62 Java 重写类的equals()方法

package new20140415;

class Student {

String name;
String idStr;

public Student() {
};

public Student(String name, String idStr) {

this.name = name;
this.idStr = idStr;
}

//重写equals方法，提供自定义的相等标准
public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public String getIdStr() {
return idStr;
}

public void setIdStr(String idStr) {
this.idStr = idStr;
}

public boolean equals(Object obj){
//如果对象为同一个对象的相等标准
if(this==obj){
return true;
}
//当obj部位null，且它是student类的实例时
if(obj != null &&obj.getClass()==Student.class)
{
Student stuObj=(Student)obj;
if(stuObj.getIdStr().equals(this.getIdStr()))
{
return true;
}
}

return false;

}

}

public class Test4 {
public static void main(String[] args) {

Student stu1=new Student("李三", "001");
Student stu2=new Student("李三", "001");
Student stu3=new Student("张颖", "009");
System.out.println(stu1.equals(stu2));
System.out.println(stu1.equals(stu3));
}
}