{"id":5499,"date":"2024-04-14T11:47:18","date_gmt":"2024-04-14T03:47:18","guid":{"rendered":"http:\/\/zyg.luchers.cn\/?p=5499"},"modified":"2024-04-14T11:47:18","modified_gmt":"2024-04-14T03:47:18","slug":"%e6%b3%9b%e5%9e%8b%e3%80%90%e6%b3%9b%e5%9e%8b%e4%bb%8b%e7%bb%8d%e3%80%81%e8%87%aa%e5%ae%9a%e4%b9%89%e6%b3%9b%e5%9e%8b%e3%80%91","status":"publish","type":"post","link":"http:\/\/zyg.luchers.cn\/index.php\/2024\/04\/14\/%e6%b3%9b%e5%9e%8b%e3%80%90%e6%b3%9b%e5%9e%8b%e4%bb%8b%e7%bb%8d%e3%80%81%e8%87%aa%e5%ae%9a%e4%b9%89%e6%b3%9b%e5%9e%8b%e3%80%91\/","title":{"rendered":"\u6cdb\u578b\u3010\u6cdb\u578b\u4ecb\u7ecd\u3001\u81ea\u5b9a\u4e49\u6cdb\u578b\u3011"},"content":{"rendered":"

\u7b2c\u5341\u4e94\u7ae0\u3001\u6cdb\u578b<\/h1>\n

\u4e00\u3001\u6cdb\u578b\u7684\u7406\u89e3\u548c\u597d\u5904<\/h3>\n

1\u3001 \u95ee\u9898<\/h4>\n

1\u3001\u4e0d\u80fd\u5bf9\u52a0\u5165\u5230\u96c6\u5408ArrayList\u4e2d\u7684\u6570\u636e\u7c7b\u578b\u8fdb\u884c\u7ea6\u675f\uff08\u4e0d\u5b89\u5168\uff09<\/p>\n

2\u3001\u904d\u5386\u7684\u65f6\u5019\uff0c\u9700\u8981\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\uff0c\u5982\u679c\u96c6\u5408\u4e2d\u7684\u6570\u636e\u5927\uff0c\u4f1a\u5f71\u54cd\u6548\u7387<\/p>\n

2\u3001\u597d\u5904<\/h4>\n

1\u3001\u7f16\u8bd1\u65f6\uff0c\u68c0\u67e5\u6dfb\u52a0\u5143\u7d20\u7684\u7c7b\u578b\uff0c\u63d0\u9ad8\u4e86\u5b89\u5168\u6027<\/p>\n

2\u3001\u51cf\u5c11\u4e86\u7c7b\u578b\u8f6c\u6362\u7684\u6b21\u6570\uff08\u7528\u5230\u5411\u4e0b\u8f6c\u578b\uff09\u63d0\u9ad8\u6548\u7387<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\/\/\u65e0\u6cdb\u578b\nArrayList list = new ArrayList();\n        list.add(new Dog("\u5927\u9ec4",2));\n        list.add(new Dog("\u4e8c\u54c8",3));\n        list.add(new Dog("\u5c0f\u5e03",4));\n\n        for(Object obj:list) {\n            Dog d1 = (Dog)obj;\/\/\u4f7f\u7528\u4e86\u7c7b\u578b\u8f6c\u6362\n            System.out.println(d1.getName());\n        }\n\/\/\u6709\u6cdb\u578b\nArrayList <Dog1> list = new ArrayList<Dog1>();\n        list.add(new Dog1("\u5927\u9ec4",2));\n        list.add(new Dog1("\u4e8c\u54c8",3));\n        list.add(new Dog1("\u5c0f\u5e03",4));\n\/\/        list.add(new Cat("\u54aa\u54aa", 1));\u6dfb\u52a0\u5931\u8d25\n        for(Dog1 dog : list) {\/\/\u7701\u7565\u4e86\u5f3a\u5236\u7c7b\u578b\u8f6c\u6362\n            System.out.println(dog.getName());\n        }\n    }<\/code><\/pre>\n
3\u3001\u6cdb\u578b\u4ecb\u7ecd<\/h3>\n
1\u3001\u6cdb\u578b\u53c8\u79f0\u53c2\u6570\u5316\u7c7b\u578b\uff0c1.5\u7248\u672c\u540e\u7684\uff0c\u89e3\u51b3\u6570\u636e\u7c7b\u578b\u7684\u5b89\u5168\u6027\u95ee\u9898<\/p>\n
2\u3001\u5728\u7c7b\u58f0\u660e\u6216\u5b9e\u4f8b\u5316\u65f6\u53ea\u8981\u6307\u5b9a\u597d\u7684\u9700\u8981\u7684\u5177\u4f53\u7684\u7c7b\u578b\u5373\u53ef<\/p>\n
3\u3001java\u6cdb\u578b\u4f1a\u6709\u63d0\u793a\uff0c\u5982\u679c\u7a0b\u5e8f\u5728\u7f16\u8bd1\u7c7b\u578b\u6ca1\u6709\u53d1\u51fa\u7ecf\u8fc7\uff0c\u8fd0\u884c\u65f6\u5c31\u4e0d\u4f1a\u4ea7\u751fClassCaseException\u7c7b\u578b\u8f6c\u6362\u5f02\u5e38\uff0c\u4ee3\u7801\u66f4\u7b80\u6d01\u3001\u5f3a\u58ee<\/p>\n
4\u3001\u4f5c\u7528\uff1a\u53ef\u4ee5\u5728\u7c7b\u58f0\u660e\u65f6\u901a\u8fc7\u4e00\u4e2a\u6807\u8bc6\u8868\u793a\u7c7b\u4e2d\u67d0\u4e2a\u5c5e\u6027\u7684\u7c7b\u578b\uff0c\u6216\u8005\u662f\u67d0\u4e2a\u65b9\u6cd5\u7684\u8fd4\u56de\u503c\u7c7b\u578b\u3001\u6216\u8005\u662f\u53c2\u6570\u7c7b\u578b\u3002<\/p>\n
\uff081\uff09eg\uff1a<\/p>\n
    public static void main(String[] args) {\n        \/\/ TODO Auto-generated method stub\n        US <String> u  = new US("\u54c8\u5b9d");\n    }\n\nclass US <E> {\/\/\u7c7b\u5b9a\u4e49\u6cdb\u578b\n    E ss;\/\/\u5c5e\u6027\u5b9a\u4e49\u6cdb\u578b\uff0cE\u8868\u793ass\u7684\u6570\u636e\u7c7b\u578b\uff0c\u8be5\u6570\u636e\u7c7b\u578b\u5728\u5b9a\u4e49Persion\u5bf9\u8c61\u65f6\u6307\u5b9a\uff0c\u5728\u7f16\u8bd1\u671f\u95f4\uff0c\u5c31\u786e\u5b9aE\u7684\u7f16\u8bd1\u7c7b\u578b\n\n    public US(E ss) {\/\/E\u4e5f\u53ef\u4ee5\u662f\u53c2\u6570\u7c7b\u578b\n        this.ss=ss;\n    }\n    public E ff() {    \/\/\u65b9\u6cd5\u8fd4\u56de\u7c7b\u578b\u4e5f\u53ef\u4ee5\u5b9a\u4e49\n        return ss;\n    }\n}<\/code><\/pre>\n
4\u3001\u6cdb\u578b\u7684\u8bed\u6cd5<\/h3>\n
4.1\u3001\u6cdb\u578b\u7684\u58f0\u660e<\/h5>\n
1\u3001interface  \u63a5\u53e3 { } \u548cclass\u7c7b<K,v>{}<\/p>\n
2\u3001\u8bf4\u660e<\/p>\n
\uff081\uff09\u5176\u4e2d\uff1aT,K,V \u4e0d\u4ee3\u8868\u503c\uff0c\u800c\u662f\u8868\u793a\u7c7b\u578b\u3002<\/p>\n
\uff082\uff09\u4efb\u610f\u5b57\u6bcd\u90fd\u53ef\u4ee5\u3002\u5e38\u7528T\u8868\u793a\uff0c\u662fType\u7684\u7f29\u5199<\/p>\n
4.2\u3001\u6cdb\u578b\u7684\u5b9e\u4f8b\u5316<\/h5>\n
1\u3001eg<\/p>\n
    public static void main(String[] args) {\n        \/\/ TODO Auto-generated method stub\n        Set <Student> set = new HashSet <Student> ();\n        set.add(new Student("\u50bb\u74dc",11));\n        set.add(new Student("\u6076\u72d7    ",16));\n        set.add(new Student("\u857e\u59c6",18));\n        for(Student student:set) {\n            System.out.println(student);\n        }\n        HashMap<String, Student> hashMap1 = new HashMap<String,Student>();\n        hashMap1.put("ton", new Student("\u61a8\u5305", 20));\n        hashMap1.put("jack", new Student("\u5305\u5305", 28));\n        hashMap1.put("smith", new Student("hsp", 35));\n\/\/        entryset\u53d6\u51fa\u3002\u8fed\u4ee3\u5668\n        Set<Map.Entry<String, Student>> entries = hashMap1.entrySet();\n        Iterator<Map.Entry<String, Student>> iterator = entries.iterator();\n        while(iterator.hasNext()) {\n            Map.Entry<String, Student> next = iterator.next();\n            System.out.println(next.getKey()+"\u2014\u2014"+next.getValue());\n        }\n\n    }<\/code><\/pre>\n
5\u3001\u6cdb\u578b\u4f7f\u7528\u7684\u6ce8\u610f\u4e8b\u9879<\/h3>\n
1\u3001interface  List{}   public  class  HashSet{}<\/p>\n
\uff081\uff09\u8bf4\u660e\uff1aT\uff0cE\u53ea\u80fd\u662f\u5f15\u7528\u7c7b\u578b<\/strong>\uff0c\u4e14\u53ef\u4ee5\u662f\u591a\u4e2a<\/p>\n
\uff082\uff09eg\uff1aint\u9519\u8bef\uff0cint\u662f\u57fa\u672c\u6570\u636e\u7c7b\u578b<\/p>\n
2\u3001\u5728\u6307\u5b9a\u6cdb\u578b\u5177\u4f53\u7c7b\u578b\u540e\uff0c\u53ef\u4ee5\u4f20\u5165\u8be5\u7c7b\u578b\u6216\u5176\u5b50\u7c7b\u7c7b\u578b<\/p>\n
\uff081\uff09\u7406\u89e3\uff1a\u5c31\u662f\u652f\u6301\u4e86\u7ee7\u627f<\/p>\n
3\u3001\u6cdb\u578b\u7684\u5b9a\u4e49\u5f62\u5f0f\u4e24\u79cd<\/p>\n
\uff081\uff09List  list =  new  ArrayList();<\/p>\n
\uff082\uff09  List list =  new  ArrayList<> ();<\/p>\n
\uff083\uff09\u63a8\u8350\uff082\uff09\u5199\u6cd5<\/p>\n
4\u3001\u5982\u679c\u6211\u4eec\u8fd9\u6837\u5199 List  list3  =  new  ArrayList();<\/p>\n
\u9ed8\u8ba4\u7ed9\u5b83\u7684\u6cdb\u578b\u5c31\u662f\u5c31Object\u7c7b\u3002<\/p>\n
6\u3001\u81ea\u5b9a\u4e49\u6cdb\u578b<\/h3>\n
6.1\u3001\u57fa\u672c\u8bed\u6cd5<\/h4>\n
1\u3001class \u7c7b\u540d<T\uff0cR\u2026>{    \/\/\u2026\u4ee3\u8868\u53ef\u4ee5\u591a\u4e2a<\/p>\n
\u200b    \u6210\u5458<\/p>\n
}<\/p>\n
6.2\u3001\u6ce8\u610f\u7ec6\u8282<\/h4>\n
1\u3001\u666e\u901a\u6210\u5458\u53ef\u4ee5\u4f7f\u7528\u6cdb\u578b\uff08\u5c5e\u6027\u3001\u65b9\u6cd5\uff09<\/p>\n
2\u3001\u4f7f\u7528\u6cdb\u578b\u7684\u6570\u7ec4\uff0c\u4e0d\u80fd\u521d\u59cb\u5316<\/p>\n
3\u3001\u9759\u6001\u65b9\u6cd5\u4e2d\u4e0d\u80fd\u4f7f\u7528\u7c7b\u7684\u6cdb\u578b<\/p>\n
4\u3001\u6cdb\u578b\u7c7b\u7684\u7c7b\u578b\uff0c\u662f\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u786e\u5b9a\u7684\uff08\u56e0\u4e3a\u521b\u5efa\u5bf9\u8c61\u65f6\uff0c\u9700\u8981\u6307\u5b9a\u786e\u5b9a\u7c7b\u578b\uff09<\/p>\n
5\u3001\u5982\u679c\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\uff0c\u6ca1\u6709\u6307\u5b9a\u7c7b\u578b\uff0c\u9ed8\u8ba4\u4e3aObject<\/p>\n
6\u3001eg<\/p>\n
class Tiger<T,R,M>{\n    String name;\n    R r;\n    M m;\n    T t;\n    T ts[];\/\/\u53ef\u4ee5\u5b9a\u4e49\uff0c\u4e0d\u80fd\u521d\u59cb\u5316\n\/\/    T[] ts = new T[8]    \u53c2\u6570\u7c7b\u578b\u4e0d\u5141\u8bb8\u76f4\u63a5\u5b9e\u4f8b\u5316\u3002\u56e0\u4e3a\u6570\u7ec4\u5728new\u4e0d\u80fd\u786e\u5b9aT\u7684\u7c7b\u578b\uff0c\u65e0\u6cd5\u5728\u5185\u5b58\u5f00\u8f9f\u7a7a\u95f4\n    public Tiger(String name, R r, M m, T t) {\n        super();\n        this.name = name;\n        this.r = r;\n        this.m = m;\n        this.t = t;\n    }\n\/\/    static R r2; \n\/\/    \u56e0\u4e3a\u9759\u6001\u662f\u548c\u7c7b\u76f8\u5173\u7684\uff0c\u7c7b\u52a0\u8f7d\u65f6\uff0c\u5bf9\u8c61\u4e0d\u52a0\u8f7d\u3002\n\/\/    \u6240\u4ee5\u9759\u6001\u65b9\u6cd5\u548c\u9759\u6001\u5c5e\u6027\u4f7f\u7528\u4e86\u6cdb\u578b\uff0cJVM\u65e0\u6cd5\u5224\u65ad\u5927\u5c0f<\/code><\/pre>\n
7\u3001\u81ea\u5b9a\u4e49\u6cdb\u578b\u63a5\u53e3<\/h3>\n
7.1\u3001\u57fa\u672c\u8bed\u6cd5<\/h4>\n
interface  \u63a5\u53e3\u540d<T\uff0cR\u2026>{    \/\/\u2026\u4ee3\u8868\u53ef\u4ee5\u591a\u4e2a \u6210\u5458<\/p>\n
7.2\u6ce8\u610f\u7ec6\u8282<\/h4>\n
1\u3001\u63a5\u53e3\u4e2d\uff0c\u9759\u6001\u6210\u5458\u4e5f\u4e0d\u80fd\u4f7f\u7528\u6cdb\u578b\uff08\u8fd9\u4e2a\u548c\u6cdb\u578b\u7c7b\u89c4\u5b9a\u4e00\u6837\uff09<\/p>\n
2\u3001\u6cdb\u578b\u63a5\u53e3\u7684\u7c7b\u578b\uff0c\u5728\u7ee7\u627f\u63a5\u53e3\u6216\u8005\u5b9e\u73b0\u63a5\u53e3\u65f6\u786e\u5b9a<\/p>\n
3\u3001\u6ca1\u6709\u6307\u5b9a\u7c7b\u578b\uff0c\u9ed8\u8ba4\u4e3aObject<\/p>\n
7.3\u3001eg<\/h4>\n
interface IA extends IUsb<String, Double>{    \n}\n\/\/\u5f53\u6211\u4eec\u53bb\u5b9e\u73b0IA\u63a5\u53e3\u65f6\uff0c\u56e0\u4e3aIA\u5728\u7ee7\u627fIUse \u63a5\u53e3\u65f6\uff0c\u6307\u5b9a\u4e86U\u4e3aString\uff0cR\u4e3aDdouble\u7c7b\u578b\nclass AA implements IA{\n    @Override\n    public Double get(String u) {\n        \/\/ TODO Auto-generated method stub\n        return null;\n    }\n    @Override\n    public void hi(Double r) {\n        \/\/ TODO Auto-generated method stub\n    }\n    @Override\n    public void run(Double r1, Double r2, String u1, String u2) {\n        \/\/ TODO Auto-generated method stub\n    }\n}\nclass CC implements IUsb{    \/\/\u5982\u679c\u6ca1\u5199\uff0c\u6cdb\u578b\u9ed8\u8ba4\u4e3aObject\n    @Override\n    public Object get(Object u) {\n        \/\/ TODO Auto-generated method stub\n        return null;\n    }\n    @Override\n    public void hi(Object r) {\n        \/\/ TODO Auto-generated method stub    \n    }\n    @Override\n    public void run(Object r1, Object r2, Object u1, Object u2) {\n        \/\/ TODO Auto-generated method stub    \n    }\n}\ninterface IUsb<U,R>{\n    int n =10;\n\/\/    U name; \u4e0d\u80fd\u8fd9\u6837\u4f7f\u7528\n\/\/    \u666e\u901a\u65b9\u6cd5\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u63a5\u53e3\u6cdb\u578b\n    R get(U u);\n    void hi(R r);\n    void run(R r1,R r2,U u1,U u2);\n\/\/    \u5728jdk8\u4e2d\uff0c\u53ef\u4ee5\u5728\u63a5\u53e3\u4e2d\uff0c\u4f7f\u7528\u9ed8\u8ba4\u65b9\u6cd5\uff0c\u4e5f\u662f\u53ef\u4ee5\u8fd9\u6837\u4f7f\u7528\u53d1\u90a3\u4e9b\n    default R method(U u) {\n        return null;\n    }\n}<\/code><\/pre>\n
8\u3001\u81ea\u5b9a\u4e49\u6cdb\u578b\u65b9\u6cd5<\/h3>\n
8.1\u57fa\u672c\u8bed\u6cd5<\/h4>\n
1\u3001\u4fee\u9970\u7b26  <T,R\u2026> \u8fd4\u56de\u7c7b\u578b  \u65b9\u6cd5\u540d\uff08\u53c2\u6570\u5217\u8868\uff09{<\/p>\n
}<\/p>\n
8.2\u3001\u6ce8\u610f\u7ec6\u8282<\/h4>\n
1\u3001\u6cdb\u578b\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5b9a\u4e49\u5728\u666e\u901a\u7c7b\u4e2d\uff0c\u4e5f\u53ef\u4ee5\u5b9a\u4e49\u5728\u6cdb\u578b\u7c7b\u4e2d<\/p>\n
2\u3001\u6cdb\u578b\u65b9\u6cd5\u88ab\u8c03\u7528\u65f6\uff0c\u7c7b\u578b\u786e\u8ba4<\/p>\n
3\u3001public  void  eat(E  e){ }\u3002\u4fee\u9970\u7b26\u540e\u6ca1\u6709<T\uff0cR\u2026>eat \u65b9\u6cd5\u4e0d\u662f\u6cdb\u578b\u7c7b\u578b\uff0c\u800c\u662f\u4f7f\u7528\u4e86\u6cdb\u578b\u3002<\/p>\n
8.3\u3001eg<\/h4>\n
        Car car = new Car(); \n        car.fly("\u5b9d\u9a6c", 100);\/\/\u5f53\u8c03\u7528\u65b9\u6cd5\u65f6\uff0c\u4f20\u5165\u53c2\u6570\uff0c\u7f16\u8bd1\u5668\uff0c\u5c31\u4f1a\u786e\u5b9a\u7c7b\u578b\n    }\n\n}\nclass Car{    \/\/\u666e\u901a\u7c7b\n    public void run() {\/\/\u666e\u901a\u65b9\u6cd5    \n    }\n\/\/    \u8bf4\u660e\n\/\/    1\u3001<T,R>\u5c31\u662f\u6cdb\u578b\n\/\/    2\u3001\u662f\u63d0\u4f9b\u7ed9fly\u4f7f\u7528\u7684\n    public <T,R>void fly(T t,R r){\/\/\u6cdb\u578b\u65b9\u6cd5    \n        System.out.println(t.getClass());\/\/String\u7c7b\u578b\n        System.out.println(r.getClass());\/\/Integer\u7c7b\u578b\n    }\n}\nclass Fish<T,R>{\n    public void run() {\/\/\u666e\u901a\u65b9\u6cd5\n    }\n    public <U,M> void eat() {\n    }\n\/\/    \u8bf4\u660e\n\/\/    1\u3001\u4e0b\u9762hi\u65b9\u6cd5\u4e0d\u662f\u6cdb\u578b\u65b9\u6cd5\n\/\/    2\u3001\u662f\u666e\u901a\u65b9\u6cd5\u4f7f\u7528\u7c7b\u5b9a\u4e49\u7684\u6cdb\u578b\n    public void hi(T t) {\n    }\n\/\/    \u6cdb\u578b\u65b9\u6cd5\uff0c\u53ef\u4ee5\u4f7f\u7528\u7c7b\u58f0\u660e\u7684\u6cdb\u578b\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528\u81ea\u5df1\u58f0\u660e\u6cdb\u578b\n    public <K> void hello(R r,K k) {\n    }\n}<\/code><\/pre>\n
9\u3001\u6cdb\u578b\u7684\u7ee7\u627f\u548c\u901a\u914d\u7b26<\/h3>\n
1\u3001\u6cdb\u578b\u4e0d\u5177\u5907\u7ee7\u627f\u6027<\/p>\n
\uff081\uff09List    list  =  new  ArrayList  ();<\/p>\n
2\u3001<?>\uff1a\u652f\u6301\u4efb\u610f\u6cdb\u578b\u7c7b\u578b<\/p>\n
3\u3001<? extends A>\uff1a\u652f\u6301A\u7c7b\u4ee5\u53caA\u7c7b\u7684\u5b50\u7c7b\uff0c\u89c4\u5b9a\u4e86\u6cdb\u578b\u7684\u4e0a\u7ebf<\/p>\n
4\u3001<? super A>\uff1a\u652f\u6301A\u7c7b\u4ee5\u53caA\u7c7b\u7684\u7236\u7c7b\uff0c\u4e0d\u9650\u4e8e\u76f4\u63a5\u7236\u7c7b\uff0c\u89c4\u5b9a\u4e86\u6cdb\u578b\u7684\u4e0b\u9650\u3002<\/p>\n
5\u3001eg<\/p>\n
\/\/        \u6cdb\u578b\u6ca1\u6709\u7ee7\u627f\u6027\n\/\/        List <Object> list = new ArrayList<>();\n    List<Object> list1 = new ArrayList<>();\n    List<String> list2 = new ArrayList<>();\n    List<AA1> list3 = new ArrayList<>();\n    List<BB1> list4 = new ArrayList<>();\n    List<CC1> list5 = new ArrayList<>();    \n\n\/\/    \u8fd9\u79cd\u65b9\u6cd5<?>,\u5168\u90e8\u52a0\u7684\u8fdb\u53bb\n    printCollection1(list1);\n    printCollection1(list2);\n    printCollection1(list3);\n    printCollection1(list4);\n    printCollection1(list5);\n\n\/\/    \u8fd9\u79cd\u65b9\u6cd5 List<? extends AA> c \u8868\u793a \u4e0a\u9650\uff0c\u53ef\u4ee5\u63a5\u53d7AA\u6216\u8005AA\u5b50\u7c7b\n    printCollection2(list1);\/\/\u4e0d\u884c\n    printCollection2(list2);\/\/\u4e0d\u884c\n    printCollection2(list3);\/\/\u53ef\u4ee5\n    printCollection2(list4);\/\/\u53ef\u4ee5\n    printCollection2(list5);\/\/\u53ef\u4ee5\n\n\/\/    \u8fd9\u79cd\u65b9\u6cd5 List<? super \n    printCollection3(list1);\/\/\u53ef\u4ee5\n    printCollection3(list2);\/\/\u4e0d\u884c\n    printCollection3(list3);\/\/\u53ef\u4ee5\n    printCollection3(list4);\/\/\u4e0d\u884c\n    printCollection3(list5);\/\/\u4e0d\u884c\n    }\n    public static void printCollection1(List<?>c) {    \/\/\u901a\u914d\u7b26\uff0c\u53d6\u51fa\u65f6\uff0c\u5c31\u662fObject\n        for(Object object : c ) {\n            System.out.println(object);\n        }\n    }\n\/\/    ? extends AA \u8868\u793a \u4e0a\u9650\uff0c\u53ef\u4ee5\u63a5\u53d7AA\u6216\u8005AA\u5b50\u7c7b\n    public static void printCollection2(List<?extends AA1>  c) {    \/\/\u901a\u914d\u7b26\uff0c\u53d6\u51fa\u65f6\uff0c\u5c31\u662fObject\n        for(Object object : c ) {\n            System.out.println(object);\n        }\n    } \n\/\/    ?super \u5b50\u7c7b\u7c7b\u540dAA1\uff1a\u652f\u6301AA\u7c7b\u4ee5\u53caAA\u7c7b\u7684\u7236\u7c7b\uff0c\u4e0d\u9650\u76f4\u63a5\u7236\u7c7b\u3002\n    public static void printCollection3(List<? super AA1>c) {    \/\/\u901a\u914d\u7b26\uff0c\u53d6\u51fa\u65f6\uff0c\u5c31\u662fObject\n        for(Object object : c ) {\n            System.out.println(object);\n        }\n    }\n}\nclass AA1{\n}\nclass BB1 extends AA1{    \n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
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