jdk1.5泛型的应用

package com.jdk150.bean;

import java.util.ArrayList;
import java.util.List;


public class GenericsFoo<T> {

private T foo;

public T getFoo() {
return foo;
}

public void setFoo(T foo) {
this.foo = foo;
}


public static void main(String[] args){
GenericsFoo<Integer> gfi = new GenericsFoo<Integer>();
gfi.setFoo(new Integer(123));
int i = gfi.getFoo();

GenericsFoo<String> gfs = new GenericsFoo<String>();
gfs.setFoo("hello!");
String s = gfs.getFoo();

GenericsFoo<Boolean> gfb = new GenericsFoo<Boolean>();
gfb.setFoo(false);
boolean b = gfb.getFoo();

//传统的list什么对象都能放
List list = new ArrayList();
list.add(i);
list.add(s);
list.add(b);

for(int j=0;j<list.size();j++){
System.out.println(list.get(j));
}

//泛型list只能放所定义的类型对象
List<Integer> l = new ArrayList<Integer>();
for(int k=0;k<10;k++){
l.add(k+1);
}

// l.add("hello"); //错误的添加

for(int x=0;x<l.size();x++){
System.out.println(l.get(x));
}


}
}