{"id":1020,"date":"2021-03-15T14:38:22","date_gmt":"2021-03-15T06:38:22","guid":{"rendered":"http:\/\/www.zyhcoding.club\/?p=1020"},"modified":"2022-03-28T16:02:41","modified_gmt":"2022-03-28T08:02:41","slug":"java%e5%88%9d%e7%ba%a7%e8%af%ad%e6%b3%95","status":"publish","type":"post","link":"http:\/\/www.zyhcoding.club\/index.php\/2021\/03\/15\/java%e5%88%9d%e7%ba%a7%e8%af%ad%e6%b3%95\/","title":{"rendered":"JAVA\u521d\u7ea7\u8bed\u6cd5"},"content":{"rendered":"

Java\u662f\u89e3\u91ca\u578b\u8bed\u8a00\u3002JVM\u4f1a\u5148\u628ajava\u6e90\u4ee3\u7801\u7f16\u8bd1\u6210\u5b57\u8282\u7801\uff0c\u82e5\u5728\u7f16\u8bd1\u8fc7\u7a0b\u4e2d\u65e0\u8bed\u6cd5\u9519\u8bef\uff0c\u6210\u529f\u751f\u6210\u5b57\u8282\u7801\u4e86\uff0c\u90a3\u4e48\u4ee3\u7801\u6267\u884c\u8d77\u6765\u5c31\u4f1a\u7c7b\u4f3cpython\u4e00\u6837\uff0c\u53ef\u80fd\u4f1a\u6267\u884c\u5230\u4e00\u534a\u51fa\u9519\u5361\u4f4f\u3002
\njava\u7a0b\u5e8f\u7684\u5165\u53e3\u662fmain\u51fd\u6570\uff0c\u51fd\u6570\u58f0\u660e\u5fc5\u987b\u4e3apublic static void main(String[] args)<\/code>\uff0c\u8be5\u51fd\u6570\u53ef\u4ee5\u5728\u4efb\u4f55\u4e00\u4e2a\u7c7b\u91cc\u9762\uff0c\u4e0e\u7c7b\u65e0\u5173\uff0c\u82e5main\u51fd\u6570\u5185\u9700\u8981\u8c03\u7528\u6240\u5728\u7c7b\u7684\u51fd\u6570\u6216\u8bbf\u95ee\u5b57\u6bb5\uff0c\u90a3\u4e48\u9700\u8981\u5b9e\u4f8b\u5316\u6240\u5728\u7c7b\uff0c\u6216\u8005\u6240\u8bbf\u95ee\u7684\u4e1c\u897f\u88ab\u4fee\u9970\u4e3a\u9759\u6001\u7684\u4e5f\u884c\u3002
\n\u5728\u547d\u4ee4\u884c\u8fd0\u884cJava\u7a0b\u5e8f\u65f6\uff0c\u5148\u7528javac<\/code>\u7f16\u8bd1\u6e90\u4ee3\u7801\u4e3aclass<\/code>\u5b57\u8282\u7801\uff0cjavac<\/code>\u662fjava complier<\/code>java\u7f16\u8bd1\u5668\u7684\u610f\u601d\uff0c\u5728\u4f7f\u7528java<\/code>\u6765\u8fd0\u884c\u5b57\u8282\u7801\u3002<\/p>\n

$javac Main.java\n$java Main<\/code><\/pre>\n
args<\/code>\u53c2\u6570\u53ef\u4ee5\u5728\u547d\u4ee4\u884c\u8fd0\u884cjava\u7a0b\u5e8f\u65f6\u8d4b\u503c\uff0c\u6bd4\u5982\uff1a$java test -version<\/code>\uff0c\u800c\u5728main\u51fd\u6570\u4e2d\u6709\u4ee5\u4e0b\u4ee3\u7801:<\/p>\n
public class test{\n    public static void main(String[] args) {\n        for (String arg:args)   if (arg.equals("-version"))\n            System.out.println("JDK15.0");\n    }\n}<\/code><\/pre>\n
\u90a3\u4e48\u8fd0\u884c\u7ed3\u679c\u4e3aJDK15.0<\/code>\u3002<\/p>\n
Java\u5b57\u8282\u7801 Bytecode<\/h5>\n
  C\/C++\u7f16\u8bd1\u5668\u628a\u6e90\u4ee3\u7801\u7f16\u8bd1\u6210\u6c47\u7f16\u4ee3\u7801\uff0cJava\u7f16\u8bd1\u5668\u628a\u6e90\u4ee3\u7801\u7f16\u8bd1\u6210\u5b57\u8282\u7801bytecode\u3002Java\u8de8\u5e73\u53f0\u5c31\u662f\u57fa\u4e8e\u76f8\u540c\u7684\u5b57\u8282\u7801\u89c4\u8303\u505a\u4e0d\u540c\u5e73\u53f0\u7684\u865a\u62df\u673a\uff0cJava\u7a0b\u5e8f\u7f16\u8bd1\u6210bytecode\u540e\u5c31\u53ef\u4ee5\u5728\u4e0d\u540c\u7684\u5e73\u53f0\u4e0a\u8dd1\u4e86\uff0c\u4e5f\u5c31\u662f\u8bf4\u5728\u4efb\u4f55\u5e73\u53f0\u4e0aJava\u6e90\u7801\u7f16\u8bd1\u540e\u751f\u6210\u7684\u5b57\u8282\u7801\u662f\u4e00\u6837\u7684\uff0c\u53ea\u9700\u5904\u7406\u5b57\u8282\u7801\u5728\u4e0d\u540c\u7684\u7cfb\u7edf\u4e0a\u7684\u5904\u7406\u673a\u5236\u5373\u53ef\u3002\u5b57\u8282\u7801\u662fJava\u7a0b\u5e8f\u7684\u4e2d\u95f4\u8868\u793a\u5f62\u5f0f\uff0c\u6b63\u5982\u6c47\u7f16\u7a0b\u5e8f\u662fC\u6216C++\u7a0b\u5e8f\u7684\u4e2d\u95f4\u8868\u793a\u4e00\u6837\u3002<\/p>\n
Java\u5305<\/h5>\n
\u4e3a\u4e86\u66f4\u597d\u7684\u7ec4\u7ec7\u7c7b\uff0cJava\u63d0\u4f9b\u4e86\u5305\u673a\u5236\u3002\u5305\u662f\u7c7b\u7684\u5bb9\u5668\uff0c\u5c31\u662f\u4e00\u4e2a\u7c7b\u5e93\uff0c\u7528\u4e8e\u5206\u9694\u7c7b\u540d\u7a7a\u95f4\u3002\u5982\u679c\u6ca1\u6709\u6307\u7528\u6765\u63d0\u4f9b\u5e94\u7528\u7a0b\u5e8f\u4e0e\u5f00\u53d1\u4eba\u5458\u57fa\u4e8e\u67d0\u8f6f\u4ef6\u6216\u786c\u4ef6\u5f97\u4ee5\u8bbf\u95ee\u7684\u4e00\u7ec4\u4f8b\u7a0b\uff0c\u800c\u53c8\u65e0\u9700\u8bbf\u95ee\u6e90\u7801\uff0c\u6216\u7406\u89e3\u5185\u90e8\u5de5\u4f5c\u673a\u5236\u7684\u7ec6\u8282\u3002\u5b9a\u5305\u540d\uff0c\u6240\u6709\u793a\u4f8b\u90fd\u5c5e\u4e8e\u4e00\u4e2a\u9ed8\u8ba4\u7684\u65e0\u540d\u5305\u3002Java\u4e2d\u7684\u5305\u4e00\u822c\u5305\u542b\u76f8\u5173\u7684\u7c7b\u3002Java\u5305\u7c7b\u5e93\u7531\u4e00\u7ec4\u652f\u6301\u7a0b\u5e8f\u5f00\u53d1\u7684\u7c7b\u7ec4\u6210\u3002\u4e00\u4e2a\u7f16\u8bd1\u5668\u6216\u5f00\u53d1\u73af\u5883\u4ee5\u4e00\u4e2a\u7c7b\u5e93\u4e3a\u57fa\u7840\u3002<\/p>\n
API<\/h5>\n
Application Programming Interface<\/code>\uff0c\u5e94\u7528\u7a0b\u5e8f\u63a5\u53e3\uff0c\u662f\u4e00\u4e9b\u9884\u5148\u5b9a\u4e49\u7684\u63a5\u53e3\uff0c\u6216\u6307\u8f6f\u4ef6\u7cfb\u7edf\u4e0d\u540c\u7ec4\u6210\u90e8\u5206\u8854\u63a5\u7684\u7ea6\u5b9a\u3002\u7528\u6765\u63d0\u4f9b\u5e94\u7528\u7a0b\u5e8f\u4e0e\u5f00\u53d1\u4eba\u5458\u57fa\u4e8e\u67d0\u8f6f\u4ef6\u6216\u786c\u4ef6\u5f97\u4ee5\u8bbf\u95ee\u7684\u4e00\u7ec4\u4f8b\u7a0b\uff0c\u800c\u53c8\u65e0\u9700\u8bbf\u95ee\u6e90\u7801\uff0c\u6216\u7406\u89e3\u5185\u90e8\u5de5\u4f5c\u673a\u5236\u7684\u7ec6\u8282\u3002<\/p>\n
Java\u57fa\u672c\u7c7b\u578b\u548c\u5305\u88c5\u7c7b<\/h5>\n
Java\u5305\u542b\u57fa\u672c\u7c7b\u578b\u548c\u5305\u88c5\u7c7b\uff0c\u5305\u88c5\u7c7b\u53ef\u4ee5\u6709\u5bf9\u8c61\uff0c\u901a\u8fc7new\u5173\u952e\u5b57\u6765\u521b\u5efa\u5bf9\u8c61\u5e76\u5b58\u50a8\u5728\u5806\u4e2d\uff0c\u5f15\u7528\u653e\u5728\u6808\u4e2d\uff0c\u901a\u8fc7\u5f15\u7528\u6765\u4f7f\u7528\u8be5\u5b9e\u4f8b\u3002\u57fa\u672c\u7c7b\u578b\u4e0d\u662f\u7c7b\uff0c\u57fa\u672c\u7c7b\u578b\u53ef\u4ee5\u76f4\u63a5\u58f0\u660e\uff0c\u521d\u59cb\u5316\uff0c\u8d4b\u503c\u4f7f\u7528\uff0c\u4e0d\u9700\u8981\u7528new\uff0c\u800c\u4e14\u5b58\u50a8\u5728\u6808\u4e2d\u800c\u4e0d\u662f\u5806\u4e2d\u3002\u5305\u88c5\u7c7b\u578b\u76f8\u5f53\u4e8e\u5c06\u57fa\u672c\u7c7b\u578b\u5305\u88c5\u8d77\u6765\u3002
\nJava\u4e2d\u67098\u4e2d\u57fa\u672c\u7c7b\u578b\uff1aboolean, byte -> short char -> int -> long -> float -> double <\/code><\/code>
\n1\u5b57\u8282\uff1abyte<\/code><\/code>
\n2\u5b57\u8282\uff1achar short<\/code><\/code>       \/\/Java\u4e2dchar\u5360\u4e24\u4e2a\u5b57\u8282\uff0c\u91c7\u7528unicode\u7f16\u7801\uff0cC++\u4e2dchar\u53601\u4e2a\uff0c\u91c7\u7528ASCII\u7f16\u7801\uff08Unicode=UTF-16\uff09
\n4\u5b57\u8282\uff1aint<\/code><\/code>
\n8\u5b57\u8282\uff1along float<\/code><\/code>
\nboolean\u6240\u5360\u5185\u5b58\u5927\u5c0f\u662f\u4e0d\u786e\u5b9a\u7684\u3002<\/p>\n
\u5305\u88c5\u7c7b\u5c31\u662f\u6240\u8c13\u7684\u7c7b\uff0c\u7c7b<\/strong>\u662f\u4e00\u4e2a\u6a21\u677f\uff0c\u5b83\u63cf\u8ff0\u4e00\u7c7b\u5bf9\u8c61\u7684\u884c\u4e3a\u548c\u72b6\u6001\u3002\u65b9\u6cd5<\/strong>\u5c31\u662f\u884c\u4e3a\uff0c\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u6709\u5f88\u591a\u65b9\u6cd5\uff0c\u5bf9\u5bf9\u8c61\u7684\u5b9e\u4f8b\u53d8\u91cf\u7684\u4fee\u6539\u90fd\u662f\u5728\u65b9\u6cd5\u4e2d\u8fdb\u884c\u7684\u3002\u5bf9\u8c61<\/strong>\u662f\u7c7b\u7684\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u662f\u5b9e\u9645\u5b58\u5728\u7684\uff0c\u4e0d\u662f\u6a21\u677f\uff0c\u6709\u72b6\u6001\u548c\u884c\u4e3a\u3002\u5b9e\u4f8b\u53d8\u91cf<\/strong>\u63cf\u8ff0\u4e00\u4e2a\u5bf9\u8c61\u7684\u72b6\u6001\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u72ec\u7279\u7684\u5b9e\u4f8b\u53d8\u91cf\u3002<\/p>\n
Java Object\u7c7b<\/h5>\n
Java Object \u7c7b\u662f\u6240\u6709\u7c7b\u7684\u7236\u7c7b\uff0c\u4e5f\u5c31\u662f\u8bf4 Java \u7684\u6240\u6709\u7c7b\u90fd\u7ee7\u627f\u4e86 Object\uff0c\u5b50\u7c7b\u53ef\u4ee5\u4f7f\u7528 Object \u7684\u6240\u6709\u65b9\u6cd5\u3002
\nObject \u7c7b\u4f4d\u4e8e java.lang \u5305\u4e2d\uff0c\u7f16\u8bd1\u65f6\u4f1a\u81ea\u52a8\u5bfc\u5165\uff0c\u6211\u4eec\u521b\u5efa\u4e00\u4e2a\u7c7b\u65f6\uff0c\u5982\u679c\u6ca1\u6709\u660e\u786e\u7ee7\u627f\u4e00\u4e2a\u7236\u7c7b\uff0c\u90a3\u4e48\u5b83\u5c31\u4f1a\u81ea\u52a8\u7ee7\u627f Object\uff0c\u6210\u4e3a Object \u7684\u5b50\u7c7b\u3002<\/p>\n
Object();   \/\/ \u521b\u5efa\u4e00\u4e2a\u65b0\u5bf9\u8c61<\/code><\/pre>\n
\u6570\u7ec4<\/h5>\n
[]\u8868\u793a\u6570\u7ec4\u7684\u610f\u601d
\n\u6570\u7ec4\u662f\u4e00\u4e2a\u91cd\u8981\u7684\u6570\u636e\u7ed3\u6784\uff0c\u9700\u8981\u4f7f\u7528new\u5173\u952e\u5b57\u6765\u7533\u8bf7\uff0c\u5b9a\u4e49\u3002\u4e5f\u53ef\u4ee5\u76f4\u63a5{}<\/code>\u521d\u59cb\u5316\u3002
\n\u6570\u7ec4\u662f\u5f15\u7528\u7c7b\u578b\uff0c\u672c\u8d28\u4e0a\u4e5f\u662f\u4e00\u4e2a\u7c7b\uff0c\u7ee7\u627f\u81eaObject\u7c7b\u3002\u53ef\u901a\u8fc7.length<\/code>\u83b7\u53d6\u6570\u7ec4\u7684\u957f\u5ea6\uff0c\u8fd9\u662f\u6570\u7ec4\u7684\u4e00\u4e2a\u5c5e\u6027\uff0cjava\u7f16\u8bd1\u5668\u5728\u7f16\u8bd1\u65f6\u52a0\u4e0a\u53bb\u7684\uff0c\u4e0d\u662f\u65b9\u6cd5\uff0c\u4e5f\u4e0d\u662f\u5b57\u6bb5\u3002java.util.Arrays<\/code>\u7c7b\u63d0\u4f9b\u80fd\u591f\u65b9\u4fbf\u64cd\u4f5c\u6570\u7ec4\u7684\u9759\u6001\u65b9\u6cd5\u3002<\/p>\n
int[] a = new int[size];\nString[][] s = new String[20][];\ns[0] = new String[30];\ns[0][0] = new String("hello world!");\n\/* \u5bf9\u4e8eString\u5bf9\u8c61\uff0c\u6700\u597d\u4f7f\u7528new String("hello world!")\u6765\u5b9a\u4e49\u6216\u8005\u521d\u59cb\u5316\uff0c\u5f53\u7136\u4e5f\u7b49\u4ef7\u4e8es[0][0] = "hello world!" *\/<\/code><\/pre>\n
\u5f53\u6570\u7ec4\u4f5c\u4e3a\u53c2\u6570\u65f6\uff0c\u4f20\u7684\u662f\u5f15\u7528\u3002\u6570\u7ec4\u662f\u5f15\u7528\u7c7b\u578b\u3002<\/p>\n
class TestIt\n{\n    public static void main ( String[] args )\n    {\n        int[] myArray = {1, 2, 3, 4, 5};\n        ChangeIt.doIt( myArray );\n        for(int j=0; j<myArray.length; j++)\n            System.out.print( myArray[j] + " " );\n        \/\/ output: 1 2 3 4 5\n    }\n}\nclass ChangeIt\n{\n    static void doIt( int[] z )\n    {\n        z = null ;\n    }\n}<\/code><\/pre>\n
\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\uff0cmyArray\u6307\u5411\u4e00\u4e2a\u6570\u7ec4{1, 2, 3, 4, 5}\uff0c\u8c03\u7528doIt\u51fd\u6570\u540e\uff0cmyArray\u4f5c\u4e3a\u5f15\u7528\u4f20\u53c2\uff0c\u76f8\u5f53\u4e8e\u521b\u5efa\u4e86\u4e00\u4e2a\u65b0\u7684\u5f15\u7528\uff0c\u6307\u5411\u7684\u4e1c\u897f\u548cmyArray\u6307\u5411\u7684\u662f\u4e00\u6837\u7684\uff0c\u53ef\u4ee5\u901a\u8fc7\u4e24\u4e2a\u5f15\u7528\u4efb\u610f\u4e00\u4e2a\u5bf9\u6307\u5411\u7684\u8fd9\u5757\u6570\u636e\u8fdb\u884c\u4fee\u6539\uff0c\u4f46\u662f\u5982\u679c\u53ea\u662f\u5c06\u5176\u4e2d\u4efb\u4f55\u4e00\u4e2a\u5f15\u7528\u6307\u5411\u522b\u7684\u5730\u65b9\u7684\u8bdd\uff0c\u5bf9\u539f\u6765\u7684\u6570\u636e\u662f\u4e0d\u8fdb\u884c\u6539\u53d8\u7684\u3002\u4e00\u5b9a\u6ce8\u610fmyArray\u548cz\u662f\u4e24\u4e2a\u5f15\u7528\uff0c\u6307\u5411\u4e00\u4e2a\u4e1c\u897f\uff0cz\u4e0d\u662fmyArray\u7684\u5f15\u7528\uff0cz\u6307\u5411\u4ec0\u4e48\u5730\u65b9\u4e0emyArray\u65e0\u5173\u3002
\njava.util.Arrays<\/code>\u63d0\u4f9b\u7684\u6570\u7ec4\u64cd\u4f5c\u65b9\u6cd5\uff1a<\/p>\n
import java.util.Arrays;\npublic static void fill(int[] a, int val);  \/\/ \u8d4b\u503c\u6570\u7ec4a\u5185\u6240\u6709\u5143\u7d20\u5185\u5bb9\u4e3aval\npublic static void sort(Object[] a);    \/\/\u6570\u7ec4\u6392\u5e8f\npublic static boolean equals(type[] a, type[] a2); \/\/\u5224\u65ad\u4e24\u6570\u7ec4\u662f\u5426\u76f8\u540c\npublic static int binarySearch(Object[] a, Object key); \/\/\u4e8c\u5206\u67e5\u627e\uff0c\u6570\u7ec4\u5fc5\u987b\u5df2\u7ecf\u6392\u597d\u5e8f\uff0c\u641c\u7d22\u6210\u529f\u8fd4\u56de\u4e0b\u6807\uff0c\u641c\u7d22\u5931\u8d25\u8fd4\u56de-1\n<\/code><\/pre>\n
Java \u4fee\u9970\u7b26<\/h5>\n
\u4fee\u9970\u7b26\u7528\u6765\u5b9a\u4e49\u7c7b\u3001\u65b9\u6cd5\u6216\u8005\u53d8\u91cf\uff0c\u901a\u5e38\u653e\u5728\u8bed\u53e5\u6700\u524d\u7aef\u3002Java\u8bed\u8a00\u7684\u4fee\u9970\u7b26\u4e3b\u8981\u5206\u4e3a\u4e24\u7c7b\uff1a\u8bbf\u95ee\u4fee\u9970\u7b26<\/strong>\u548c\u975e\u8bbf\u95ee\u4fee\u9970\u7b26<\/strong>\u3002
\n\u8bbf\u95ee\u63a7\u5236\u4fee\u9970\u7b26\uff1adefault<\/strong>, private<\/strong>, public<\/strong>, protected<\/strong>. \u5404\u79cd\u8bbf\u95ee\u4fee\u9970\u7b26\u7684\u8bbf\u95ee\u6743\u9650\u5982\u4e0b\uff1a
\n\"java\u8bbf\u95ee\u4fee\u9970\u7b26\u6743\u9650\"<\/p>\n
\u79c1\u6709\u8bbf\u95ee\u4fee\u9970\u7b26private<\/strong>\uff1a\u79c1\u6709\u8bbf\u95ee\u4fee\u9970\u7b26\u662f\u6700\u4e25\u683c\u7684\u8bbf\u95ee\u7ea7\u522b\uff0c\u6240\u4ee5\u88ab\u58f0\u660e\u4e3a private \u7684\u65b9\u6cd5\u3001\u53d8\u91cf\u548c\u6784\u9020\u65b9\u6cd5\u53ea\u80fd\u88ab\u6240\u5c5e\u7c7b\u8bbf\u95ee\uff0c\u5e76\u4e14\u7c7b\u548c\u63a5\u53e3\u4e0d\u80fd\u58f0\u660e\u4e3a private\u3002Private \u8bbf\u95ee\u4fee\u9970\u7b26\u7684\u4f7f\u7528\u4e3b\u8981\u7528\u6765\u9690\u85cf\u7c7b\u7684\u5b9e\u73b0\u7ec6\u8282\u548c\u4fdd\u62a4\u7c7b\u7684\u6570\u636e\u3002
\n\u5171\u6709\u8bbf\u95ee\u4fee\u9970\u7b26public<\/strong>\uff1a\u88ab\u58f0\u660e\u4e3a public \u7684\u7c7b\u3001\u65b9\u6cd5\u3001\u6784\u9020\u65b9\u6cd5\u548c\u63a5\u53e3\u80fd\u591f\u88ab\u4efb\u4f55\u5176\u4ed6\u7c7b\u8bbf\u95ee\u3002\u5982\u679c\u51e0\u4e2a\u76f8\u4e92\u8bbf\u95ee\u7684 public \u7c7b\u5206\u5e03\u5728\u4e0d\u540c\u7684\u5305\u4e2d\uff0c\u5219\u9700\u8981\u5bfc\u5165\u76f8\u5e94 public \u7c7b\u6240\u5728\u7684\u5305\u3002\u7531\u4e8e\u7c7b\u7684\u7ee7\u627f\u6027\uff0c\u7c7b\u6240\u6709\u7684\u516c\u6709\u65b9\u6cd5\u548c\u53d8\u91cf\u90fd\u80fd\u88ab\u5176\u5b50\u7c7b\u7ee7\u627f\u3002<\/p>\n
Java \u8fd0\u7b97\u7b26<\/h5>\n
Java\u8fd0\u7b97\u7b26\u4e3b\u8981\u5206\u4e3a\u8fd9\u51e0\u4e2a\uff1a\u7b97\u672f\u8fd0\u7b97\u7b26\u3001\u5173\u7cfb\u8fd0\u7b97\u7b26\u3001\u4f4d\u8fd0\u7b97\u7b26\u3001\u903b\u8f91\u8fd0\u7b97\u7b26\u3001\u8d4b\u503c\u8fd0\u7b97\u7b26\u3001\u5176\u4ed6\u8fd0\u7b97\u7b26<\/strong>\u3002
\n\u7b97\u6570\u8fd0\u7b97\u7b26\uff1a+ - * \/ % ++ -- <\/code><\/code>\uff0c\u5176\u4e2d\u81ea\u52a0\uff0c\u81ea\u51cf\u6709\u524d\u7f00\u548c\u540e\u7f00\u4e4b\u5206\u3002
\n\u5173\u7cfb\u8fd0\u7b97\u7b26\uff1a== != >= <= > <<\/code><\/code>
\n\u4f4d\u8fd0\u7b97\u7b26\uff1a& | ^ ~ << >> >>><\/code><\/code>
\n\u903b\u8f91\u8fd0\u7b97\u7b26\uff1a&& || !<\/code><\/code>
\n\u8d4b\u503c\u8fd0\u7b97\u7b26\uff1a= += -= *= \/= %= >>= <<= &= |= ^=<\/code><\/code>
\n\u6761\u4ef6\u8fd0\u7b97\u7b26\uff1ax = (expression)? value if true:value if false<\/code><\/code><\/p>\n
Java \u5faa\u73af\u7ed3\u6784<\/h5>\n
\u987a\u5e8f\u7ed3\u6784\u7684\u7a0b\u5e8f\u8bed\u53e5\u53ea\u80fd\u88ab\u6267\u884c\u4e00\u6b21\u3002\u5982\u679c\u60a8\u60f3\u8981\u540c\u6837\u7684\u64cd\u4f5c\u6267\u884c\u591a\u6b21,\uff0c\u5c31\u9700\u8981\u4f7f\u7528\u5faa\u73af\u7ed3\u6784\u3002
\nJava\u4e3b\u8981\u6709\u4e09\u79cd\u5faa\u73af\u7ed3\u6784\uff1awhile<\/strong>, do...while<\/strong>, for<\/strong>\u3002\u4e0d\u540c\u4e8eC++\u7684\u662f\uff0cJava\u91cc\u7684\u5faa\u73af\u7ed3\u6784\u662f\u53ef\u4ee5\u547d\u540d\u7684\uff0c\u7136\u540ebreak\uff0ccontinue<\/code><\/code>\u8bed\u53e5\u53ef\u4ee5\u9009\u62e9\u6027\u7684\u8df3\u51fa\u5177\u4f53\u54ea\u4e00\u5c42\u5faa\u73af\uff01<\/p>\n
first:while (expression is true){\n    \/\/statement;\n}\n\nsecond:do {\n    \/\/statement\n} while (expression is true);\n\nthird:for (init; boolean expression; upd statement) {\n    \/\/statement\n}\n\n\/\/Java\u589e\u5f3afor\u5faa\u73af\uff1a\u8868\u8fbe\u5f0f\u9700\u8981\u65f6\u6570\u7ec4\u7c7b\u578b\uff0c\u4e0d\u4f1a\u5bf9\u6570\u7ec4\u5185\u5143\u7d20\u505a\u51fa\u6539\u53d8\nfor (\u58f0\u660e\u8bed\u53e5 \uff1a \u8868\u8fbe\u5f0f) {\n    \/\/\n}<\/code><\/pre>\n
Java\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u548c\u5f15\u7528\u6570\u636e\u7c7b\u578b Java Number\u7c7b<\/h5>\n
Java\u662f\u5f3a\u7c7b\u578b\u8bed\u8a00\uff0c\u6240\u4ee5Java\u5bf9\u4e8e\u6570\u636e\u7c7b\u578b\u7684\u89c4\u8303\u4f1a\u76f8\u5bf9\u4e25\u683c\u3002\u6570\u636e\u7c7b\u578b\u5728\u8ba1\u7b97\u673a\u8bed\u8a00\u91cc\u9762\uff0c\u662f\u5bf9\u5185\u5b58\u4f4d\u7f6e\u7684\u4e00\u4e2a\u62bd\u8c61\u8868\u8fbe\u65b9\u5f0f\uff0c\u53ef\u4ee5\u7406\u89e3\u4e3a\u9488\u5bf9\u5185\u5b58\u7684\u4e00\u79cd\u62bd\u8c61\u7684\u8868\u8fbe\u65b9\u5f0f\u3002\u5185\u7f6e\u6570\u636e\u7c7b\u578b\uff0c\u4e5f\u5c31\u662f\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u5176\u503c\u662f\u5b58\u50a8\u5728\u5185\u5b58\u7684\u6808\u7a7a\u95f4\u7684\uff0c\u800c\u5f15\u7528\u7c7b\u578b\u7684\u5f15\u7528\u5b58\u653e\u5728\u6808\u7a7a\u95f4\uff0c\u5176\u503c\u662f\u5b58\u653e\u5728\u5806\u7a7a\u95f4\u7684\uff0c\u8fd9\u662f\u5185\u7f6e\u7c7b\u578b\u548c\u5f15\u7528\u7c7b\u578b\u6700\u5927\u7684\u533a\u522b\u3002\u5f15\u7528\u7c7b\u578b\u90fd\u7ee7\u627f\u81eaObject\u7c7b\u3002
\n\u5728\u4f5c\u4e3a\u51fd\u6570\u53c2\u6570\u8fdb\u884c\u4f20\u53c2\u65f6\uff0c\u57fa\u672c\u6570\u636e\u7c7b\u578b\u4f20\u7684\u662f\u5f62\u53c2\uff0c\u5373\u51fd\u6570\u91cc\u590d\u5236\u4e86\u4e00\u4efd\u4e00\u6a21\u4e00\u6837\u7684\u53d8\u91cf\uff0c\u5bf9\u539f\u6765\u7684\u53d8\u91cf\u4e0d\u4f1a\u505a\u51fa\u6539\u53d8\u3002\u800c\u5f15\u7528\u7c7b\u578b\u4f5c\u4e3a\u53c2\u6570\u65f6\uff0c\u6240\u8c03\u7528\u7684\u51fd\u6570\u91cc\u9762\u53ea\u4f1a\u590d\u5236\u4e00\u4efd\u4e00\u6a21\u4e00\u6837\u7684\u5f15\u7528\uff0c\u5f15\u7528\u6307\u5411\u7684\u5185\u5b58\u6240\u5b58\u653e\u7684\u4e1c\u897f\u662f\u4e0d\u4f1a\u590d\u5236\u7684\uff0c\u5373\u4f1a\u5bf9\u5176\u6307\u5411\u7684\u5185\u5bb9\u505a\u51fa\u5b9e\u8d28\u6027\u7684\u6539\u53d8\u3002<\/p>\n
\u5728\u5b9e\u9645\u5f00\u53d1\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u7ecf\u5e38\u4f1a\u9047\u5230\u9700\u8981\u4f7f\u7528\u5bf9\u8c61\uff0c\u800c\u4e0d\u662f\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u7684\u60c5\u5f62\u3002\u4e3a\u4e86\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\uff0cJava \u8bed\u8a00\u4e3a\u6bcf\u4e00\u4e2a\u5185\u7f6e\u6570\u636e\u7c7b\u578b\u63d0\u4f9b\u4e86\u5bf9\u5e94\u7684\u5305\u88c5\u7c7b\u3002\u6240\u6709\u7684\u5305\u88c5\u7c7b\uff08Integer\u3001Long\u3001Byte\u3001Double\u3001Float\u3001Short\uff09\u90fd\u662f\u62bd\u8c61\u7c7b Number \u7684\u5b50\u7c7b\u3002
\n\"\"<\/p>\n
\u7f16\u8bd1\u5668\u53ef\u4ee5\u628a\u5185\u7f6e\u7c7b\u578b\u88c5\u7bb1\u4e3a\u5305\u88c5\u7c7b\uff0c\u4e5f\u53ef\u4ee5\u628a\u4e00\u4e2a\u5bf9\u8c61\u62c6\u7bb1\u4e3a\u5185\u7f6e\u7c7b\u578b\u3002\u5305\u88c5\u7c7b\u548c\u5176\u5bf9\u5e94\u7684\u5185\u7f6e\u7c7b\u578b\u5728\u4f7f\u7528\u65b9\u9762\u65e0\u5dee\u5f02\u3002<\/p>\n
public class Test{\n\n   public static void main(String[] args){\n      Integer x = 5;\n      x =  x + 10;\n      System.out.println(x);     \/\/15\n   }\n}<\/code><\/pre>\n
x\u662f\u4e00\u4e2a\u5bf9\u8c61\uff0c\u88ab\u8d4b\u503c\u6574\u5f62\u6570\u503c\uff0c\u7f16\u8bd1\u5668\u4f1a\u5bf9x\u8fdb\u884c\u88c5\u7bb1\u3002\u4e3a\u4e86\u4f7fx\u80fd\u591f\u8fdb\u884c\u7b97\u672f\u8fd0\u7b97\uff0c\u4f1a\u5bf9x\u8fdb\u884c\u62c6\u7bb1\u3002
\n\u6240\u6709\u7684\u5305\u88c5\u7c7b\u90fd\u5c5e\u4e8eNumber\u7c7b\u3002<\/p>\n
Java\u57fa\u7840\u8f93\u5165\u548c\u8f93\u51fa<\/h5>\n
Java\u7684\u8f93\u51fa\u65b9\u6cd5\u5728System.out<\/code>\u7c7b\u91cc\u9762\u3002java\u8f93\u51fa\u4e5f\u652f\u6301\u7c7b\u4f3c\u4e8eC++\u8f93\u51fa\u7684\u683c\u5f0f\u4fee\u9970\u7b26\u3002<\/p>\n
public class Main {\n    public static void main(String[] args) {\n        double d = 3.1415926;\n        System.out.printf("%.2f\\n", d); \/\/ \u663e\u793a\u4e24\u4f4d\u5c0f\u65703.14\n        System.out.printf("%.4f\\n", d); \/\/ \u663e\u793a4\u4f4d\u5c0f\u65703.1416\n        System.out.println("END");    \/\/ \u8f93\u51fa\u4e00\u884c print line\u7684\u7f29\u5199\n    }\n}<\/code><\/pre>\n
\u8f93\u5165\u6bd4\u8f83\u9ebb\u70e6\uff0c\u5148\u5bfc\u5165java.util.Scanner<\/code>\u7c7b\uff0c\u7136\u540e\u521b\u5efa\u8be5\u7c7b\u5e76\u4f20\u5165System.in<\/code>\uff0cSystem.out<\/code>\u4ee3\u8868\u6807\u51c6\u8f93\u51fa\u6d41\uff0c\u800cSystem.in<\/code>\u4ee3\u8868\u6807\u51c6\u8f93\u5165\u6d41\u3002<\/p>\n
import java.util.Scanner;\n\npublic class Main {\n    public static void main(String[] args) {\n        Scanner scanner = new Scanner(System.in); \/\/ \u521b\u5efaScanner\u5bf9\u8c61\n        System.out.print("Input your name: "); \/\/ \u6253\u5370\u63d0\u793a\n        String name = scanner.nextLine(); \/\/ \u8bfb\u53d6\u4e00\u884c\u8f93\u5165\u5e76\u83b7\u53d6\u5b57\u7b26\u4e32\n        System.out.print("Input your age: "); \/\/ \u6253\u5370\u63d0\u793a\n        int age = scanner.nextInt(); \/\/ \u8bfb\u53d6\u4e00\u884c\u8f93\u5165\u5e76\u83b7\u53d6\u6574\u6570\n        System.out.printf("Hi, %s, you are %d\\n", name, age); \/\/ \u683c\u5f0f\u5316\u8f93\u51fa\n    }\n}<\/code><\/pre>\n
\u4f8b\u4e2d\u4f7f\u7528\u4e86nextLine()<\/code>\u51fd\u6570\u8bfb\u53d6\u4e00\u884c\u5b57\u7b26\u4e32\u548cnextInt()<\/code>\u51fd\u6570\u8bfb\u53d6\u4e00\u4e2a\u6574\u6570\u3002<\/p>\n
sort\u51fd\u6570\u4f7f\u7528 Comparable\u63a5\u53e3\u548cComparator\u63a5\u53e3<\/h5>\n
Java\u4e2d\u6709\u4e24\u4e2a\u6392\u5e8f\u65b9\u6cd5\uff0cjava.util.Arrays\u4e2d\u7684\u9759\u6001\u65b9\u6cd5sort()\u548cjava.util.Collections\u4e2d\u7684\u9759\u6001\u65b9\u6cd5sort()\u3002\u524d\u8005\u4e3b\u8981\u5bf9\u57fa\u672c\u7c7b\u578b\u548c\u5f15\u7528\u7c7b\u578b\u7684\u6570\u7ec4\u8fdb\u884c\u6392\u5e8f\uff0c\u540e\u8005\u5219\u662f\u5bf9\u4e00\u4e9b\u96c6\u5408\u6846\u67b6\u8fdb\u884c\u6392\u5e8f(\u94fe\u8868\uff0c\u6811\uff0c\u54c8\u5e0c\u8868ArrayList\uff0cHashSet\uff0cHashMap\u7b49)\u3002\u9664\u6b64\u533a\u522b\u4e4b\u5916\uff0c\u5176\u4f59\u7528\u6cd5\u5b8c\u5168\u76f8\u540c\u3002<\/p>\n
sort(byte[] a);            \/\/\u9ed8\u8ba4\u5347\u5e8f\u6392\u5217\nsort(byte[] a, int beginIndex, int endIndex);   \/\/ \u5bf9\u4e0b\u6807\u533a\u95f4[begin,end]\u5185\u7684\u5143\u7d20\u6392\u5e8f\nsort(T[], java.util.Comparator<? super T> c);   \/\/\u6839\u636e\u6307\u5b9a\u6bd4\u8f83\u5668\u4ea7\u751f\u7684\u987a\u5e8f\u5bf9\u6307\u5b9a\u5bf9\u8c61\u6570\u7ec4\u8fdb\u884c\u6392\u5e8f\nsort(T[], int beginIndex, int endIndex, java.util.Comparator<> super T> c);\n<\/code><\/pre>\n
sort\u51fd\u6570\u652f\u6301\u81ea\u5b9a\u4e49\u6392\u5e8f\uff0c\u901a\u8fc7\u91cd\u5199\u6bd4\u8f83\u5668java.util.Comparator\u53ef\u4ee5\u5b9e\u73b0\u5bf9\u5f15\u7528\u5bf9\u8c61\u6570\u7ec4\u6781\u6027\u6392\u5e8f\u3002\u5f53\u4e0d\u91cd\u65b0\u5b9a\u4e49\u6bd4\u8f83\u5668\u65f6\uff0csort\u51fd\u6570\u9ed8\u8ba4\u5347\u5e8f\u6392\u5217\uff1b\u5b9a\u4e49\u6bd4\u8f83\u5668\u65f6\uff0c\u53ea\u80fd\u5bf9\u5f15\u7528\u7c7b\u578b\u6570\u636e\u8fdb\u884c\u6392\u5217\uff0c\u57fa\u672c\u7c7b\u578b\u9700\u8981\u88c5\u7bb1\u540e\u624d\u80fd\u5b9a\u4e49\u4f7f\u7528\u6bd4\u8f83\u5668\u3002
\n\u4e00\u822c\u5728java.util.Comparator\u65b9\u6cd5\u4e2d\u5b9a\u4e49\u4e09\u79cd\u8fd4\u56de\u503c\uff081\uff0c -1\uff0c 0\uff09\u6765\u8fdb\u884c\u6392\u5e8f\u6807\u51c6\u7684\u786e\u8ba4\u3002
\n\u5f53\u786e\u8ba4\u8be5\u6392\u5e8f\u5173\u7cfb\u65f6\uff0c\u8fd4\u56de-1\uff1b\u786e\u8ba4\u8be5\u6392\u5e8f\u5173\u7cfb\u7684\u53cd\u5173\u7cfb\u65f6\uff0c\u8fd4\u56de1\uff1b\u5426\u5219\u8fd4\u56de0\u3002<\/p>\n
\/\/ \u5b9e\u73b0\u5bf9nums\u4e2d\u7684\u5143\u7d20\u8fdb\u884c\u5347\u5e8f\u6392\u5217\nInteger[] nums = new Integer[100];\njava.util.Collections.sort(nums, java.util.Comparator<Integer>(){\n    public int compare(Integar a, Integer b) {\n        if (a>b) return -1;\n        if (a<b) return 1;\n        return 0;\n    }\n});<\/code><\/pre>\n
\u5728\u5bf9\u8c61\u6570\u7ec4\u4e2d\u4e5f\u53ef\u4ee5\u901a\u8fc7\u5b9e\u73b0\u63a5\u53e3\u6765\u6dfb\u52a0\u6392\u5e8f\u529f\u80fd\u3002
\n\u8ba9\u5bf9\u8c61\u7ee7\u627fComparable\u63a5\u53e3\u7684\u65b9\u5f0f\uff0c\u79f0\u4e3a\u5185\u90e8\u6bd4\u8f83\u5668\u3002\u8be5\u5bf9\u8c61\u5b9e\u73b0\u63a5\u53e3Comparable\u63a5\u53e3\uff0c\u91cd\u5199compareTo\u65b9\u6cd5\u3002<\/p>\n
class student implements java.lang.Comparable{\n    int age;\n    int sex;\n    student(int age, int sex) {\n        super();\n        this.age = age;\n        this.sex = sex;\n    }\n    public int compareTo(Object o){\n        if (o instanceof student) {\n            student s = (student)o;\n            if (this.age > s.age) {\n                return 1;\n            }else if (this.age < s.age) {\n                return -1;\n            }else {\n                return 0;\n            }\n        }\n        return 0;\n    }\n};\n\/\/ usage\njava.util.Arrays.sort(stu);<\/code><\/pre>\n
\u4f7f\u7528Comparator\u63a5\u53e3\u65f6\uff0c\u79f0\u4e3a\u5916\u90e8\u6bd4\u8f83\u5668\u3002\u56e0\u4e3a\u91cd\u5199\u5176compare\u65b9\u6cd5\u9700\u8981\u4f20\u5165\u4e24\u4e2a\u53c2\u6570\u3002<\/p>\n
class comparable implements java.util.Comparator{\n    public int compare(Object o1, Object o2) {\n        if (o1 instanceof student) {\n            student s1 = (student) o1;\n            student s2 = (student) o2;\n            return s2.age - s1.age;\n        }\n        return 0;\n    }\n};\n\n\/\/usage\njava.util.Arrays.sort(stu, new comparable());<\/code><\/pre>\n
\u4e0b\u56fe\u662f\u4e24\u79cd\u63a5\u53e3\u7684\u5bf9\u6bd4\uff0c\uff0c\uff0c\u7f51\u4e0a\u62ff\u7684\u56fe\u5355\u8bcd\u6253\u9519\u4e86(Comparable  Comparator)
\n\"\"<\/p>\n
\u9762\u5411\u5bf9\u8c61 \u7ee7\u627f<\/h5>\n
Java\u4e2d\u6240\u6709\u7c7b\u90fd\u7ee7\u627f\u81eaObject<\/code>\u7c7b\uff0c\u4e14\u53ea\u6709\u8be5\u7c7b\u6ca1\u6709\u7236\u7c7b\u3002\u7ee7\u627f\u5173\u952e\u5b57\u4e3aextends<\/code>\uff0c\u7f3a\u7701\u8be5\u5173\u952e\u5b57\u65f6\u7f16\u8bd1\u5668\u4f1a\u81ea\u52a8\u52a0\u4e0aextends Object<\/code>\u3002\u5b50\u7c7b\u79f0\u4e3a\u5b50\u7c7b\uff0c\u6269\u5c55\u7c7b\uff1b\u7236\u7c7b\u79f0\u4e3a\u8d85\u7c7b\uff0c\u7236\u7c7b\uff0c\u57fa\u7c7b\u3002\u5728Java\u4e2d\u4e00\u4e2a\u7c7b\u53ea\u80fd\u76f4\u63a5\u7ee7\u627f\u4e00\u4e2a\u7c7b\uff0c\u4e5f\u5c31\u662f\u8bf4extends<\/code>\u5173\u952e\u5b57\u540e\u9762\u53ea\u80fd\u6709\u4e00\u4e2a\u7c7b\u540d\u3002
\n\u5b50\u7c7b\u81ea\u52a8\u7ee7\u627f\u7236\u7c7b\u7684\u6240\u6709\u5b57\u6bb5\uff0c\u4e25\u7981\u5b9a\u4e49\u4e0e\u7236\u7c7b\u91cd\u540d\u7684\u5b57\u6bb5\u3002
\n\u5b50\u7c7b\u65e0\u6cd5\u8bbf\u95ee\u7236\u7c7b\u7684private<\/code>\u5b57\u6bb5\u4e0e\u65b9\u6cd5\uff0c\u8fd9\u4f7f\u5f97\u7ee7\u627f\u7684\u4f5c\u7528\u88ab\u524a\u5f31\u4e86\uff0c\u4f46\u662f\u53ef\u4ee5\u8bbf\u95eeprotected<\/code>\u4fee\u9970\u7684\u5b57\u6bb5\u4e0e\u65b9\u6cd5\u3002protected<\/code>\u5173\u952e\u5b57\u53ef\u4ee5\u628a\u5b57\u6bb5\u548c\u65b9\u6cd5\u7684\u8bbf\u95ee\u6743\u9650\u63a7\u5236\u5728\u7ee7\u627f\u6811\u5185\u90e8\u3002
\nsuper<\/strong>super<\/code>\u5173\u952e\u5b57\u8868\u793a\u7236\u7c7b\uff08\u8d85\u7c7b\uff09\uff0c\u5b50\u7c7b\u5f15\u7528\u7236\u7c7b\u7684\u5b57\u6bb5\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528super.filedName<\/code>\u6765\u8bbf\u95ee\u3002\u5728Java\u4e2d\uff0c\u4efb\u4f55class<\/code>\u7684\u6784\u9020\u65b9\u6cd5\u7b2c\u4e00\u4e2a\u8bed\u53e5\u90fd\u5fc5\u987b\u662fsuper()<\/code>\uff0c\u5373\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u6ca1\u6709\u8be5\u8bed\u53e5\u65f6\u7f16\u8bd1\u5668\u4f1a\u81ea\u52a8\u6dfb\u52a0\u3002\u82e5\u7236\u7c7b\u6ca1\u6709\u9ed8\u8ba4\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u5373\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\u5fc5\u987b\u8981\u624b\u52a8\u4f20\u53c2\uff0c\u90a3\u4e48\u5c31\u5fc5\u987b\u5728\u5b50\u7c7b\u4e2d\u663e\u793a\u8c03\u7528super()<\/code>\u5e76\u7ed9\u51fa\u53c2\u6570\u4ee5\u4fbf\u8ba9\u7f16\u8bd1\u5668\u5b9a\u4f4d\u5230\u7236\u7c7b\u7684\u4e00\u4e2a\u5408\u9002\u7684\u6784\u9020\u65b9\u6cd5\u3002\u8fd8\u6709\uff0c\u5b50\u7c7b\u4e0d\u4f1a\u7ee7\u627f\u7236\u7c7b\u7684\u4efb\u4f55\u6784\u9020\u65b9\u6cd5\uff0c\u5b50\u7c7b\u7684\u9ed8\u8ba4\u6784\u9020\u65b9\u6cd5\u662f\u7f16\u8bd1\u5668\u9ed8\u8ba4\u751f\u6210\u7684\uff0c\u4e0d\u662f\u7ee7\u627f\u7684\u3002
\nsuper<\/code>\u5173\u952e\u5b57\u4e5f\u53ef\u4ee5\u8c03\u7528\u7236\u7c7b\u7684\u65b9\u6cd5\u3002
\n\u963b\u6b62\u7ee7\u627f<\/strong>Java\u4e2dfinal<\/code>\u4fee\u9970\u7684\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\uff0c\u5373\u4e0d\u4f1a\u6709\u4efb\u4f55\u5b50\u7c7b\uff0cfinal<\/code>\u5f71\u54cd\u7ee7\u627f\uff0c\u4f46\u4e0d\u6d89\u53ca\u7ee7\u627f\u3002final<\/code>\u4fee\u9970\u7684\u65b9\u6cd5\u4e0d\u5141\u8bb8\u88ab\u5b50\u7c7b\u8986\u5199\u3002
\n\u4eceJava15\u5f00\u59cb\uff0c\u5141\u8bb8\u4f7f\u7528sealed<\/code>\u4fee\u9970class\uff0c\u5e76\u901a\u8fc7permits<\/code>\u660e\u786e\u5199\u51fa\u80fd\u591f\u7ee7\u627f\u8be5\u7c7b\u7684\u5b50\u7c7b\u3002
\n\u5411\u4e0a\u8f6c\u578b\u4e0e\u5411\u4e0b\u8f6c\u578b<\/strong>\u5411\u4e0a\u8f6c\u578b\u5373\u4e00\u4e2a\u5f15\u7528\u7c7b\u578b\u4e3a\u7236\u7c7b\u7684\u53d8\u91cf\u53ef\u4ee5\u6307\u5411\u5b50\u7c7b\u7684\u5b9e\u4f8b\uff0c\u56e0\u4e3a\u5b50\u7c7b\u62e5\u6709\u7236\u7c7b\u7684\u5168\u90e8\u5c5e\u6027\u548c\u529f\u80fd\uff0c\u90a3\u4e48\u5c31\u6ca1\u6709\u95ee\u9898\u3002\u76f8\u53cd\uff0c\u5411\u4e0b\u8f6c\u578b\u5373\u4e00\u4e2a\u5f15\u7528\u7c7b\u578b\u4e3a\u5b50\u7c7b\u7684\u53d8\u91cf\u6307\u5411\u7236\u7c7b\u7684\u5b9e\u4f8b\uff0c\u8fd9\u662f\u4e0d\u5141\u8bb8\u7684\uff0cJava\u865a\u62df\u673a\u4f1a\u62a5ClassCastExpection<\/code>\u9519\u8bef\u3002\u56e0\u4e3a\u7236\u7c7b\u65e0\u6cd5\u63d0\u4f9b\u5b50\u7c7b\u6240\u9700\u7684\u5168\u90e8\u529f\u80fd\uff0c\u591a\u7684\u529f\u80fd\u65e0\u6cd5\u51ed\u7a7a\u53d8\u51fa\u6765\u3002
\n\u4e3a\u907f\u514d\u8fd9\u79cd\u9519\u8bef\uff0c\u8f6c\u578b\u4e4b\u524d\u53ef\u4ee5\u4f7f\u7528instanceof<\/code>\u64cd\u4f5c\u7b26\u5224\u65ad\u4e00\u4e0b\u3002
\ninstance\u5b9e\u9645\u4e0a\u5224\u65ad\u4e00\u4e2a\u53d8\u91cf\u6240\u6307\u7684\u5b9e\u4f8b\u662f\u5426\u4e3a\u6307\u5b9a\u7c7b\u578b\uff0c\u6216\u8005\u8fd9\u4e2a\u7c7b\u578b\u7684\u5b50\u7c7b\u3002
\nJava14\u4e4b\u540e\uff0c\u53ef\u4ee5\u5728\u5224\u65ad\u7c7b\u578b\u4e00\u81f4\u65f6\u76f4\u63a5\u521b\u5efa\u65b0\u7684\u5f15\u7528\u3002<\/p>\n
public class Main{\n    public static void main (String[] args) {\n        Object obj = "Hello world!";\n        if (obj instanceof String s) {\n            ;    \/\/ \u5224\u65ad\u4e3atrue\u65f6 s\u5df2\u7ecf\u521b\u5efa\uff0c\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u3002s\u548cobj\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61\n        }\n    }\n}<\/code><\/pre>\n
\u591a\u6001<\/h5>\n
\u591a\u6001\u662f\u6307\uff0c\u9488\u5bf9\u67d0\u4e2a\u7c7b\u578b\u7684\u65b9\u6cd5\u8c03\u7528\uff0c\u5176\u771f\u6b63\u6267\u884c\u7684\u65b9\u6cd5\u53d6\u51b3\u4e8e\u8fd0\u884c\u65f6\u671f\u5b9e\u9645\u7c7b\u578b\u7684\u65b9\u6cd5\u3002
\nJava\u4e2d\u91cd\u8f7d\u51fd\u6570\u5141\u8bb8\u65b9\u6cd5\u540d\u548c\u53c2\u6570\u90fd\u76f8\u540c\uff0c\u4f46\u8fd4\u56de\u7c7b\u578b\u4e0d\u540c\u7684\u60c5\u51b5\u3002\u5728\u7ee7\u627f\u5173\u7cfb\u4e2d\uff0c\u5b50\u7c7b\u5982\u679c\u5b9a\u4e49\u4e0e\u7236\u7c7b\u65b9\u6cd5\u7b7e\u540d\u5b8c\u5168\u76f8\u540c\u7684\u65b9\u6cd5\uff0c\u88ab\u79f0\u4e3a\u8986\u5199(override).
\n\u591a\u6001\u7684\u7279\u6027\u5c31\u662f\uff0c\u8fd0\u884c\u671f\u624d\u80fd\u52a8\u6001\u51b3\u5b9a\u8c03\u7528\u7684\u5b50\u7c7b\u65b9\u6cd5\u3002\u56e0\u4e3a\u53ea\u6709\u8fd0\u884c\u65f6\u624d\u80fd\u77e5\u9053\u53d8\u91cf\u6240\u6307\u7684\u5b9e\u9645\u7c7b\u578b\u3002
\n\u6bd4\u5982\u5bf9\u4e8e\u4e00\u4e2a\u7ee7\u627f\u6811\u4e0a\u7684\u51e0\u4e2a\u7c7b\uff0c\u6211\u4eec\u5e0c\u671b\u628a\u5b83\u4eec\u653e\u5728\u4e00\u4e2a\u6570\u7ec4\u91cc\u8fdb\u884c\u64cd\u4f5c\uff0c\u5c31\u53ea\u9700\u8981\u5b9a\u4e49\u53d8\u91cf\u7c7b\u578b\u4e3a\u5b83\u4eec\u7684\u516c\u5171\u7236\u7c7b\u7c7b\u578b\uff0c\u800c\u5b9e\u9645\u4f7f\u7528\u65f6\uff0c\u6211\u4eec\u5e76\u4e0d\u77e5\u9053\u6bcf\u4e2a\u53d8\u91cf\u6240\u6307\u7684\u5b9e\u9645\u7c7b\u578b\uff0c\u4f46\u662f\u8c03\u7528\u76f8\u540c\u540d\u5b57\u7684\u65b9\u6cd5\u65f6\uff0c\u5c31\u53ef\u4ee5\u52a8\u6001\u6839\u636e\u6bcf\u4e2a\u5b9e\u9645\u7c7b\u578b\u81ea\u8eab\u6765\u5b9e\u9645\u8c03\u7528\u54ea\u4e2a\u51fd\u6570\u3002\u53ef\u89c1\uff0c\u591a\u6001\u662f\u4e00\u4e2a\u975e\u5e38\u5f3a\u5927\u7684\u529f\u80fd\uff0c\u5c31\u662f\u5141\u8bb8\u6dfb\u52a0\u66f4\u591a\u7c7b\u578b\u7684\u5b50\u7c7b\u5b9e\u73b0\u529f\u80fd\u6269\u5c55\uff0c\u5374\u4e0d\u9700\u8981\u4fee\u6539\u7236\u7c7b\u7684\u4ee3\u7801\u3002<\/p>\n
\u62bd\u8c61\u7c7b \u9762\u5411\u62bd\u8c61\u7f16\u7a0b<\/h5>\n
\u7531\u4e8e\u591a\u6001\u7684\u5b9a\u4e49\uff0c\u6bcf\u4e2a\u5b50\u7c7b\u90fd\u53ef\u4ee5\u5b9a\u4e49\u4e0e\u7236\u7c7b\u540c\u540d\u7684\u65b9\u6cd5\uff0c\u4f46\u662f\u7236\u7c7b\u7684\u65b9\u6cd5\u5b9e\u73b0\u6ca1\u6709\u4efb\u4f55\u5b9e\u9645\u610f\u4e49\uff0c\u53c8\u4e0d\u80fd\u53bb\u6389\uff0c\u5426\u5219\u5c31\u4e0d\u80fd\u7528\u7236\u7c7b\u53d8\u91cf\u7c7b\u578b\u6765\u6267\u884c\u5b50\u7c7b\u65b9\u6cd5\u4e86\uff0c\u5c31\u5931\u53bb\u591a\u6001\u6027\u4e86\uff0c\u8fd9\u5c31\u5f88\u70e6\uff0c\u56e0\u4e3a\u6211\u4eec\u53ea\u9700\u8981\u7236\u7c7b\u7684\u8fd9\u4e2a\u65b9\u6cd5\u7684\u58f0\u660e\uff0c\u6240\u4ee5\u5c31\u6709\u4e86\u62bd\u8c61<\/strong>\u7684\u6982\u5ff5\u3002\u53ef\u4ee5\u7528abstract<\/code>\u5173\u952e\u5b57\u4fee\u9970\u65b9\u6cd5\u6765\u4f7f\u5176\u6210\u4e3a\u4e00\u4e2a\u62bd\u8c61\u65b9\u6cd5\uff0c\u8fd9\u6837\u5c31\u4e0d\u9700\u8981\u5177\u4f53\u5b9e\u73b0\u8fd9\u4e2a\u65b9\u6cd5\uff0c\u800c\u4ec5\u4ec5\u662f\u4e00\u4e2a\u58f0\u660e\u3002\u62bd\u8c61\u65b9\u6cd5\u5fc5\u987b\u653e\u5728\u62bd\u8c61\u7c7b\u4e2d\uff0c\u62bd\u8c61\u7c7b\u65e0\u6cd5\u5b9e\u4f8b\u5316\u3002
\n\u62bd\u8c61\u7c7b\u91cc\u9762\u53ef\u4ee5\u5b9a\u4e49\u62bd\u8c61\u65b9\u6cd5\uff0c\u4e5f\u53ef\u4ee5\u5b9a\u4e49\u975e\u62bd\u8c61\u65b9\u6cd5\uff0c\u751a\u81f3\u5168\u90e8\u90fd\u5b9a\u4e49\u6210\u975e\u62bd\u8c61\u65b9\u6cd5\u90fd\u53ef\u4ee5\u3002<\/p>\n
public abstract class Test {\n    public static void main(String[] args) {\n        System.out.println("abstract");\n    }\n}<\/code><\/pre>\n
\u5f53\u4e00\u4e2a\u7c7b\u88ababstract<\/code>\u5173\u952e\u5b57\u5b9a\u4e49\u4e3a\u62bd\u8c61\u7c7b\u65f6\uff0c\u8fd9\u4e2a\u7c7b\u5c31\u53ea\u80fd\u88ab\u7528\u6765\u7ee7\u627f\uff0c\u62bd\u8c61\u7c7b\u5f3a\u8feb\u5176\u5b50\u7c7b\u5b9e\u73b0\u5176\u58f0\u660e\u7684\u6240\u6709\u65b9\u6cd5\uff0c\u5426\u5219\u7f16\u8bd1\u62a5\u9519\u3002\u62bd\u8c61\u65b9\u6cd5\u5b9e\u9645\u4e0a\u76f8\u5f53\u4e8e\u5b9a\u4e49\u4e86\u201c\u89c4\u8303\u201d<\/strong>\u3002\u5f53\u62bd\u8c61\u7c7b\u7684\u5b50\u7c7b\u5e76\u6ca1\u6709\u5b9e\u73b0\u5176\u65b9\u6cd5\u65f6\uff0c\u5b50\u7c7b\u4ecd\u7136\u662f\u4e00\u4e2a\u62bd\u8c61\u7c7b\uff0c\u5373\u62bd\u8c61\u7c7b\u53ef\u4ee5\u7ee7\u627f\u62bd\u8c61\u7c7b\u3002<\/p>\n
abstract class Person {\n    public abstract void run();\n}\nclass Student extends Person {\n    public void run() {\n        System.out.println("Student.run");\n    }\n}\nclass Teacher extends Person {\n    public void run() {\n        System.out.println("Teacher.run");\n    }\n}\nPerson p1 = new Student();\nPerson p2 = new Teacher();<\/code><\/pre>\n
\u53ef\u4ee5\u7528\u62bd\u8c61\u7c7b\u7c7b\u578b\u53bb\u5f15\u7528\u5177\u4f53\u7684\u5b50\u7c7b\u578b\u7684\u5b9e\u4f8b\uff0c\u6211\u4eec\u5bf9\u5176\u65b9\u6cd5\u8fdb\u884c\u8c03\u7528\uff0c\u5e76\u4e0d\u5173\u5fc3\u8be5\u53d8\u91cf\u5177\u4f53\u7684\u5b50\u7c7b\u578b\u3002\u5c3d\u91cf\u5f15\u7528\u9ad8\u5c42\u7c7b\u578b\uff0c\u907f\u514d\u5f15\u7528\u4e86\u5b9e\u9645\u5b50\u7c7b\u578b\u7684\u65b9\u5f0f\uff0c\u79f0\u4e4b\u4e3a\u9762\u5411\u62bd\u8c61\u7f16\u7a0b\u3002
\n\u9762\u5411\u62bd\u8c61\u7f16\u7a0b\u7684\u672c\u8d28\uff1a<\/p>\n
\n
\u4e0a\u5c42\u4ee3\u7801\u53ea\u5b9a\u4e49\u89c4\u8303
\n\u4e0d\u9700\u8981\u5b50\u7c7b\u5c31\u53ef\u4ee5\u5b9e\u73b0\u4e1a\u52a1\u903b\u8f91
\n\u5177\u4f53\u7684\u4e1a\u52a1\u903b\u8f91\u7531\u4e0d\u540c\u7684\u5b50\u7c7b\u5b9e\u73b0\uff0c\u8c03\u7528\u8005\u5e76\u4e0d\u5173\u5fc3\u3002<\/p>\n<\/blockquote>\n
\u5bf9\u4e8e\u62bd\u8c61\u7c7b\u7684\u975e\u62bd\u8c61\u65b9\u6cd5\uff0c\u82e5\u8be5\u7c7b\u7684\u5b50\u7c7b\u6ca1\u6709\u8986\u5199\u6b64\u975e\u62bd\u8c61\u65b9\u6cd5\uff0c\u90a3\u4e48\u5b50\u7c7b\u5c31\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\u975e\u62bd\u8c61\u65b9\u6cd5\uff0c\u4e0d\u7528\u518d\u53bb\u5b9e\u73b0\u3002\u5c31\u53ea\u662f\u7b80\u5355\u7684\u7ee7\u627f\u8be5\u65b9\u6cd5\u3002<\/p>\n
\u62bd\u8c61\u7c7b\u662f\u4e8b\u7269\u7684\u62bd\u8c61\uff0c\u63a5\u53e3\u662f\u884c\u4e3a\u7684\u62bd\u8c61<\/p>\n
\u63a5\u53e3 interface<\/h5>\n
\u5982\u679c\u4e00\u4e2a\u62bd\u8c61\u7c7b\u6ca1\u6709\u5b57\u6bb5\uff0c\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u62bd\u8c61\u65b9\u6cd5\uff0c\u90a3\u4e48\u53ef\u4ee5\u628a\u8be5\u62bd\u8c61\u7c7b\u5b9a\u4e49\u4e3a\u63a5\u53e3\uff0c\u7528interface<\/code>\u6765\u58f0\u660e\u3002\u63a5\u53e3\u662f\u6bd4\u62bd\u8c61\u7c7b\u8fd8\u8981\u62bd\u8c61\u7684\u7eaf\u62bd\u8c61\u63a5\u53e3\uff0c\u63a5\u53e3\u7684\u6240\u6709\u65b9\u6cd5\u90fd\u662f\u9ed8\u8ba4\u88abpublic abstract<\/code>\u4fee\u9970\u7684\uff0c\u5199\u4e0d\u5199\u90fd\u4e00\u6837\u3002\u5f53\u4e00\u4e2a\u7c7b\u5b9e\u73b0\u5177\u4f53\u7684\u63a5\u53e3\u65f6\u9700\u8981\u7528implements<\/code>\u5173\u952e\u5b57\u3002<\/p>\n
interface Person {\n    void run();\n    String getName();\n}\nclass Student implements Person {\n    String name;\n    @override\n    public void run() {\n        System.out.println(this.name + " run");\n    }\n    @override\n    public String getName() {\n        return this.name;\n    }\n}<\/code><\/pre>\n
\u5728Java\u4e2d\uff0c\u4e00\u4e2a\u7c7b\u53ea\u80fd\u7ee7\u627f\u81ea\u4e00\u4e2a\u7c7b\uff0c\u4f46\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\u3002\u8fd9\u5c31\u53ef\u4ee5\u53d8\u76f8\u7684\u4f7fJava\u5177\u6709\u591a\u7ee7\u627f\u7684\u7279\u6027\uff0c\u4f7f\u7528\u8303\u56f4\u4e3a\u7c7b\u7ee7\u627f\u63a5\u53e3\u7684\u60c5\u51b5\u3002
\nJava\u7684\u63a5\u53e3\u7279\u6307interface<\/code>\u7684\u5b9a\u4e49\uff0c\u8868\u793a\u4e00\u4e2a\u63a5\u53e3\u7c7b\u578b\u548c\u4e00\u7ec4\u65b9\u6cd5\u7b7e\u540d\uff0c\u800c\u7f16\u7a0b\u63a5\u53e3\u6cdb\u6307\u63a5\u53e3\u89c4\u8303\uff0c\u5982\u65b9\u6cd5\u7b7e\u540d\uff0c\u6570\u636e\u683c\u5f0f\uff0c\u7f51\u7edc\u534f\u8bae\u7b49\u3002
\n\"\"<\/p>\n
\u5408\u7406\u8bbe\u8ba1interface<\/code>\u548cabstract class<\/code>\u7684\u7ee7\u627f\u5173\u7cfb\uff0c\u53ef\u4ee5\u5145\u5206\u590d\u7528\u4ee3\u7801\u3002\u5728\u4f7f\u7528\u7684\u65f6\u5019\uff0c\u5b9e\u4f8b\u5316\u7684\u5bf9\u8c61\u6c38\u8fdc\u53ea\u80fd\u662f\u67d0\u4e2a\u5177\u4f53\u7684\u5b50\u7c7b\uff0c\u4f46\u603b\u662f\u901a\u8fc7\u63a5\u53e3\u53bb\u5f15\u7528\u5b83\uff0c\u56e0\u4e3a\u63a5\u53e3\u6bd4\u62bd\u8c61\u7c7b\u66f4\u62bd\u8c61\uff1a<\/p>\n
List list = new ArrayList();    \/\/ \u7528List\u63a5\u53e3\u5f15\u7528\u5177\u4f53\u5b50\u7c7b\u7684\u5b9e\u4f8b\nCollection col = list;         \/\/\u5411\u4e0a\u8f6c\u578b\nIterable it = col;            \/\/\u8fd8\u53ef\u4ee5\u7ee7\u7eed\u5411\u4e0a\u8f6c\u578b<\/code><\/pre>\n
default<\/code><\/strong>\u5173\u952e\u5b57\u3002\u65e2\u7136\u8981\u4e00\u4e2a\u7c7b\u5b9e\u73b0\u4e00\u4e2a\u63a5\u53e3\u5fc5\u987b\u8981\u5b9e\u73b0\u5176\u5168\u90e8\u65b9\u6cd5\uff0c\u90a3\u4e48\u6211\u4eec\u53ea\u8981\u7a0d\u7a0d\u4fee\u6539\u4e00\u4e0b\u4e00\u4e2a\u63a5\u53e3\uff0c\u6bd4\u5982\u65b0\u589e\u52a0\u4e00\u4e2a\u65b9\u6cd5\u58f0\u660e\uff0c\u662f\u4e0d\u662f\u5c31\u8fd8\u8981\u5728\u5176\u6240\u6709\u5b50\u7c7b\u4e2d\u4e00\u4e2a\u4e00\u4e2a\u53bb\u589e\u52a0\u5462\uff0c\u8fd9\u4e5f\u592a\u9ebb\u70e6\u4e86\uff0c\u6211\u4eec\u53ef\u4ee5\u628a\u8be5\u65b9\u6cd5\u7528\u5173\u952e\u5b57default<\/code>\u4fee\u9970\u4e00\u4e0b\uff0c\u8fd9\u6837\u5b50\u7c7b\u5c31\u4e0d\u9700\u8981\u5f3a\u5236\u5b9e\u73b0\u7ed9\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5b9e\u73b0\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u5b9e\u73b0\uff0c\u6211\u4eec\u53ea\u9700\u8981\u6839\u636e\u60c5\u51b5\u5728\u9700\u8981\u7684\u5b50\u7c7b\u4e2d\u5b9e\u73b0\u8be5\u65b9\u6cd5\u5373\u53ef\u3002
\n\u56e0\u4e3ainterface\u4e2d\u6ca1\u6709\u5b57\u6bb5\uff0cdefault<\/code>\u65b9\u6cd5\u65e0\u6cd5\u8bbf\u95ee\u5b57\u6bb5\uff0c\u800c\u62bd\u8c61\u7c7b\u7684\u666e\u901a\u65b9\u6cd5\u53ef\u4ee5\u8bbf\u95ee\u5b9e\u4f8b\u5b57\u6bb5\u3002<\/p>\n
Java\u6cdb\u578b<\/h5>\n
Java\u6cdb\u578b\u76f8\u5f53\u4e8eC++\u91cc\u7684\u6a21\u677f\u3002\u6cdb\u578b\u63d0\u4f9b\u4e86\u7f16\u8bd1\u65f6\u7c7b\u578b\u5b89\u5168\u68c0\u6d4b\u673a\u5236\uff0c\u8be5\u673a\u5236\u5141\u8bb8\u7a0b\u5e8f\u5458\u5728\u7f16\u8bd1\u65f6\u68c0\u6d4b\u5230\u975e\u6cd5\u7684\u7c7b\u578b\u3002
\n\u6cdb\u578b\u7684\u672c\u8d28\u662f\u53c2\u6570\u5316\u7c7b\u578b\uff0c\u4e5f\u5c31\u662f\u8bf4\u6240\u64cd\u4f5c\u7684\u6570\u636e\u7c7b\u578b\u88ab\u6307\u5b9a\u4e3a\u4e00\u4e2a\u53c2\u6570\u3002\u6cdb\u578b\u5305\u62ec\u6cdb\u578b\u65b9\u6cd5\u548c\u6cdb\u578b\u7c7b\u3002
\n\u4e00\u4e2a\u6cdb\u578b\u65b9\u6cd5\u5728\u8c03\u7528\u65f6\u53ef\u4ee5\u63a5\u6536\u4e0d\u540c\u7c7b\u578b\u7684\u53c2\u6570\u3002\u6839\u636e\u4f20\u9012\u7ed9\u6cdb\u578b\u65b9\u6cd5\u7684\u53c2\u6570\u7c7b\u578b\uff0c\u7f16\u8bd1\u5668\u9002\u5f53\u5730\u5904\u7406\u6bcf\u4e00\u4e2a\u65b9\u6cd5\u8c03\u7528\u3002\u5b9a\u4e49\u6cdb\u578b\u65b9\u6cd5\u7684\u89c4\u5219\uff1a<\/p>\n
\n
\u6240\u6709\u6cdb\u578b\u65b9\u6cd5\u58f0\u660e\u90fd\u6709\u4e00\u4e2a\u7c7b\u578b\u53c2\u6570\u58f0\u660e\u90e8\u5206\uff08\u7531\u5c16\u62ec\u53f7\u5206\u9694\uff09\uff0c\u8be5\u7c7b\u578b\u53c2\u6570\u58f0\u660e\u90e8\u5206\u5728\u65b9\u6cd5\u8fd4\u56de\u7c7b\u578b\u4e4b\u524d\uff08\u5728\u4e0b\u9762\u4f8b\u5b50\u4e2d\u7684 \uff09\u3002
\n\u6bcf\u4e00\u4e2a\u7c7b\u578b\u53c2\u6570\u58f0\u660e\u90e8\u5206\u5305\u542b\u4e00\u4e2a\u6216\u591a\u4e2a\u7c7b\u578b\u53c2\u6570\uff0c\u53c2\u6570\u95f4\u7528\u9017\u53f7\u9694\u5f00\u3002\u4e00\u4e2a\u6cdb\u578b\u53c2\u6570\uff0c\u4e5f\u88ab\u79f0\u4e3a\u4e00\u4e2a\u7c7b\u578b\u53d8\u91cf\uff0c\u662f\u7528\u4e8e\u6307\u5b9a\u4e00\u4e2a\u6cdb\u578b\u7c7b\u578b\u540d\u79f0\u7684\u6807\u8bc6\u7b26\u3002
\n\u7c7b\u578b\u53c2\u6570\u80fd\u88ab\u7528\u6765\u58f0\u660e\u8fd4\u56de\u503c\u7c7b\u578b\uff0c\u5e76\u4e14\u80fd\u4f5c\u4e3a\u6cdb\u578b\u65b9\u6cd5\u5f97\u5230\u7684\u5b9e\u9645\u53c2\u6570\u7c7b\u578b\u7684\u5360\u4f4d\u7b26\u3002
\n\u6cdb\u578b\u65b9\u6cd5\u4f53\u7684\u58f0\u660e\u548c\u5176\u4ed6\u65b9\u6cd5\u4e00\u6837\u3002\u6ce8\u610f\u7c7b\u578b\u53c2\u6570\u53ea\u80fd\u4ee3\u8868\u5f15\u7528\u578b\u7c7b\u578b\uff0c\u4e0d\u80fd\u662f\u539f\u59cb\u7c7b\u578b\uff08\u50cf int\u3001double\u3001char \u7b49\uff09\u3002<\/p>\n<\/blockquote>\n
java\u4e2d\u6cdb\u578b\u6807\u8bb0\u7b26\uff1a<\/p>\n
\n
E<\/strong> - Element (\u5728\u96c6\u5408\u4e2d\u4f7f\u7528\uff0c\u56e0\u4e3a\u96c6\u5408\u4e2d\u5b58\u653e\u7684\u662f\u5143\u7d20)
\nT<\/strong> - Type\uff08Java \u7c7b\uff09
\nK<\/strong> - Key\uff08\u952e\uff09
\nV<\/strong> - Value\uff08\u503c\uff09
\nN<\/strong> - Number\uff08\u6570\u503c\u7c7b\u578b\uff09
\n?<\/strong> - \u8868\u793a\u4e0d\u786e\u5b9a\u7684 java \u7c7b\u578b<\/p>\n<\/blockquote>\n
public class GenericMethodTest {\n    public static < E > void printArray( E[] inputArray ) {\n        for ( E element : inputArray)\n            System.out.printf( "%s ", element );\n        System.out.println();\n    }\n    public static void main( String args[] )\n    {\n        \/\/ \u521b\u5efa\u4e0d\u540c\u7c7b\u578b\u6570\u7ec4\uff1a Integer, Double \u548c Character\n        Integer[] intArray = { 1, 2, 3, 4, 5 };\n        Double[] doubleArray = { 1.1, 2.2, 3.3, 4.4 };\n        Character[] charArray = { 'H', 'E', 'L', 'L', 'O' };\n\n        System.out.println( "\u6574\u578b\u6570\u7ec4\u5143\u7d20\u4e3a:" );\n        printArray( intArray  ); \/\/ \u4f20\u9012\u4e00\u4e2a\u6574\u578b\u6570\u7ec4\n\n        System.out.println( "\\n\u53cc\u7cbe\u5ea6\u578b\u6570\u7ec4\u5143\u7d20\u4e3a:" );\n        printArray( doubleArray ); \/\/ \u4f20\u9012\u4e00\u4e2a\u53cc\u7cbe\u5ea6\u578b\u6570\u7ec4\n\n        System.out.println( "\\n\u5b57\u7b26\u578b\u6570\u7ec4\u5143\u7d20\u4e3a:" );\n        printArray( charArray ); \/\/ \u4f20\u9012\u4e00\u4e2a\u5b57\u7b26\u578b\u6570\u7ec4\n    }\n}<\/code><\/pre>\n
\u6cdb\u578b\u7c7b\uff1a<\/p>\n
public class Box<T> {\n\n  private T t;\n\n  public void add(T t) {\n    this.t = t;\n  }\n\n  public T get() {\n    return t;\n  }\n\n  public static void main(String[] args) {\n    Box<Integer> integerBox = new Box<Integer>();\n    Box<String> stringBox = new Box<String>();\n\n    integerBox.add(new Integer(10));\n    stringBox.add(new String("\u83dc\u9e1f\u6559\u7a0b"));\n\n    System.out.printf("\u6574\u578b\u503c\u4e3a :%d\\n\\n", integerBox.get());\n    System.out.printf("\u5b57\u7b26\u4e32\u4e3a :%s\\n", stringBox.get());\n  }\n}<\/code><\/pre>\n
\u6cdb\u578b\u5f15\u7528<\/strong>
\n\u5728\u4f7f\u7528\u6cdb\u578b\u7c7b\u65f6\uff0c\u9700\u8981\u5148\u5b9a\u4e49\u4e00\u4e2a\u6cdb\u578b\u7c7b\u7684\u5f15\u7528\uff0c\u6307\u5b9a\u5177\u4f53\u7684\u7c7b\u578b\u3002<\/p>\n
Score<Integer> score;<\/code><\/pre>\n
\u4e5f\u53ef\u4ee5\u4e0d\u6307\u5b9a\u5177\u4f53\u7c7b\u578b\uff0c\u7528\u901a\u914d\u7b26?<\/code>\u4ee3\u66ff\uff0c\u7528\u6765\u8868\u793a\u53ef\u4ee5\u6307\u5b9a\u4efb\u610f\u7c7b\u578b\u3002<\/p>\n
Score<?> score;<\/code><\/pre>\n
\u6cdb\u578b\u7684\u754c\u9650<\/strong>
\n\u5728\u8fd9\u91cc\u9700\u8981\u5f15\u5165\u4e00\u4e2a\u91cd\u8981\u7684\u6982\u5ff5\uff1a\u6cdb\u578b\u7684\u754c\u9650\u3002\u5f53\u6211\u4eec\u6ca1\u6709\u6307\u5b9a\u5177\u4f53\u4f7f\u7528\u7684\u7c7b\u578b\u65f6\uff0c\u7f16\u8bd1\u5668\u5e76\u4e0d\u77e5\u9053\u5177\u4f53\u7684\u7c7b\u578b\uff0c\u90a3\u4e48\u7c7b\u578b\u5c31\u6709\u4e86\u4e00\u4e2a\u754c\u9650\uff0c\u6bd4\u5982\u4f7f\u7528\u901a\u914d\u7b26\u540e\uff0c\u7c7b\u578b\u7684\u4e0a\u9650\u5c31\u662fObject<\/code>\u7c7b\uff0c\u800c\u6b64\u65f6\u7f16\u8bd1\u5668\u5e76\u4e0d\u77e5\u9053\u5e94\u8be5\u628a\u8fd9\u4e2a\u7c7b\u58f0\u660e\u5177\u4f53\u5316\u4e3a\u54ea\u4e2a\u7c7b\u7684\u58f0\u660e\uff0c\u90a3\u4e48\u5c31\u4f1a\u81ea\u52a8\u628a\u751f\u6210\u7684\u5bf9\u8c61\u5b9a\u4e49\u4e3a\u4e0a\u9650\u7c7b\u578bObject<\/code>\u3002<\/p>\n
\u4e5f\u53ef\u4ee5\u6307\u5b9a\u6cdb\u578b\u7684\u754c\u9650\uff1aextends<\/code>\u5173\u952e\u5b57\u7528\u6765\u6307\u5b9a\u4e0a\u9650\uff0csuper<\/code>\u5173\u952e\u5b57\u7528\u6765\u6307\u5b9a\u4e0b\u9650\u3002<\/p>\n
public class<T extends Number> {    \/\/\u8bbe\u5b9a\u4e0a\u754c\uff0c\u5373\u7c7b\u578b\u5fc5\u987b\u662fNumber\u7684\u5b50\u7c7b\n\n}\n\nPublic class<T super Integer> {    \/\/\u8bbe\u5b9a\u4e0b\u754c\uff0c\u5373\u7c7b\u578b\u5fc5\u987b\u662fInteger\u7684\u7236\u7c7b\uff0c\u6b64\u65f6\u4e0a\u754c\u4ecd\u7136\u662fObject\n\n}<\/code><\/pre>\n
\u5728\u6cdb\u578b\u901a\u914d\u7b26\u91cc\u4e5f\u53ef\u4ee5\u4f7f\u7528\u6cdb\u578b\u7684\u754c\u9650\uff1a<\/p>\n
Score<? extends Number> score;   \/\/\u9650\u5b9a\u4e3aNumber\u7684\u5b50\u7c7b<\/code><\/pre>\n
\u6ce8\u610f\u6307\u5b9a\u4e0a\u754c\u4e4b\u540e\uff0c\u8be5\u6cdb\u578b\u5f15\u7528\u5c31\u81ea\u52a8\u58f0\u660e\u4e3a\u4e0a\u754c\u7c7b\u7684\u5f15\u7528Number<\/code>\u3002<\/p>\n
Score<? extends Number> score;   \/\/\u9650\u5b9a\u4e3aNumber\u7684\u7236\u7c7b<\/code><\/pre>\n
\u6307\u5b9a\u4e0b\u754c\u540e\uff0c\u4e0a\u754c\u6ca1\u6709\u53d8\u4ecd\u7136\u4e3aObject<\/code>\uff0c\u90a3\u4e48\u6700\u540e\u751f\u6210\u7684\u5f15\u7528\u4ecd\u7136\u662fObject<\/code>\u7c7b\u578b\u7684\u5f15\u7528\u3002<\/p>\n
\u679a\u4e3e\u7c7b<\/h5>\n
Java\u679a\u4e3e\u7c7b\u662f\u4e00\u4e2a\u7279\u6b8a\u7684\u7c7b\uff0c\u4e00\u822c\u8868\u793a\u4e00\u7ec4\u5e38\u91cf\uff0c\u4f7f\u7528enum<\/code>\u5173\u952e\u5b57\u6765\u5b9a\u4e49\uff0c\u5404\u4e2a\u5e38\u91cf\u4e4b\u95f4\u7528,<\/code>\u9694\u5f00\u3002<\/p>\n
public enum Color {\n    RED, GREEN, BLUE;\n    private Color() {\n        System.out.println("Constructor called for: " + this.toString());\n    }\n    public void ColorInfo() {\n        System.out.println("Universal Color");\n    }\n}\n<\/code><\/pre>\n
\u679a\u4e3e\u7c7b\u5185\u90e8\u7684\u6bcf\u4e00\u4e2a\u5e38\u91cf\u90fd\u662f\u4e00\u4e2a\u679a\u4e3e\u3002\u6bcf\u4e2a\u679a\u4e3e\u90fd\u662f\u901a\u8fc7 Class \u5728\u5185\u90e8\u5b9e\u73b0\u7684\uff0c\u4e14\u6240\u6709\u7684\u679a\u4e3e\u503c\u90fd\u662f public static final \u7684\u3002\u679a\u4e3e\u7c7b\u7684\u7528\u5904\u5c31\u662f\u4f7f\u5f00\u53d1\u8005\u4eec\u4ec5\u80fd\u4f7f\u7528\u5df2\u7ecf\u5b9a\u4e49\u597d\u7684\u72b6\u6001\u3002<\/p>\n
Color.valueOf("")   \/\/\u5c06\u540d\u79f0\u76f8\u540c\u7684\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u679a\u4e3e\nColor.values()   \/\/\u5feb\u901f\u83b7\u53d6\u6240\u6709\u7684\u679a\u4e3e<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
Java\u662f\u89e3\u91ca\u578b\u8bed\u8a00\u3002JVM\u4f1a\u5148\u628ajava\u6e90\u4ee3\u7801\u7f16\u8bd1\u6210\u5b57\u8282\u7801\uff0c\u82e5\u5728\u7f16\u8bd1\u8fc7\u7a0b\u4e2d\u65e0\u8bed\u6cd5\u9519\u8bef\uff0c\u6210\u529f\u751f\u6210\u5b57\u8282 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[75],"tags":[],"_links":{"self":[{"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/posts\/1020"}],"collection":[{"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/comments?post=1020"}],"version-history":[{"count":51,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/posts\/1020\/revisions"}],"predecessor-version":[{"id":1448,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/posts\/1020\/revisions\/1448"}],"wp:attachment":[{"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/media?parent=1020"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/categories?post=1020"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.zyhcoding.club\/index.php\/wp-json\/wp\/v2\/tags?post=1020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}