public static void main(String[] args) {
A a = new A();
a.setUserName("a");
a.setPassword("p");
a.setQq("q");
a.setWechat("w");

 A b = new A();
 b.setUserName("a");
 b.setPassword("p");
 b.setQq("q");
 b.setWechat("ww");

 //只是比較兩個對象是否相等，那么直接重寫equals方法
 System.out.println( a.equals(b));

 try {
  Map<String, String> maps = compare( a, b );
  System.out.println();
 } catch (Exception e) {
  e.printStackTrace();
 }
}


public static <T> Map<String, String> compare(T obj1, T Obj2)
  throws Exception {

 Map<String, String> result = new HashMap<String, String>();

 Field[] fs = obj1.getClass().getDeclaredFields();
 for (Field f : fs) {
  f.setAccessible(true);
  Object v1 = f.get(obj1);
  Object v2 = f.get(Obj2);
  if( ! equals(v1, v2) ){
   result.put(f.getName(), String.valueOf(equals(v1, v2)));

  }
 }
 return result;
}

public static boolean equals(Object obj1, Object obj2) {

 if (obj1 == obj2) {
  return true;
 }
 if (obj1 == null || obj2 == null) {
  return false;
 }
 return obj1.equals(obj2);
}