java中的contains（）方法

import java.util.ArrayList;
import java.util.Collection;
/*
* boolean contains(object o);判断集合中是否包含某个元素。
* boolean remove(object o);删除集合集合中个某个元素
*/
//contains方法底层调用的书equals方法，所有存储在集合的中元素应该重写equals()方法。
public class ColletcionTest02 {
public static void main(String[] args){
Collection c = new ArrayList();
c.add(new Integer(1));
System.out.println(c.contains(1));
//添加Customer
Customer cus1 = new Customer("zhangsan",14);
Customer cus2 = new Customer("zhangsan",14);
c.add(cus1);
System.out.println(c.contains(cus2));
}
}

public class Customer {
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Customer(String name, int age) {
super();
this.name = name;
this.age = age;
}
public Customer(){

}
public String toString(){
return "name=" + name +" "+"age="+ age;
}
//重写了equal方法
public boolean equals(Object o){
if(this==o){
return true;
}else{
if(o instanceof Customer){
Customer co = (Customer)o;
if(co.name.equals(this.name)&&co.age==this.age){
return true;
}
}
}
return false;
}
}