==与equals的区别

        //基本数据类型的比较
        int num1 = 10;
        int num2 = 10;
        System.out.println(num1 == num2);   //true
        //引用数据类型的比较
        String s1 = "chance";
        String s2 = "chance";
        System.out.println(s1 == s2);        //true
        System.out.println(s1.equals(s2));    //true
        //String类中==与equals的比较
        String s3 = new String("chance");     
        String s4 = new String("chance");
        System.out.println(s3 == s4);        //false
        System.out.println(s3.equals(s4));    //true
        //非String类中==与equals类型的比较
        Scanner scanner = new Scanner(System.in);      
        Scanner scanner2 = new Scanner(System.in);
        System.out.println(scanner.equals(scanner2));       //false
        Scanner sc = scanner;
        System.out.println(scanner.equals(sc));            //true

https://blog.csdn.net/chance2015/article/details/51427304