java中的泛型的一些常見例子

1、java中的泛型的一些常見例子public vo name(t name) = name; public v getage() return age; public void setage(v age) this.age = age; private t name; private v age; public ic void main(sing args) hello string, integer he = new hello string, integer he.setage(10); he.setname("rollen holt"); syste

2、m.out.print(he.getname() + " " + he.getage(); * author rollen-holt 泛型類的構造辦法定義 class hello t, v hello(t name, v age) this.age = age; = name; public t getname() return name; public v getage() return age; private t name; private v age; public static void main(string args) hello stri

3、ng,integer he=new hello string,integer ("rollen",12); system.out.println(he.getname()+" "+he.getage(); * author rollen-holt 用法通配符 class info t info(t name) = name; private t name; class hello public static void fution(info ? temp) system.out.println("內容： "+tem

4、p); public static void main(string args) info string demo=new info string ("rollen"); function(demo); * author rollen-holt 泛型上限 class info t info(t age) this.age=age; private t age; class hello public static void function(info ? tends number temp) system.out.println("內容"+ temp);

5、public static void main(string args) info integer demo=new info integer function(demo); * author rollen-holt 泛型下限 class info t info(t age) this.age=age; private t age; class hello public static void function(info ? per string temp) system.out.println("內容"+ temp); public static void main(st

6、ring args) / 此處只能用法string 或者object info string demo=new info string ("rollen"); function(demo); * author rollen-holt 泛型和子類繼承的限制 class info t class hello public static void main(string args) info string demo1=new info string info object demo2=new info object /demo2=demo1; 此處錯誤 * 上面的例子解釋，一個類

7、的子類可以通過多態(tài)性被其父類實例化 * 但是在泛型操作中，子類的泛型類型是無法被其父類的泛型類型實例化的。 假如允許上面的條語句的話，會浮現(xiàn)： exception in thread "main" java.lang.error: unresolv compilation problem: type mismatch: cannot convert from info string to info object at hello.main(hello.java:12) 泛型接口的兩種實現(xiàn)： * author rollen-holt 泛型接口的實現(xiàn)1 interface in

8、fo t public void say(); / 挺直在子類之后聲明泛型 class hello t implements info t public static void main(string args) info string demo = new hello string demo.say(); public void say() system.out.println("hello"); * author rollen-holt 泛型接口的實現(xiàn)2 interface info t public void say(); / 在子類實現(xiàn)的接口中明確給出泛型類型 cl

9、ass hello implements info string public static void main(string args) info string demo = new hello(); demo.say(); public void say() system.out.println("hello"); * author rollen-holt 用法泛型通一傳入?yún)?shù)的類型 class info t private t var; public t getvar() return var; public void setvar(t var) this.var =

10、 var; public string tostring() return this.var.tostring(); class hello public static void main(string args) info string demo1=new info string info string demo2=new info string demo1.setvar("rollen"); demo2.setvar("holt"); printa(demo1, demo2); / 此處傳遞的都是同一個string類型的 public static

11、t void printadd(info t demo1, info t demo2) system.out.println(demo1.getvar()+" "+demo2.getvar(); 否則的話如下所示：浮現(xiàn)錯誤： * author rollen-holt 用法泛型通一傳入?yún)?shù)的類型 class info t private t var; public t getvar() return var; public void setvar(t var) this.var = var; public string tostring() return this.var.t

12、ostring(); class hello public static void main(string args) info string demo1=new info string info integer demo2=new info integer demo1.setvar("rollen"); demo2.setvar(30); /此處調用錯誤 printadd(demo1, demo2); / 此處傳遞的都是同一個string類型的 public static t void printadd(info t demo1, info t demo2) system.out.println(demo1.getvar()+" "+demo2.getvar(); exception in thread "main" java.lang.error