String引用的值改变了为什么赋值的值没变

Question

代码跟运行结果如下 public static void main(String[] agrs){         String s1 = new String("aaa");         String s2 = s1;         System.out.println("s1=" + s1);         System.out.println("s2=" + s2);         s1 = "bbb";         System.out.println("s1=" + s1);         System.out.println("s2=" + s2);     }s1=aaa s2=aaa s1=bbb s2=aaa