不可变类练习

10.23

不可变类练习

代码练习：

代码部分：

public final class Address
{
private final String detail;
private final String postCode;

//在构造方法里初始化两个实例属性
public Address()
{
this.detail = "";
this.postCode = "";

}
public Address(String detail , String postCode)
{
this.detail = detail;
this.postCode = postCode;
}
//仅为两个实例属性提供getter方法
public String getDetail()
{
return this.detail;
}

public String getPostCode()
{
return this.postCode;
}
//重写equals方法，判断两个对象是否相等。
public boolean equals(Object obj)
{
if (obj instanceof Address)
{
Address ad = (Address)obj;
if (this.getDetail().equals(ad.getDetail()) && this.getPostCode().equals(ad.getPostCode()))
{
return true;
}
}
return false;
}
public int hashCode()
{
return detail.hashCode() + postCode.hashCode();
}
}