u4e0b\u6b21\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u3002\u800c\u6211\u4eec\u77e5\u9053\uff0c\u673a\u5668\u7801\u7684\u8fd0\u884c\u6548\u7387\u80af\u5b9a\u662f\u9ad8\u4e8e Java \u89e3\u91ca\u5668\u7684\u3002\u8fd9\u4e5f\u89e3\u91ca\u4e86\u6211\u4eec\u4e3a\u4ec0\u4e48\u7ecf\u5e38\u4f1a\u8bf4 Java \u662f\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5171\u5b58\u7684\u8bed\u8a00 \u3002
<\/p>\n\n\n\n
\u4e3a\u4ec0\u4e48\u8bf4java\u8bed\u8a00\u201c\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5e76\u5b58\u201d\uff1f<\/strong><\/p>\n\n\n\n
\u6211\u4eec\u53ef\u4ee5\u5c06\u9ad8\u7ea7\u7f16\u7a0b\u8bed\u8a00\u5b89\u88c5\u7a0b\u5e8f\u7684\u6267\u884c\u65b9\u5f0f\u5206\u4e3a\u4e24\u79cd\uff1a<\/p>\n\n\n\n
\u7f16\u8bd1\u578b\uff1a\u7f16\u8bd1\u578b\u8bed\u8a00open in new window \u4f1a\u901a\u8fc7\u7f16\u8bd1\u5668open in new window\u5c06\u6e90\u4ee3\u7801\u4e00\u6b21\u6027\u7ffb\u8bd1\u6210\u53ef\u88ab\u8be5\u5e73\u53f0\u6267\u884c\u7684\u673a\u5668\u7801\u3002\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u7f16\u8bd1\u8bed\u8a00\u7684\u6267\u884c\u901f\u5ea6\u6bd4\u8f83\u5feb\uff0c\u5f00\u53d1\u6548\u7387\u6bd4\u8f83\u4f4e\u3002\u5e38\u89c1\u7684\u7f16\u8bd1\u6027\u8bed\u8a00\u6709 C\u3001C++\u3001Go\u3001Rust \u7b49\u7b49\u3002<\/p>\n\n\n\n
\u89e3\u91ca\u578b\uff1a\u89e3\u91ca\u578b\u8bed\u8a00open in new window\u4f1a\u901a\u8fc7\u89e3\u91ca\u5668open in new window\u4e00\u53e5\u4e00\u53e5\u7684\u5c06\u4ee3\u7801\u89e3\u91ca\uff08interpret\uff09\u4e3a\u673a\u5668\u4ee3\u7801\u540e\u518d\u6267\u884c\u3002\u89e3\u91ca\u578b\u8bed\u8a00\u5f00\u53d1\u6548\u7387\u6bd4\u8f83\u5feb\uff0c\u6267\u884c\u901f\u5ea6\u6bd4\u8f83\u6162\u3002\u5e38\u89c1\u7684\u89e3\u91ca\u6027\u8bed\u8a00\u6709 Python\u3001JavaScript\u3001PHP \u7b49\u7b49\u3002<\/p>\n\n\n\n
\u4e3a\u4ec0\u4e48\u8bf4java\u8bed\u8a00\u201c\u7f16\u8bd1\u4e0e\u89e3\u91ca\u5e76\u5b58\u201d\uff1f\u8fd9\u662f\u56e0\u4e3a Java \u8bed\u8a00\u65e2\u5177\u6709\u7f16\u8bd1\u578b\u8bed\u8a00\u7684\u7279\u5f81\uff0c\u4e5f\u5177\u6709\u89e3\u91ca\u578b\u8bed\u8a00\u7684\u7279\u5f81\u3002\u56e0\u4e3a Java \u7a0b\u5e8f\u8981\u7ecf\u8fc7\u5148\u7f16\u8bd1\uff0c\u540e\u89e3\u91ca\u4e24\u4e2a\u6b65\u9aa4\uff0c\u7531 Java \u7f16\u5199\u7684\u7a0b\u5e8f\u9700\u8981\u5148\u7ecf\u8fc7\u7f16\u8bd1\u6b65\u9aa4\uff0c\u751f\u6210\u5b57\u8282\u7801\uff08.class \u6587\u4ef6\uff09\uff0c\u8fd9\u79cd\u5b57\u8282\u7801\u5fc5\u987b\u7531 Java \u89e3\u91ca\u5668\u6765\u89e3\u91ca\u6267\u884c\u3002<\/p>\n\n\n\n
java\u6709\u54ea\u4e9b\u6570\u636e\u7c7b\u578b<\/strong><\/p>\n\n\n\n
\u5b9a\u4e49<\/strong>\uff1aJava\u8bed\u8a00\u662f\u5f3a\u7c7b\u578b\u8bed\u8a00\uff0c\u5bf9\u4e8e\u6bcf\u4e00\u79cd\u6570\u636e\u90fd\u5b9a\u4e49\u4e86\u660e\u786e\u7684\u5177\u4f53\u7684\u6570\u636e\u7c7b \u578b\uff0c\u5728\u5185\u5b58\u4e2d\u5206\u914d\u4e86\u4e0d\u540c\u5927\u5c0f\u7684\u5185\u5b58\u7a7a\u95f4\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
java\u4e09\u5927\u7279\u6027<\/strong><\/p>\n\n\n\n
\u5c01\u88c5<\/p>\n\n\n\n
\u5b9a\u4e49<\/strong>\uff1a \u5c01\u88c5\u662f\u6307\u5c06\u5bf9\u8c61\u7684\u72b6\u6001\uff08\u5c5e\u6027\uff09\u548c\u884c\u4e3a\uff08\u65b9\u6cd5\uff09\u6346\u7ed1\u5728\u4e00\u8d77\uff0c\u5e76\u5bf9\u5916\u90e8\u9690\u85cf\u5bf9\u8c61\u7684\u5185\u90e8\u5b9e\u73b0\u7ec6\u8282\uff0c\u4ec5\u63d0\u4f9b\u516c\u5171\u7684\u8bbf\u95ee\u65b9\u5f0f\u3002\u901a\u8fc7\u5c01\u88c5\uff0c\u53ef\u4ee5\u4fdd\u62a4\u6570\u636e\u4e0d\u88ab\u5916\u90e8\u968f\u610f\u8bbf\u95ee\u548c\u4fee\u6539\uff0c\u63d0\u9ad8\u4ee3\u7801\u7684\u5b89\u5168\u6027\u548c\u53ef\u7ef4\u62a4\u6027\u3002<\/p>\n\n\n\n
\/\/ \u5b9a\u4e49\u4e00\u4e2a Person \u7c7b\nclass Person {\n    \/\/ \u79c1\u6709\u5c5e\u6027\uff0c\u5916\u90e8\u65e0\u6cd5\u76f4\u63a5\u8bbf\u95ee\n    private String name;\n    private int age;\n\n    \/\/ \u516c\u5171\u7684 getter \u65b9\u6cd5\uff0c\u7528\u4e8e\u83b7\u53d6 name \u5c5e\u6027\n    public String getName() {\n        return name;\n    }\n\n    \/\/ \u516c\u5171\u7684 setter \u65b9\u6cd5\uff0c\u7528\u4e8e\u8bbe\u7f6e name \u5c5e\u6027\n    public void setName(String name) {\n        this.name = name;\n    }\n\n    \/\/ \u516c\u5171\u7684 getter \u65b9\u6cd5\uff0c\u7528\u4e8e\u83b7\u53d6 age \u5c5e\u6027\n    public int getAge() {\n        return age;\n    }\n\n    \/\/ \u516c\u5171\u7684 setter \u65b9\u6cd5\uff0c\u7528\u4e8e\u8bbe\u7f6e age \u5c5e\u6027\n    public void setAge(int age) {\n        if (age >= 0) {\n            this.age = age;\n        } else {\n            System.out.println(\"\u5e74\u9f84\u4e0d\u80fd\u4e3a\u8d1f\u6570\");\n        }\n    }\n}\n\npublic class EncapsulationExample {\n    public static void main(String[] args) {\n        Person person = new Person();\n        \/\/ \u901a\u8fc7 setter \u65b9\u6cd5\u8bbe\u7f6e\u5c5e\u6027\u503c\n        person.setName(\"\u5f20\u4e09\");\n        person.setAge(25);\n        \/\/ \u901a\u8fc7 getter \u65b9\u6cd5\u83b7\u53d6\u5c5e\u6027\u503c\n        System.out.println(\"\u59d3\u540d: \" + person.getName());\n        System.out.println(\"\u5e74\u9f84: \" + person.getAge());\n    }\n}\n<\/code><\/pre>\n\n\n\n
\u89e3\u91ca\uff1a \u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0cPerson \u7c7b\u7684 name \u548c age \u5c5e\u6027\u88ab\u58f0\u660e\u4e3a private\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4eec\u53ea\u80fd\u5728 Person \u7c7b\u5185\u90e8\u88ab\u8bbf\u95ee\u3002\u5916\u90e8\u4ee3\u7801\u8981\u8bbf\u95ee\u548c\u4fee\u6539\u8fd9\u4e9b\u5c5e\u6027\uff0c\u5fc5\u987b\u901a\u8fc7\u516c\u5171\u7684 getter \u548c setter \u65b9\u6cd5\u3002\u8fd9\u6837\u53ef\u4ee5\u5bf9\u5c5e\u6027\u7684\u8bbf\u95ee\u8fdb\u884c\u63a7\u5236\uff0c\u4f8b\u5982\u5728 setAge \u65b9\u6cd5\u4e2d\uff0c\u6dfb\u52a0\u4e86\u5bf9\u5e74\u9f84\u7684\u5408\u6cd5\u6027\u68c0\u67e5\uff0c\u907f\u514d\u4e86\u975e\u6cd5\u6570\u636e\u7684\u8f93\u5165\u3002
<\/p>\n\n\n\n
\u7ee7\u627f<\/strong><\/p>\n\n\n\n
**\u5b9a\u4e49\uff1a**\u7ee7\u627f\u662f\u6307\u4e00\u4e2a\u7c7b\uff08\u5b50\u7c7b\uff09\u53ef\u4ee5\u7ee7\u627f\u53e6\u4e00\u4e2a\u7c7b\uff08\u7236\u7c7b\uff09\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u4ece\u800c\u5b9e\u73b0\u4ee3\u7801\u7684\u590d\u7528\u548c\u6269\u5c55\u3002\u5b50\u7c7b\u53ef\u4ee5\u62e5\u6709\u7236\u7c7b\u7684\u6240\u6709\u975e\u79c1\u6709\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u5e76\u4e14\u53ef\u4ee5\u6839\u636e\u9700\u8981\u6dfb\u52a0\u81ea\u5df1\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u6216\u8005\u91cd\u5199\u7236\u7c7b\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n
\/\/ \u5b9a\u4e49\u4e00\u4e2a\u7236\u7c7b Animal\nclass Animal {\n    \/\/ \u7236\u7c7b\u7684\u5c5e\u6027\n    protected String name;\n\n    \/\/ \u7236\u7c7b\u7684\u65b9\u6cd5\n    public void eat() {\n        System.out.println(name + \" \u6b63\u5728\u5403\u4e1c\u897f\");\n    }\n}\n\n\/\/ \u5b9a\u4e49\u4e00\u4e2a\u5b50\u7c7b Dog\uff0c\u7ee7\u627f\u81ea Animal \u7c7b\nclass Dog extends Animal {\n    \/\/ \u5b50\u7c7b\u7684\u65b9\u6cd5\n    public void bark() {\n        System.out.println(name + \" \u6b63\u5728\u6c6a\u6c6a\u53eb\");\n    }\n}\n\npublic class InheritanceExample {\n    public static void main(String[] args) {\n        Dog dog = new Dog();\n        \/\/ \u5b50\u7c7b\u53ef\u4ee5\u4f7f\u7528\u7236\u7c7b\u7684\u5c5e\u6027\n        dog.name = \"\u65fa\u8d22\";\n        \/\/ \u5b50\u7c7b\u53ef\u4ee5\u8c03\u7528\u7236\u7c7b\u7684\u65b9\u6cd5\n        dog.eat();\n        \/\/ \u5b50\u7c7b\u53ef\u4ee5\u8c03\u7528\u81ea\u5df1\u7684\u65b9\u6cd5\n        dog.bark();\n    }\n}\n<\/code><\/pre>\n\n\n\n
\u591a\u6001<\/strong><\/p>\n\n\n\n
\u5b9a\u4e49\uff1a<\/strong> \u591a\u6001\u662f\u6307\u540c\u4e00\u4e2a\u65b9\u6cd5\u8c03\u7528\u53ef\u4ee5\u6839\u636e\u5bf9\u8c61\u7684\u4e0d\u540c\u7c7b\u578b\u800c\u8868\u73b0\u51fa\u4e0d\u540c\u7684\u884c\u4e3a\u3002\u591a\u6001\u7684\u5b9e\u73b0\u4f9d\u8d56\u4e8e\u7ee7\u627f\u548c\u65b9\u6cd5\u91cd\u5199\uff0c\u901a\u8fc7\u7236\u7c7b\u5f15\u7528\u6307\u5411\u5b50\u7c7b\u5bf9\u8c61\uff0c\u5728\u8fd0\u884c\u65f6\u6839\u636e\u5b9e\u9645\u5bf9\u8c61\u7684\u7c7b\u578b\u6765\u8c03\u7528\u76f8\u5e94\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n
\/\/ \u5b9a\u4e49\u4e00\u4e2a\u7236\u7c7b Shape\nclass Shape {\n    public void draw() {\n        System.out.println(\"\u7ed8\u5236\u56fe\u5f62\");\n    }\n}\n\n\/\/ \u5b9a\u4e49\u4e00\u4e2a\u5b50\u7c7b Circle\uff0c\u7ee7\u627f\u81ea Shape \u7c7b\uff0c\u5e76\u91cd\u5199 draw \u65b9\u6cd5\nclass Circle extends Shape {\n    @Override\n    public void draw() {\n        System.out.println(\"\u7ed8\u5236\u5706\u5f62\");\n    }\n}\n\n\/\/ \u5b9a\u4e49\u4e00\u4e2a\u5b50\u7c7b Rectangle\uff0c\u7ee7\u627f\u81ea Shape \u7c7b\uff0c\u5e76\u91cd\u5199 draw \u65b9\u6cd5\nclass Rectangle extends Shape {\n    @Override\n    public void draw() {\n        System.out.println(\"\u7ed8\u5236\u77e9\u5f62\");\n    }\n}\n\npublic class PolymorphismExample {\n    public static void main(String[] args) {\n        \/\/ \u7236\u7c7b\u5f15\u7528\u6307\u5411\u5b50\u7c7b\u5bf9\u8c61\n        Shape circle = new Circle();\n        Shape rectangle = new Rectangle();\n\n        \/\/ \u8c03\u7528 draw \u65b9\u6cd5\uff0c\u6839\u636e\u5b9e\u9645\u5bf9\u8c61\u7684\u7c7b\u578b\u8868\u73b0\u51fa\u4e0d\u540c\u7684\u884c\u4e3a\n        circle.draw();\n        rectangle.draw();\n    }\n}\n<\/code><\/pre>\n\n\n\n
\u91cd\u8f7d\u548c\u91cd\u5199\u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
\u91cd\u5199<\/strong><\/p>\n\n\n\n
\u4ece\u5b57\u9762\u4e0a\u770b\uff0c\u91cd\u5199\u5c31\u662f\u91cd\u65b0\u5199\u4e00\u904d\u7684\u610f\u601d\u3002\u5176\u5b9e\u5c31\u662f\u5b50\u7c7b\u628a\u7236\u7c7b\u7684\u65b9\u6cd5\u91cd\u65b0\u5199\u4e00\u904d\u3002\u5b50\u7c7b\u7ee7\u627f\u4e86\u7236\u7c7b\u539f\u6709\u7684\u65b9\u6cd5\uff0c\u4f46\u6709\u65f6\u5b50\u7c7b\u4e0d\u60f3\u539f\u5c01\u4e0d\u52a8\u5730\u7ee7\u627f\u7236\u7c7b\u7684\u65b9\u6cd5\uff0c\u8fd9\u662f\u5c31\u53ef\u4ee5\u5728\u65b9\u6cd5\u540d\uff0c\u53c2\u6570\u5217\u8868\uff0c\u8fd4\u56de\u7c7b\u578b\uff08(\u9664\u8fc7\u5b50\u7c7b\u4e2d\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u662f\u7236\u7c7b\u4e2d\u65b9\u6cd5\u8fd4\u56de\u503c\u7684\u5b50\u7c7b\u65f6)\u90fd\u76f8\u540c\u7684\u60c5\u51b5\u4e0b\uff0c\u5bf9\u65b9\u6cd5\u4f53\u8fdb\u884c\u4fee\u6539\u6216\u91cd\u5199\uff0c\u8fd9\u5c31\u662f\u91cd\u5199\u3002\u4f46\u8981\u6ce8\u610f\u5b50\u7c7b\u51fd\u6570\u7684\u8bbf\u95ee\u4fee\u9970\u6743\u9650\u4e0d\u80fd\u4f4e\u4e8e\u7236\u7c7b\u7684\u3002<\/p>\n\n\n\n
public class Father {\n\n    public static void main(String[] args) {\n        \/\/ TODO Auto-generated method stub\n        Son s = new Son();\n        s.sayHello();\n    }\n\n    public void sayHello() {\n        System.out.println(\"Hello\");\n    }\n}\n\nclass Son extends Father{\n\n    @Override\n    public void sayHello() {\n    \u3001    \/\/ TODO Auto-generated method stub\n        System.out.println(\"hello by \");\n    }\n\n}\n<\/code><\/pre>\n\n\n\n
\u91cd\u5199\u603b\u7ed3<\/strong><\/p>\n\n\n\n
\u53d1\u751f\u5728\u7236\u7c7b\u548c\u5b50\u7c7b\u4e4b\u95f4<\/p>\n\n\n\n
\u65b9\u6cd5\u540d\uff0c\u53c2\u6570\u5217\u8868\uff0c\u8fd4\u56de\u7c7b\u578b\uff08\u9664\u8fc7\u5b50\u7c7b\u65b9\u6cd5\u4e2d\u7684\u8fd4\u56de\u7c7b\u578b\u662f\u7236\u7c7b\u8fd4\u56de\u7c7b\u578b\u7684\u5b50\u7c7b\uff09\u5fc5\u987b\u76f8\u540c<\/p>\n\n\n\n
\u8bbf\u95ee\u4fee\u9970\u7b26\u7684\u9650\u5236\u4e00\u5b9a\u8981\u5927\u4e8e\u88ab\u91cd\u5199\u65b9\u6cd5\u7684\u8bbf\u95ee\u4fee\u9970\u7b26<\/p>\n\n\n\n
\u91cd\u5199\u65b9\u6cd5\u4e00\u5b9a\u4e0d\u80fd\u629b\u51fa\u65b0\u7684\u68c0\u67e5\u5f02\u5e38\u6216\u8005\u6bd4\u91cd\u5199\u65b9\u6cd5\u66f4\u52a0\u5bbd\u6cdb\u7684\u68c0\u67e5\u578b\u5f02\u5e38<\/p>\n\n\n\n
\u91cd\u8f7d<\/strong><\/p>\n\n\n\n
\u5728\u4e00\u4e2a\u7c7b\u4e2d\uff0c\u540c\u540d\u7684\u65b9\u6cd5\u5982\u679c\u6709\u4e0d\u540c\u7684\u53c2\u6570\u5217\u8868\uff08\u53c2\u6570\u7c7b\u578b\u4e0d\u540c\uff0c\u53c2\u6570\u4e2a\u6570\u4e0d\u540c\u751a\u81f3\u662f\u53c2\u6570\u7684\u987a\u5e8f\u4e0d\u540c\uff09\u5219\u89c6\u4e3a\u91cd\u8f7d\u3002\u540c\u65f6\uff0c\u91cd\u8f7d\u5bf9\u8fd4\u56de\u7c7b\u578b\u6ca1\u6709\u8981\u6c42\uff0c\u53ef\u4ee5\u76f8\u540c\u4e5f\u53ef\u4ee5\u4e0d\u540c\uff0c\u4f46\u4e0d\u80fd\u901a\u8fc7\u8fd4\u56de\u7c7b\u578b\u662f\u5426\u76f8\u540c\u53bb\u5224\u65ad\u91cd\u8f7d<\/p>\n\n\n\n
public class Father {\n\n    public static void main(String[] args) {\n        \/\/ TODO Auto-generated method stub\n        Father s = new Father();\n        s.sayHello();\n        s.sayHello(\"wintershii\");\n\n    }\n\n    public void sayHello() {\n        System.out.println(\"Hello\");\n    }\n\n    public void sayHello(String name) {\n        System.out.println(\"Hello\" + \" \" + name);\n    }\n}\n<\/code><\/pre>\n\n\n\n
\u91cd\u8f7d\u603b\u7ed3<\/strong><\/p>\n\n\n\n
\u91cd\u8f7d\u662f\u4e00\u4e2a\u7c7b\u4e2d\u591a\u6001\u6027\u7684\u4e00\u79cd\u8868\u73b0<\/p>\n\n\n\n
\u91cd\u8f7d\u8981\u6c42\u540c\u540d\u65b9\u6cd5\u53c2\u6570\u5217\u8868\u4e0d\u540c\uff08\u53c2\u6570\u7c7b\u578b\uff0c\u53c2\u6570\u4e2a\u6570\u751a\u81f3\u662f\u53c2\u6570\u987a\u5e8f\uff09<\/p>\n\n\n\n
\u91cd\u8f7d\u7684\u65f6\u5019\uff0c\u8fd4\u56de\u503c\u7c7b\u578b\u53ef\u4ee5\u76f8\u540c\u4e5f\u53ef\u4ee5\u4e0d\u76f8\u540c\uff0c\u4e0d\u53ef\u4ee5\u4ee5\u8fd4\u56de\u503c\u7c7b\u578b\u53bb\u5224\u65ad\u4f5c\u4e3a\u91cd\u8f7d\u51fd\u6570\u7684\u6807\u51c6<\/p>\n\n\n\n
\u9762\u8bd5\u65f6\uff0c\u95ee\uff1a\u91cd\u8f7d\uff08Overload\uff09\u548c\u91cd\u5199\uff08Override\uff09\u7684\u533a\u522b\uff1f<\/strong><\/p>\n\n\n\n
\u7b54\uff1a\u65b9\u6cd5\u7684\u91cd\u8f7d\u548c\u91cd\u5199\u90fd\u662f\u5b9e\u73b0\u591a\u6001\u7684\u65b9\u5f0f\uff0c\u533a\u522b\u5728\u4e8e\u524d\u8005\u5b9e\u73b0\u7684\u662f\u7f16\u8bd1\u65f6\u7684\u591a\u6001\u6027\uff0c\u800c\u540e\u8005\u5b9e\u73b0\u7684\u662f\u8fd0\u884c\u65f6\u7684\u591a\u6001\u6027\u3002\u91cd\u8f7d\u53d1\u751f\u5728\u4e00\u4e2a\u7c7b\u4e2d\uff0c\u540c\u540d\u7684\u65b9\u6cd5\u5982\u679c\u6709\u4e0d\u540c\u7684\u53c2\u6570\u5217\u8868\uff08\u53c2\u6570\u7c7b\u578b\u4e0d\u540c\u3001\u53c2\u6570\u4e2a\u6570\u4e0d\u540c\u6216\u8005\u4e8c\u8005\u90fd\u4e0d\u540c\uff09\u5219\u89c6\u4e3a\u91cd\u8f7d\uff1b\u91cd\u5199\u53d1\u751f\u5728\u5b50\u7c7b\u4e0e\u7236\u7c7b\u4e4b\u95f4\uff0c\u91cd\u5199\u8981\u6c42\u5b50\u7c7b\u88ab\u91cd\u5199\u65b9\u6cd5\u4e0e\u7236\u7c7b\u88ab\u91cd\u5199\u65b9\u6cd5\u6709\u76f8\u540c\u7684\u53c2\u6570\u5217\u8868\uff0c\u6709\u517c\u5bb9\u7684\u8fd4\u56de\u7c7b\u578b\uff0c\u6bd4\u7236\u7c7b\u88ab\u91cd\u5199\u65b9\u6cd5\u66f4\u597d\u8bbf\u95ee\uff0c\u4e0d\u80fd\u6bd4\u7236\u7c7b\u88ab\u91cd\u5199\u65b9\u6cd5\u58f0\u660e\u66f4\u591a\u7684\u5f02\u5e38\uff08\u91cc\u6c0f\u4ee3\u6362\u539f\u5219\uff09\u3002\u91cd\u8f7d\u5bf9\u8fd4\u56de\u7c7b\u578b\u6ca1\u6709\u7279\u6b8a\u7684\u8981\u6c42\uff0c\u4e0d\u80fd\u6839\u636e\u8fd4\u56de\u7c7b\u578b\u8fdb\u884c\u533a\u5206\u3002
<\/p>\n\n\n\n
\u8bbf\u95ee\u4fee\u9970\u7b26public,private,protected,\u4ee5\u53ca\u4e0d\u5199\uff08\u9ed8\u8ba4\uff09\u65f6\u7684 \u533a\u522b<\/strong><\/p>\n\n\n\n
\u5b9a\u4e49<\/strong>\uff1aJava\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u8bbf\u95ee\u4fee\u9970\u7b26\u6765\u4fdd\u62a4\u5bf9\u7c7b\u3001\u53d8\u91cf\u3001\u65b9\u6cd5\u548c\u6784\u9020\u65b9\u6cd5\u7684\u8bbf \u95ee\u3002Java \u652f\u6301 4 \u79cd\u4e0d\u540c\u7684\u8bbf\u95ee\u6743\u9650\u3002<\/p>\n\n\n\n
private\uff1a\u5728\u540c\u4e00\u7c7b\u5185\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u65b9\u6cd5\uff0c\u53d8\u91cf\u3002\u6ce8\u610f\u4e0d\u80fd\u4fee\u9970\u7c7b\uff08\u5916\u90e8\u7c7b\uff09<\/p>\n\n\n\n
default:(\u5373\u7f3a\u7701\uff0c\u4ec0\u4e48\u4e5f\u4e0d\u5199\uff0c\u4e0d\u4f7f\u7528\u4efb\u4f55\u5173\u952e\u5b57\uff09\uff1a\u5728\u540c\u4e00\u5305\u5185\u53ef\u89c1\uff0c\u4e0d\u4f7f\u7528\u4efb\u4f55\u4fee\u9970\u7b26\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u7c7b\uff0c\u63a5\u53e3\uff0c\u53d8\u91cf\uff0c\u65b9\u6cd5\u3002<\/p>\n\n\n\n
protect\uff1a\u5bf9\u540c\u4e00\u5305\u5185\u7684\u7c7b\u548c\u6240\u6709\u5b50\u7c7b\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u53d8\u91cf\uff0c\u65b9\u6cd5\u3002\u6ce8\u610f\u4e0d\u80fd\u4fee\u9970\u7c7b\uff08\u5916\u90e8\u7c7b\uff09<\/p>\n\n\n\n
public\uff1a\u5bf9\u6240\u6709\u7c7b\u53ef\u89c1\u3002\u4f7f\u7528\u5bf9\u8c61\uff1a\u7c7b\uff0c\u63a5\u53e3\uff0c\u53d8\u91cf\uff0c\u65b9\u6cd5\u3002<\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
==\u4e0eequal\u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
==\u5bf9\u4e8e\u57fa\u672c\u7c7b\u578b\u548c\u5f15\u7528\u7c7b\u578b\u7684\u4f5c\u7528\u6548\u679c\u662f\u4e0d\u540c\u7684\uff1a\u5bf9\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\u6765\u8bf4\uff0c==\u6bd4\u8f83\u7684\u662f\u503c\uff1b\u5bf9\u4e8e\u5f15\u7528\u7c7b\u578b\u6765\u8bf4\uff0c==\u6bd4\u8f83\u7684\u662f\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\u3002<\/p>\n\n\n\n
\u56e0\u4e3ajava\u53ea\u6709\u503c\u4f20\u9012\uff0c\u6240\u4ee5\uff0c\u5bf9\u4e8e==\u6765\u8bf4\uff0c\u4e0d\u7ba1\u662f\u6bd4\u8f83\u57fa\u672c\u6570\u636e\u7c7b\u578b\u8fd8\u662f\u5f15\u7528\u6570\u636e\u7c7b\u578b\u7684\u53d8\u91cf\uff0c\u5176\u672c\u8d28\u6bd4\u8f83\u7684\u90fd\u662f\u503c\uff0c\u53ea\u662f\u5f15\u7528\u7c7b\u578b\u53d8\u91cf\u5b58\u7684\u503c\u662f\u5bf9\u8c61\u7684\u5730\u5740<\/p>\n\n\n\n
equals()\u4e0d\u80fd\u7528\u4e8e\u5224\u65ad\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u53d8\u91cf\uff0c\u53ea\u80fd\u7528\u6765\u5224\u65ad\u4e24\u4e2a\u5bf9\u8c61\u662f\u5426\u76f8\u7b49\u3002equals()\u65b9\u6cd5\u5b58\u5728\u4e8eObject\u7c7b\u4e2d\uff0c\u800cObject\u7c7b\u662f\u6240\u6709\u7c7b\u7684\u76f4\u63a5\u6216\u95f4\u63a5\u7236\u7c7b\uff0c\u6240\u4ee5\u6240\u6709\u7684\u7c7b\u90fd\u6709equals()\u65b9\u6cd5<\/p>\n\n\n\n
equals()\u65b9\u6cd5\u5b58\u5728\u4e24\u79cd\u4f7f\u7528\u60c5\u51b5\uff1a<\/p>\n\n\n\n
\u7c7b\u6ca1\u6709\u91cd\u5199equals()\u65b9\u6cd5\uff1a\u901a\u8fc7equals()\u6bd4\u8f83\u8be5\u7c7b\u7684\u4e24\u4e2a\u5bf9\u8c61\u65f6\uff0c\u7b49\u4ef7\u4e8e\u901a\u8fc7\u201c==\u201d\u6bd4\u8f83\u8fd9\u4e24\u4e2a\u5bf9\u8c61\uff0c\u4f7f\u7528\u7684\u9ed8\u8ba4\u662fObject\u7c7bequals()\u65b9\u6cd5<\/p>\n\n\n\n
\u7c7b\u91cd\u5199\u4e86equals()\u65b9\u6cd5\uff1a\u4e00\u822c\u6211\u4eec\u91cd\u5199equals()\u65b9\u6cd5\u6765\u6bd4\u8f83\u4e24\u4e2a\u5bf9\u8c61\u4e2d\u7684\u5c5e\u6027\u662f\u5426\u76f8\u7b49\uff1b\u82e5\u4ed6\u4eec\u7684\u5c5e\u6027\u76f8\u7b49\uff0c\u5219\u8fd4\u56detrue<\/p>\n\n\n\n
String a = new String(\"ab\"); \/\/ a \u4e3a\u4e00\u4e2a\u5f15\u7528\nString b = new String(\"ab\"); \/\/ b\u4e3a\u53e6\u4e00\u4e2a\u5f15\u7528,\u5bf9\u8c61\u7684\u5185\u5bb9\u4e00\u6837\nString aa = \"ab\"; \/\/ \u653e\u5728\u5e38\u91cf\u6c60\u4e2d\nString bb = \"ab\"; \/\/ \u4ece\u5e38\u91cf\u6c60\u4e2d\u67e5\u627e\nSystem.out.println(aa == bb);\/\/ true\nSystem.out.println(a == b);\/\/ false\nSystem.out.println(a.equals(b));\/\/ true\nSystem.out.println(42 == 42.0);\/\/ true\n\n<\/code><\/pre>\n\n\n\n
String \u4e2d\u7684 equals \u65b9\u6cd5\u662f\u88ab\u91cd\u5199\u8fc7\u7684\uff0c\u56e0\u4e3a Object \u7684 equals \u65b9\u6cd5\u662f\u6bd4\u8f83\u7684\u5bf9\u8c61\u7684\u5185\u5b58\u5730\u5740\uff0c\u800c String \u7684 equals \u65b9\u6cd5\u6bd4\u8f83\u7684\u662f\u5bf9\u8c61\u7684\u503c\u3002<\/p>\n\n\n\n
public boolean equals(Object anObject) {\n    if (this == anObject) {\n        return true;\n    }\n    if (anObject instanceof String) {\n        String anotherString = (String)anObject;\n        int n = value.length;\n        if (n == anotherString.value.length) {\n            char v1[] = value;\n            char v2[] = anotherString.value;\n            int i = 0;\n            while (n-- != 0) {\n                if (v1[i] != v2[i])\n                    return false;\n                i++;\n            }\n            return true;\n        }\n    }\n    return false;\n}\n\n<\/code><\/pre>\n\n\n\n
hashCode() \u6709\u4ec0\u4e48\u7528\uff1f<\/strong><\/p>\n\n\n\n
hashCode() \u7684\u4f5c\u7528\u662f\u83b7\u53d6\u54c8\u5e0c\u7801\uff08int \u6574\u6570\uff09\uff0c\u4e5f\u79f0\u4e3a\u6563\u5217\u7801\u3002\u8fd9\u4e2a\u54c8\u5e0c\u7801\u7684\u4f5c\u7528\u662f\u786e\u5b9a\u8be5\u5bf9\u8c61\u5728\u54c8\u5e0c\u8868\u4e2d\u7684\u7d22\u5f15\u4f4d\u7f6e\u3002<\/p>\n\n\n\n
&\u548c&&\u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
\u7528\u6cd5<\/strong>\uff1a\u3000&&\u548c&\u90fd\u662f\u8868\u793a \u4e0e
\u533a\u522b\u662f<\/strong>\uff1a&&\u82e5\u7b2c\u4e00\u4e2a\u6761\u4ef6\u4e0d\u6ee1\u8db3\uff0c\u540e\u9762\u6761\u4ef6\u5c31\u4e0d\u518d\u5224\u65ad\u3002\u800c&\u8981\u5bf9\u6240\u6709\u7684\u6761\u4ef6\u90fd\u8fdb\u884c\u5224\u65ad
\u8fd4\u56de\u503c<\/strong>\uff1atrue\/false<\/p>\n\n\n\n
| \u548c || \u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
\u7528\u6cd5<\/strong>\uff1a|| \u548c | \u90fd\u662f\u8868\u793a \u6216
\u533a\u522b<\/strong>\uff1a || \u82e5\u7b2c\u4e00\u4e2a\u6761\u4ef6\u6ee1\u8db3\uff0c\u540e\u9762\u6761\u4ef6\u5c31\u4e0d\u518d\u5224\u65ad\u3002\u800c | \u8981\u5bf9\u6240\u6709\u7684\u6761\u4ef6\u90fd\u8fdb\u884c\u5224\u65ad
\u8fd4\u56de\u503c<\/strong>\uff1atrue\/false<\/p>\n\n\n\n
String\u3001StringBuffer\u3001StringBuilder\u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
\"\"<\/div><\/figure>\n\n\n\n
\u4e09\u8005\u5171\u540c\u4e4b\u5904:\u90fd\u662ffinal\u7c7b,\u4e0d\u5141\u8bb8\u88ab\u7ee7\u627f\uff0c\u4e3b\u8981\u662f\u4ece\u6027\u80fd\u548c\u5b89\u5168\u6027\u4e0a\u8003\u8651\u7684\uff0c\u56e0\u4e3a\u8fd9\u51e0\u4e2a\u7c7b\u90fd\u662f\u7ecf\u5e38\u88ab\u4f7f\u7528\u7740\uff0c\u4e14\u8003\u8651\u5230\u9632\u6b62\u5176\u4e2d\u7684\u53c2\u6570\u88ab\u53c2\u6570\u4fee\u6539\u5f71\u54cd\u5230\u5176\u4ed6\u7684\u5e94\u7528\u3002<\/p>\n\n\n\n
StringBuffer\u662f\u7ebf\u7a0b\u5b89\u5168\uff0c\u53ef\u4ee5\u4e0d\u9700\u8981\u989d\u5916\u7684\u540c\u6b65\u7528\u4e8e\u591a\u7ebf\u7a0b\u4e2d;
StringBuilder\u662f\u975e\u540c\u6b65,\u8fd0\u884c\u4e8e\u591a\u7ebf\u7a0b\u4e2d\u5c31\u9700\u8981\u4f7f\u7528\u7740\u5355\u72ec\u540c\u6b65\u5904\u7406\uff0c\u4f46\u662f\u901f\u5ea6\u5c31\u6bd4StringBuffer\u5feb\u591a\u4e86;
StringBuffer\u4e0eStringBuilder\u4e24\u8005\u5171\u540c\u4e4b\u5904:\u53ef\u4ee5\u901a\u8fc7append\u3001indert\u8fdb\u884c\u5b57\u7b26\u4e32\u7684\u64cd\u4f5c\u3002
String\u5b9e\u73b0\u4e86\u4e09\u4e2a\u63a5\u53e3:Serializable\u3001Comparable\u3001CarSequence
<\/p>\n\n\n\n
\u6267\u884c\u901f\u5ea6\u7531\u5feb\u5230\u6162\uff1aStringBuilder > StringBuffer > String<\/p>\n\n\n\n
    \n
  • \u5982\u679c\u8981\u64cd\u4f5c\u5c11\u91cf\u7684\u6570\u636e\u7528 String\uff1b<\/li>\n\n\n\n
  • \u591a\u7ebf\u7a0b\u64cd\u4f5c\u5b57\u7b26\u4e32\u7f13\u51b2\u533a\u4e0b\u64cd\u4f5c\u5927\u91cf\u6570\u636e StringBuffer\uff1b<\/li>\n\n\n\n
  • \u5355\u7ebf\u7a0b\u64cd\u4f5c\u5b57\u7b26\u4e32\u7f13\u51b2\u533a\u4e0b\u64cd\u4f5c\u5927\u91cf\u6570\u636e StringBuilder\u3002<\/li>\n<\/ul>\n\n\n\n
    \u53cd\u5c04<\/strong><\/p>\n\n\n\n
    \u5b9a\u4e49\uff1a\u5728\u8fd0\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5bf9\u4e8e\u4efb\u4f55\u4e00\u4e2a\u7c7b\u90fd\u80fd\u83b7\u53d6\u5b83\u7684\u5c5e\u6027\u548c\u65b9\u6cd5\uff0c\u4efb\u4f55\u4e00\u4e2a\u5bf9\u8c61\u90fd\u80fd\u8c03\u7528\u5176\u65b9\u6cd5\uff0c\u52a8\u6001\u83b7\u53d6\u4fe1\u606f\u548c\u52a8\u6001\u8c03\u7528\uff0c\u5c31\u662f\u53cd\u5c04<\/p>\n\n\n\n
    java\u83b7\u53d6\u53cd\u5c04\u7684\u4e09\u79cd\u65b9\u6cd5\uff1a<\/strong><\/p>\n\n\n\n
    \u901a\u8fc7new\u5bf9\u8c61\u5b9e\u73b0\u53cd\u5c04\u673a\u5236<\/p>\n\n\n\n
    \u901a\u8fc7\u8def\u5f84\u5b9e\u73b0\u53cd\u5c04\u673a\u5236<\/p>\n\n\n\n
    \u901a\u8fc7\u7c7b\u540d\u5b9e\u73b0\u53cd\u5c04\u673a\u5236<\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u548c\u63a5\u53e3\u7684\u533a\u522b<\/strong><\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u53ea\u80fd\u5355\u7ee7\u627f\uff0c\u63a5\u53e3\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a<\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u6709\u6784\u9020\u65b9\u6cd5\uff0c\u63a5\u53e3\u6ca1\u6709\u6784\u9020\u65b9\u6cd5<\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u53ef\u4ee5\u6709\u5b9e\u4f8b\u53d8\u91cf\uff0c\u63a5\u53e3\u4e2d\u6ca1\u6709\u5b9e\u4f8b\u53d8\u91cf\uff0c\u6709\u5e38\u91cf<\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u53ef\u4ee5\u5305\u542b\u975e\u62bd\u8c61\u65b9\u6cd5\uff0c\u63a5\u53e3\u5728java7\u4e4b\u524d\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u62bd\u8c61\u7684\uff0cjava8\u4e4b\u540e\u53ef\u4ee5\u5305\u542b\u975e\u62bd\u8c61\u65b9\u6cd5<\/p>\n\n\n\n
    \u62bd\u8c61\u7c7b\u4e2d\u65b9\u6cd5\u53ef\u4ee5\u662f\u4efb\u610f\u4fee\u9970\u7b26\uff0c\u63a5\u53e3\u4e2djava8\u4e4b\u524d\u90fd\u662fpublic\uff0cjava9\u652f\u6301private<\/p>\n\n\n\n
    \u5c0f\u8bb0\uff1a\u666e\u901a\u7c7b\u662f\u4eb2\u7239\uff0c\u624b\u628a\u624b\u6559\u4f60\u600e\u4e48\u5b66\uff0c\u62bd\u8c61\u7c7b\uff08\u591a\u4e2a\u7c7b\u5177\u6709\u60f3\u76f8\u540c\u7684\u4e1c\u897f\uff0c\u62ff\u51fa\u6765\u653e\u62bd\u8c61\u7c7b\uff09\u662f\u5e08\u5085\uff0c\u6559\u4f60\u4e00\u90e8\u5206\u79d8\u7c4d\uff0c\u7136\u540e\u544a\u8bc9\u4f60\u600e\u4e48\u5b66\u3002\u63a5\u53e3\uff08\u89c4\u8303\u4e86\u67d0\u4e9b\u884c\u4e3a\uff09\u662f\u5e72\u7239\uff0c\u53ea\u7ed9\u4f60\u79d8\u7c4d\uff0c\u600e\u4e48\u5b66\u5168\u9760\u4f60<\/p>\n\n\n\n
    Error\u548cException\u6709\u4ec0\u4e48\u533a\u522b<\/strong><\/p>\n\n\n\n
    Error\uff1a\u7a0b\u5e8f\u65e0\u6cd5\u5904\u7406\uff0c\u6bd4\u8f83\u4e25\u91cd\u7684\u95ee\u9898\uff0c\u7a0b\u5e8f\u4f1a\u7acb\u5373\u5d29\u6e83\uff0cjvm\u505c\u6b62\u8fd0\u884c<\/p>\n\n\n\n
    Exception\uff1a\u7a0b\u5e8f\u672c\u8eab\u53ef\u4ee5\u5904\u7406\uff08\u5411\u4e0a\u629b\u51fa\u6216\u8005\u6355\u83b7\uff09\u3002\u7f16\u8bd1\u65f6\u5f02\u5e38\u548c\u8fd0\u884c\u65f6\u5f02\u5e38<\/p>\n\n\n\n
    final\u5173\u952e\u5b57\u6709\u54ea\u4e9b\u7528\u6cd5\uff1f<\/strong><\/p>\n\n\n\n
    \u4fee\u9970\u7c7b\uff1a\u4e0d\u80fd\u88ab\u7ee7\u627f<\/p>\n\n\n\n
    \u4fee\u9970\u65b9\u6cd5\uff1a\u4e0d\u80fd\u88ab\u91cd\u5199<\/p>\n\n\n\n
    \u4fee\u9970\u53d8\u91cf\uff1a\u58f0\u660e\u65f6\u7ed9\u5b9a\u521d\u59cb\u503c\uff0c\u53ea\u80fd\u8bfb\u53d6\u4e0d\u80fd\u4fee\u6539\u3002\u5982\u679c\u662f\u5bf9\u8c61\u5f15\u7528\u4e0d\u80fd\u6539\uff0c\u4f46\u662f\u5bf9\u8c61\u7684\u5c5e\u6027\u53ef\u4ee5\u4fee\u6539<\/p>\n\n\n\n
    \u7528\u6700\u6709\u6548\u7387\u7684\u65b9\u6cd5\u8ba1\u7b97 2 \u4e58\u4ee5 8<\/strong><\/p>\n\n\n\n
    2 << 3\uff08\u5de6\u79fb 3 \u4f4d\u76f8\u5f53\u4e8e\u4e58\u4ee5 2 \u7684 3 \u6b21\u65b9\uff0c\u53f3\u79fb 3 \u4f4d\u76f8\u5f53\u4e8e\u9664\u4ee5 2 \u7684 3 \u6b21 \u65b9\uff09\u3002<\/p>\n\n\n\n
    final\u3001finally\u3001finalize\u533a\u522b<\/strong><\/p>\n\n\n\n
    final\u53ef\u4ee5\u4fee\u9970\u7c7b\uff0c\u53d8\u91cf\uff0c\u65b9\u6cd5\uff1b\u4fee\u9970\u7c7b\u8868\u793a\u8be5\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\uff0c\u4fee\u9970\u65b9\u6cd5\u8868\u793a\u8be5\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199\uff0c\u4fee\u9970\u53d8\u91cf\u8868\u793a\u8be5\u53d8\u91cf\u662f\u4e00\u4e2a\u5e38\u91cf\u4e0d\u80fd\u88ab\u91cd\u65b0\u8d4b\u503c<\/p>\n\n\n\n
    finally\u4e00\u822c\u4f5c\u7528\u5728try-catch\u4ee3\u7801\u5757\u4e2d\uff0c\u5728\u5904\u7406\u5f02\u5e38\u7684\u65f6\u5019\uff0c\u901a\u5e38\u6211\u4eec\u5c06\u4e00\u5b9a\u8981\u6267\u884c\u7684\u4ee3\u7801\u65b9\u6cd5finally\u4ee3\u7801\u5757\u4e2d\uff0c\u8868\u793a\u4e0d\u7ba1\u662f\u5426\u51fa\u73b0\u5f02\u5e38\uff0c\u8be5\u4ee3\u7801\u5757\u90fd\u4f1a\u6267\u884c\uff0c\u4e00\u822c\u7528\u6765\u5b58\u653e\u4e00\u4e9b\u5173\u95ed\u8d44\u6e90\u7684\u4ee3\u7801<\/p>\n\n\n\n
    finalize\u662f\u4e00\u4e2a\u65b9\u6cd5\uff0c\u5c5e\u4e8eObject\u7c7b\u7684\u4e00\u4e2a\u65b9\u6cd5\uff0c\u800cObject\u7c7b\u662f\u6240\u6709\u7c7b\u7684\u7236\u7c7b\uff0c\u8be5\u65b9\u6cd5\u4e00\u822c\u7531\u5783\u573e\u56de\u6536\u5668\u6765\u8c03\u7528\uff0c\u5f53\u6211\u4eec\u8c03\u7528System.gc()\u65b9\u6cd5\u7684\u65f6\u5019\uff0c\u7531\u5783\u573e\u56de\u6536\u5668\u8c03\u7528finalize(),\u56de\u6536\u5783\u573e\uff0c\u4e00\u4e2a\u5bf9\u8c61\u662f\u5426\u53ef\u56de\u6536\u7684\u6700\u540e\u5224\u65ad<\/p>\n\n\n\n
    this\u5173\u952e\u5b57\u7684\u7528\u6cd5<\/strong><\/p>\n\n\n\n
    this\u662f\u81ea\u8eab\u7684\u4e00\u4e2a\u5bf9\u8c61\uff0c\u4ee3\u8868\u5bf9\u8c61\u672c\u8eab\uff0c\u53ef\u4ee5\u7406\u89e3\u4e3a\uff1a\u6307\u5411\u5bf9\u8c61\u672c\u8eab\u7684\u4e00\u4e2a\u6307\u9488\u3002<\/p>\n\n\n\n
    this\u7684\u7528\u6cd5\u5728java\u4e2d\u5927\u4f53\u53ef\u4ee5\u5206\u4e3a3\u79cd\uff1a<\/p>\n\n\n\n
    \u666e\u901a\u7684\u76f4\u63a5\u5f15\u7528\uff0cthis\u76f8\u5f53\u4e8e\u662f\u6307\u5411\u5f53\u524d\u5bf9\u8c61\u672c\u8eab<\/p>\n\n\n\n
    \u5f62\u53c2\u4e0e\u6210\u5458\u540d\u5b57\u91cd\u540d\uff0c\u7528this\u6765\u533a\u5206<\/p>\n\n\n\n
    \u5f15\u7528\u672c\u7c7b\u7684\u6784\u9020\u51fd\u6570<\/p>\n\n\n\n
    <\/p>\n","protected":false},"excerpt":{"rendered":"
    \u4e00.Java\u57fa\u7840 \u57fa\u7840\u6982\u5ff5\u4e0e\u5e38\u8bc6Java\u8bed\u8a00\u6709\u54ea\u4e9b\u7279\u70b9\uff1a 1.\u9762\u5411\u5bf9\u8c61\uff1a\u652f\u6301\u5c01\u88c5\uff0c\u7ee7\u627f\u548c\u591a\u6001\u4e09\u5927\u7279\u6027\uff1b\u4ee3\u7801\u4ee5\u7c7b […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-266","post","type-post","status-publish","format-standard","hentry","category-text"],"_links":{"self":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/266","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/comments?post=266"}],"version-history":[{"count":7,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/266\/revisions"}],"predecessor-version":[{"id":283,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/266\/revisions\/283"}],"wp:attachment":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/media?parent=266"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/categories?post=266"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/tags?post=266"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}