一、Object类

java中，所有类都直接或间接继承自java.lang.Object类，可以说Object是java中所有类的祖先即根类
java中任何类都继承了Object类中的方法，主要有
toStrring()
public String toString() {

// TODO Auto-generated method stub
//return super.toString();                    //默认打印包名+类内存地址
return "person meaage:" + name + address;    //方法重写

}

System.out.println(s.toString());
/*
person meaage:xiaowei甲3214
*/

equals()

public boolean equals(Object arg0) {

// TODO Auto-generated method stub
//return super.equals(arg0);       //默认比较的是地址
Person s = (Person)arg0;            //强转
if(this.address == s.address && this.name == s.name){//比较成员变量
    return true;
}else{
    return false;
}

}

System.out.println(s.equals(s2));
/*
true
*/

hashcode()
clone()
getClass()
finalize()

二、代码演示

class Person{//class 相当于c语言的struct

String name;
String address;

public void printInfo(){
    System.out.println("name=" + name);
}

private void printAddr(){
    System.out.println("address=" + address);
}

public String toString() {
    // TODO Auto-generated method stub
    //return super.toString();                    //默认打印包名+类内存地址
    return "person meaage:" + name + address;    //方法重写
}

public boolean equals(Object arg0) {
    // TODO Auto-generated method stub
    //return super.equals(arg0);       //默认比较的是地址
    Person s = (Person)arg0;            //强转
    if(this.address == s.address && this.name == s.name){//比较成员变量
        return true;
    }else{
        return false;
    }
}

}

public class Test {

public static void main(String[] args) {    
    Person s = new Person();
    s.name = "xiaowei";
    s.address = "甲3214";
    
    Person s2 = new Person();
    s2.name = "xiaowei";
    s2.address = "甲3214";
    
    System.out.println(s.equals(s2));
    System.out.println(s.toString());
}

}

/*
true
person meaage:xiaowei甲3214
*/