电脑无法识别USB解决办法

package com.zj.hashset.test;

import java.util.HashSet;

/**
* 功能:重写equals和hashCode方法,让相同姓名的用户不能重复加入HashSet
* @author zhengjiong
* time:2011-9-14 下午11:52:44
*/
public class HashSet_Test {

public static void main(String[] args) {

People p1 = new People("zhangsan");
People p2 = new People("zhangsan");

System.out.println(p1.hashCode());
System.out.println(p2.hashCode());

HashSet set = new HashSet();
set.add(p1);//HashSet会自动调用hashcode方法,List不会
set.add(p2);

System.out.println(set);

}
}
class People {
String name;

public People(String name){
this.name = name;
}

@Override
public int hashCode() {
return this.name.hashCode();
}

@Override
public boolean equals(Object obj) {
if(this == obj){
return true;
}
if(obj != null)
{
if(obj instanceof People){
return this.name.equals(((People)obj).name) ? true : false;
}
}
return false;
}
}