✨ Introducing new features. String test

crossoverJie · crossoverJie · commit 4d01e00e6036 · 2018-03-09T17:30:11.000+08:00
diff --git a/src/main/java/com/crossoverjie/basic/StringTest.java b/src/main/java/com/crossoverjie/basic/StringTest.java
@@ -11,13 +11,29 @@
  */
 public class StringTest {
 
-    public static void main(String[] args) throws NoSuchFieldException {
+    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
         String a = "123";
+        //这里的 a 和 b  都是同一个对象，指向同一个字符串常量池对象。
+        String b = "123" ;
+        String c = new String("123") ;
+
+        System.out.println("a=b:" + (a == b));
+        System.out.println("a=c:" + (a == c));
+
         System.out.println("a=" + a);
 
         a = "456";
         System.out.println("a=" + a);
 
-        Field value = a.getClass().getField("value");
+
+        //用反射的方式改变字符串的值
+        Field value = a.getClass().getDeclaredField("value");
+        //改变 value 的访问属性
+        value.setAccessible(true) ;
+
+        char[] values = (char[]) value.get(a);
+        values[0] = '9' ;
+
+        System.out.println(a);
     }
 }
