public static void main(String[] args) { String s1 = "abcd"; String s2 = new String("abcd"); System.out.println(s2.intern() == s1); String s3 = "ab"; String s4 = "cd"; String s5 = s3 + s4; final String s6 = s3 + s4; System.out.println("s5 == s6 :" +(s5 == s6)); System.out.println("s1 == s6 :" +(s1 == s6)); System.out.println(s1 == s2); System.out.println(s1.equals(s2)); }
有时间研究一下