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
