业务场景

更新User信息后，需要收集哪些字段的哪些值被更新了。

思路

比较originUser和newUser，收集值不同的属性以及变化前后的值。

代码实现

public static Map<String, Map<String, Object>> getChange(Object originObject, Object newObject) {// 存在为null比价就没意义了if (ObjectUtils.anyNull(originObject, newObject)) {return new HashMap<>();}// 不同类型无法比较if (ObjectUtils.notEqual(originObject.getClass(), newObject.getClass())) {return new HashMap<>();}// 内容都相等所以没必要比较if (Objects.deepEquals(originObject, newObject)) {return new HashMap<>();}Map<String, Map<String, Object>> res = Maps.newHashMap();Field[] declaredFields = originObject.getClass().getDeclaredFields();for (Field field : declaredFields) {// 检查Field是否为合成字段、如果该字段是合成字段则不进行比较if (field.isSynthetic()) {continue;}// serialVersionUID适用于java序列化机制,非业务属性if ("serialVersionUID".equals(field.getName())) {continue;}// 实现方式1// field.setAccessible(true);// Object o = field.get(originObject);// Object n = field.get(originObject);// 实现方式2PropertyDescriptor propertyDescriptor = null;try {propertyDescriptor = new PropertyDescriptor(field.getName(), originObject.getClass());Method readMethod = propertyDescriptor.getReadMethod();Object originValue = readMethod.invoke(originObject);Object newValue = readMethod.invoke(newObject);if (!Objects.deepEquals(originValue, newValue)) {// 值不相等的话记录属性和值HashMap<String, Object> keyValue = new HashMap();keyValue.put("origin", originValue);keyValue.put("new", newValue);res.put(field.getName(), keyValue);}} catch (IntrospectionException | IllegalAccessException | InvocationTargetException e) {log.error("getChange occur error" + e.getMessage());}}return res;}

测试验证

public class MethodUtilsTest {@Testpublic void getChangeNoChange() {User user1 = new User();user1.setName("user2");user1.setAge("19");user1.setNum("123456");User user2 = new User();user2.setName("user2");user2.setAge("19");user2.setNum("123456");Map<String, Map<String, Object>> change = MethodUtils.getChange(user1, user2);Assert.assertEquals("{}", change.toString());}@Testpublic void getChangeWithChange() {User user1 = new User();user1.setName("user1");user1.setAge("19");user1.setNum("123456");User user2 = new User();user2.setName("user2");user2.setAge("18");user2.setNum("123457");Map<String, Map<String, Object>> change = MethodUtils.getChange(user1, user2);Assert.assertEquals("{num={new=123457, origin=123456}, name={new=user2, origin=user1}, age={new=18, origin=19}}", change.toString());}@Datastatic class User {private String name;private String age;private String num;}
}

参考

对象被更新后、获取更新了的属性和值