String-intern方法举例分析其含义

 之后重新理解这个知识点时，又写了一些小例子

        String a1 = new String("str01") ;
        String a2 = "str01" ;
        System.out.println(a1 == a2) ;//false

        String a1 = new String("str01") ;
        a1.intern() ;
        String a2 = "str01" ;
        System.out.println(a1 == a2) ;//false

        String a1 = new String("str") + new String("01") ;
        String a2 = "str01" ;
        System.out.println(a1 == a2) ;//fasle

        String a1 = new String("str") + new String("01") ;
        a1.intern() ;
        String a2 = "str01" ;
        System.out.println(a1 == a2) ;//true

　　　　 String s0 = "kvill" ;
        String s1 = new String("kvill") ;
        String s2 = new String("kvill") ;
        System.out.println(s0 == s1);//false
        s1.intern() ;
        s2 = s2.intern() ;
        System.out.println(s0 == s1) ;//false
        System.out.println(s0 == s1.intern()) ;//true
        System.out.println(s0 == s2) ;//true

        String s1 = new String("kvill") +new String("kvill");
        String s2 = s1.intern() ;
        System.out.println(s2 == s1) ;//  true    

        String s1 = new String("kvill") +new String("kvill");
        s1.intern() ;
        String s2 = "kvillkvill" ;
        System.out.println(s2 == s1) ;//true