toString()

public class Student {
    private String name;
    private int age;


    public Student() {
    }

    public Student(String name, int age) {
        this.name = name;
        this.age = 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;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

public class Test {
    public static void main(String[] args) {
        Student student = new Student("张三", 100);
        //Object 默认的toString方法没有用
        //需要子类覆写 toString方法
        System.out.println(student.toString());
        //控制台打印对象时  toString可以忽略
        System.out.println(student);
    }
}

equals()

/**
* 比较name和age全相同就返回true
*/
@Override
public boolean equals(Object o) {
  if (this == o) {
      return true;
   };
   if (!(o instanceof Student)) {
     return false;
   }
   Student student = (Student) o;
    return getAge() == student.getAge() && getName().equals(student.getName());
}

@Override
public int hashCode() {
   return Objects.hash(getName(), getAge());
}
Student student1 = new Student("李四", 88);
Student student2 = new Student("李四", 88);


//Object 默认equals的方法 用的时== 比较的时对象地址
boolean flag= student1.equals(student2);
System.out.println(flag);

hashCode()