String和常量池值的变化

public static void main(String[] args) {    Integer i1 = new Integer(1);    Integer i2 = new Integer(1);    // i1,i2分别位于堆中不同的内存空间    System.out.println("i1 == i2:" + (i1 == i2));// 输出false    String s1 = "china";    String s2 = "china";    String ss1 = new String("china");    String ss2 = new String("china");    System.out.println("s1 == s2:" + (s1 == s2));    System.out.println("ss1 == ss2" + (ss1 == ss2));    System.out.println("s1 == ss2" + (s1 == ss2));    // 利用Java反射机制改变string的值    Field f = null;    Field f1 = null;    try {      f = s1.getClass().getDeclaredField("value");      f1 = ss1.getClass().getDeclaredField("value");    } catch (NoSuchFieldException e) {      e.printStackTrace();    }    f.setAccessible(true);    f1.setAccessible(true);    try {      f.set(s1, new char[] { 'c', 'h', 'i', 'n', 'b' });      f1.set(ss1, new char[] { 'c', 'h', 'i', 'n', 'b' });    } catch (Exception e) {      e.printStackTrace();    }    System.out.println("改变后的s1的值：" + s1);    System.out.println("s2的值是：" + s2);    System.out.println("ss1的值是：" + ss1);    System.out.println("s1 == s2:" + (s1 == s2));    System.out.println("ss1 == ss2" + (ss1 == ss2));    System.out.println("s1 == ss2" + (s1 == ss2));    System.out.println("============分割线==================");    System.out.println("改变后的ss1的值：" + ss1);    System.out.println("ss2的值是：" + ss2);  }

打印的结果：

i1 == i2:false
s1 == s2:true
ss1 == ss2false
s1 == ss2false
改变后的s1的值：chinb
s2的值是：chinb
ss1的值是：chinb
s1 == s2:true
ss1 == ss2false
s1 == ss2false
============分割线==================
改变后的ss1的值：chinb
ss2的值是：china

原标题：String和常量池值的变化

关键词：string