equals（）方法的运用

//自定义一个类，比较两个对象的属性值都相等的情况下，返回true的话，就需要重新Object类的equals（Object obj）方法
//equals()方法的运用

package exer1;
    
public class TestOrder{
        public static void main(String[] args) {
            Order o1=new Order(111,"跳舞");
            Order o2=new Order(111,"跳舞");
            System.out.println(o1==o2);
            System.out.println(o1.equals(o2));
        }
    }

 class Order {
    private int orderId;
    private String orderName;
    public int getOrderId() {
        return orderId;
    }
    public Order(int orderId, String orderName) {
        super();
        this.orderId = orderId;
        this.orderName = orderName;
    }
    public void setOrderId(int orderId) {
        this.orderId = orderId;
    }
    
    public String getOrderName() {
        return orderName;
    }
    public void setOrderName(String orderName) {
        this.orderName = orderName;
    }
    //比较两个order对象的属性是否完全相同，如果相同返回true，反之false
    public boolean equals(Object obj){
        if(this==obj){
            return true;
        }else if(obj instanceof Order){
            Order o1=(Order)obj;
            return this.orderId==o1.orderId
                    && this.orderName.equals(orderName);
        }else
            return false;
    }
//系统自带的，以后做开发时候直接用

public boolean equals(Object obj) {
// if (this == obj)
// return true;
// if (obj == null)
// return false;
// if (getClass() != obj.getClass())
// return false;
// Order other = (Order) obj;
// if (orderId != other.orderId)
// return false;
// if (orderName == null) {
// if (other.orderName != null)
// return false;
// } else if (!orderName.equals(other.orderName))
// return false;
// return true;
// }

}