Java中equals、hashCode方法重载(@Override)及其健壮性判断

• 方法一

    @Override
    public boolean equals(Object o) {
    
    
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        if (age != person.age) return false;
        return name.equals(person.name);
    }

    @Override
    public int hashCode() {
    
    
        int result = name.hashCode();
        result = 31 * result + age;
        return result;
    }

• 方法二

   @Override
    public boolean equals(Object o) {
    
    
        if (this == o) return true;
        if (!(o instanceof Person)) return false;

        Person person = (Person) o;

        if (getAge() != person.getAge()) return false;
        return getName().equals(person.getName());
    }

    @Override
    public int hashCode() {
    
    
        int result = getName().hashCode();
        result = 31 * result + getAge();
        return result;
    }

• 方法三