需求：

实力类的属性值在修改时变化了 ，需要将具体对象，什么属性 ，变化前后的值记录下来 ，形成变更记录；

例如 AppParty 党员实力类 的属性民族 从汉族变更成傣族

具体展现形式如下：

重点难点

在于不干扰业务的情况下 ，不传参数，仅仅通过切面 获取到具体对象，什么属性 ，变化前后的值；灵活利用反射获取实例；
主要通过切面获取方法和参数；应用反射获取相应的属性和属性值
细节和问题很多，经过多次完善和更新，已经能够应用到所有的情况的变更记录
具体的操作都在ChangeLogAspect ；重点都在代码注释中。

整体思路：

创建自定义注解 FieldDesc 对实力类做注释，最基本的是获取属性的名称 ，如nation --民族 ；其次通过type，来区分 属于一下那种类型 ，并做相应的处理，例如修改时 前端参数和数据库对应的值是字典值 比如1-汉族，12-傣族，要将1和12都转换成对应的汉字；又例如变更的是地区id–42，要将42转换成对应的湖北省； 创建自定义注解changeLog，加到具体的更新方法，当更新方法被调用，切面方法ChangeLogAspect会对获取变更的对象和变更前后的属性值进行遍历对比，将变化的值转换后存入数据库

app_changelog 存放变更记录的表

CREATE TABLE `app_changelog` (`id` varchar(32) NOT NULL COMMENT '主键',`object_id` varchar(32) DEFAULT NULL COMMENT '对象ID',`unit_info` varchar(100) DEFAULT NULL COMMENT '单位信息',`type` varchar(10) DEFAULT NULL COMMENT '类型，0更新，1删除，2新增',`user_id` varchar(32) DEFAULT NULL COMMENT '用户ID',`user_name` varchar(50) DEFAULT NULL COMMENT '用户名称',`field_name` varchar(30) DEFAULT NULL COMMENT '字段名',`before_change_value` varchar(255) DEFAULT NULL COMMENT '变更前值',`after_change_value` varchar(255) DEFAULT NULL COMMENT '变更后值',`create_time` datetime DEFAULT NULL COMMENT '创建时间',PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='变更记录';

自定义注解changeLog

添加到server或者controller的update方法上面 作为切点

package com.sinoecare.vc2.app.annotations;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface ChangeLog {String value() default "";
}

自定义注解FieldDesc

添加到POJO类的属性上 针对不同的情况做对应的处理

package com.sinoecare.vc2.common.core.annotations;import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface FieldDesc {/*** 变更记录的字段名称* @return*/String name()  default "";/*** 变更记录的字段类型* “dict” :字典* “area”:地区id，需要转换全名的* “pass” ：不插入变更记录的字段* “checkbox” ：带字典的多选框* “date” ：日期类型* “photo” ：不展示细节，只提示修改* @return*/String type() default "";/*** 变更记录类型为字典 “type” 时，才需要此字段* @return*/String dictValue() default "";/*** 变更记录类型为Date 时  确定精度   year   day   second* @return*/String patten() default "day";/*** 变更记录类型为photo 时  “对活动封面图进行了修改”* @return*/String photo() default "图片已修改";
}

pojo类

例如 AppParty 党员实力类 的属性民族

	/*** 民族*/@FieldDesc(name = "民族", type = "dict", dictValue = "nation")private String nation;

切面方法

兼容Controller 如果注解加在Controller上 则转换到对应的serverImpl实例

package com.sinoecare.vc2.app.aop;import cn.hutool.core.annotation.AnnotationUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.ReflectUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.annotation.TableField;
import com.sinoecare.vc2.app.annotations.ChangeLog;
import com.sinoecare.vc2.app.mapper.AppChangeLogMapper;
import com.sinoecare.vc2.app.remoteService.RemoteSysService;
import com.sinoecare.vc2.common.core.annotations.FieldDesc;
import com.sinoecare.vc2.common.core.bean.*;
import com.sinoecare.vc2.common.core.util.R;
import com.sinoecare.vc2.common.core.util.ReflectBeanUtil;
import com.sinoecare.vc2.common.core.vo.DictDetailVO;
import com.sinoecare.vc2.common.security.service.VillcloudUser;
import com.sinoecare.vc2.common.security.util.SecurityUtils;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import java.io.Serializable;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAccessor;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;@Component
@Aspect
@Slf4j
public class ChangeLogAspect {@Autowiredprivate AppChangeLogMapper appChangeLogMapper;@Autowiredprivate RemoteSysService remoteSysService;@Pointcut(value = "@annotation(com.sinoecare.vc2.app.annotations.ChangeLog)")public void aspect() {}@Before("@annotation(changeLog)")public void Around(JoinPoint joinPoint, ChangeLog changeLog) {try {ChangeLog aspect = ((MethodSignature) joinPoint.getSignature()).getMethod().getAnnotation(ChangeLog.class);VillcloudUser securityUser = SecurityUtils.getUser();AppChangeLog alog = new AppChangeLog();//得到当前业务层实现类类型Class<?> implClass = joinPoint.getThis().getClass();Object target = joinPoint.getTarget();String objClassName = implClass.getName();Object serviceImpl = target;//兼容Controller 如果注解加在Controller上  则转换到对应的serverImpl实例if (objClassName.contains("Controller")) {objClassName = objClassName.substring(objClassName.lastIndexOf(".") + 1, objClassName.indexOf("$"));objClassName = objClassName.replace("Controller", "Service");objClassName = (new StringBuilder()).append(Character.toLowerCase(objClassName.charAt(0))).append(objClassName.substring(1)).toString();serviceImpl = ReflectUtil.getFieldValue(target, objClassName);}//得到执行方法名String MethodName = joinPoint.getSignature().getName();//得到传入参数             ******更新和新增传参为对象，删除传参为主键idObject[] args = joinPoint.getArgs();Object afterObject = args[0];//得到传入参数的类类型Class<?> PareamClass = afterObject.getClass();//参数的idString id = null;String objectId = null;List<String> ids = null;if (afterObject instanceof String) {id = (String) afterObject;} else if (afterObject instanceof List) {ids = (List<String>) afterObject;} else {id = ReflectUtil.invoke(afterObject, "getId");//特殊业务处理if (afterObject instanceof AppFarmerToilet) {objectId = ReflectUtil.invoke(afterObject, "getFarmerId");} else if (afterObject instanceof AppFarmerOthers) {objectId = ReflectUtil.invoke(afterObject, "getFarmerId");}  else if (afterObject instanceof AppPartyWorkInfo) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");} else if (afterObject instanceof AppPartyFiveStar) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");} else if (afterObject instanceof AppPartyDisciplinaryInfo) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");}}//将通用信息先赋给alog对象alog.setId(IdUtil.simpleUUID());alog.setObjectId(id);alog.setUserId(securityUser.getId());alog.setUserName(securityUser.getRealName());alog.setCreateTime(LocalDateTime.now());//将单位id替换到单位名R<SysUnit> response = remoteSysService.getUnitById(securityUser.getUnitId());if (response.getData() != null) {alog.setUnitInfo(response.getData().getName());}//判断调用的方法为update/add/delete  处理相应的逻辑if (MethodName.startsWith("update")|| MethodName.startsWith("modify")|| MethodName.startsWith("change")|| MethodName.startsWith("add")|| MethodName.startsWith("save")|| MethodName.startsWith("insert")|| MethodName.startsWith("create")) {//  传了id  说明是更新if (StrUtil.isNotEmpty(id)) {//将类型转化成对应的释义   0 更新，1  删除，2  新增 3.图片alog.setType("0");//根据afterObject的id，调用主键查询方法，查询修改前的对象Method selectByPrimaryKey = serviceImpl.getClass().getMethod("getById", Serializable.class);Object beforeObject = selectByPrimaryKey.invoke(serviceImpl, id);
//					Object beforeObject = ReflectUtil.invoke(implClass, "getById", (Serializable) id);//得到参数的所有getter方法，遍历，不为null且beforeName 不等于 afterName 的属性就是被修改的值，则插入操作日志Class<?> OriginalClass = beforeObject.getClass();Field[] fields = ReflectUtil.getFields(OriginalClass);//要处理的行政区划的相关字段 K-字段 V-行政区划 lanlan 2019-4-24Map<String, String[]> areaCodes = new HashMap<>();fieldRow:for (Field field : fields) {boolean isDate = false;String fieldName = field.getName();//主键的getter方法跳过if ("id".equals(field.getName()) || "serialVersionUID".equals(field.getName())) {continue;}String getterMethodName = ReflectBeanUtil.getGetterMethodName(fieldName, PareamClass);Object objectBefore = ReflectBeanUtil.invokeMethodByName(beforeObject, getterMethodName);Object objectAfter = ReflectBeanUtil.invokeMethodByName(afterObject, getterMethodName);String beforeName = null;String afterName = null;//属性的值为Data，则转换成stringSimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd hh:mm:ss");if (objectBefore instanceof String) {beforeName = (String) objectBefore;} else if (objectBefore instanceof Date) {beforeName = sdf.format(objectBefore);} else if (objectBefore instanceof LocalDateTime) {beforeName = df.format((TemporalAccessor) objectBefore);} else if (objectBefore instanceof Integer) {beforeName = objectBefore.toString();}else if (objectBefore instanceof Double) {beforeName = objectBefore.toString();}if (objectAfter instanceof String) {afterName = (String) objectAfter;} else if (objectAfter instanceof Date) {afterName = sdf.format(objectAfter);isDate = true;} else if (objectAfter instanceof LocalDateTime) {afterName = df.format((TemporalAccessor) objectAfter);isDate = true;} else if (objectAfter instanceof Integer) {afterName = objectAfter.toString();}else if (objectAfter instanceof Double) {afterName = objectAfter.toString();}//未修改的字段直接跳过,不插入日志if (afterName == null || (StrUtil.isBlank(afterName) && beforeName == null) || beforeName == afterName || afterName.equals(beforeName)) {continue;}//换算金额的变更记录if ("cost".equals(fieldName)) {if ("0".equals(beforeName)) {beforeName = "000";}if ("0".equals(afterName)) {afterName = "000";}String template = "{}.{}元";String before1 = beforeName.substring(0, (beforeName.length() - 2));String before2 = beforeName.substring(beforeName.length() - 2);beforeName = StrUtil.format(template, before1, before2);String after1 = afterName.substring(0, (afterName.length() - 2));String after2 = afterName.substring(afterName.length() - 2);afterName = StrUtil.format(template, after1, after2);}
/*						//取得字段的ApiModelProperty注解if (field.isAnnotationPresent(ApiModelProperty.class)) {//是否使用ApiModelProperty注解Map<String, Object> annotationValueMap = AnnotationUtil.getAnnotationValueMap(field, ApiModelProperty.class);if (annotationValueMap != null) {fieldName = annotationValueMap.get("value") != null ? annotationValueMap.get("value").toString() : "";}}*///取得字段的TableField注解  如果属性exist  为false的话  表示该字段不是数据库字段则需要跳过if (field.isAnnotationPresent(TableField.class)) {Map<String, Object> annotationValueMap = AnnotationUtil.getAnnotationValueMap(field, TableField.class);if (annotationValueMap != null && annotationValueMap.get("exist") != null) {boolean flag = Boolean.valueOf(annotationValueMap.get("exist").toString());if (!flag) {continue fieldRow;}}}//取得字段的FieldDesc注解if (field.isAnnotationPresent(FieldDesc.class)) {//是否使用FieldDesc注解Map<String, Object> annotationValueMap = AnnotationUtil.getAnnotationValueMap(field, FieldDesc.class);fieldName = annotationValueMap.get("name") != null ? annotationValueMap.get("name").toString() : "";String fieldType = annotationValueMap.get("type") != null ? annotationValueMap.get("type").toString() : "";String DictfieldName = annotationValueMap.get("dictValue") != null ? annotationValueMap.get("dictValue").toString() : "";String patten = annotationValueMap.get("patten") != null ? annotationValueMap.get("patten").toString() : "";String photo = annotationValueMap.get("photo") != null ? annotationValueMap.get("photo").toString() : "";//根据注解的内容做相应处理switch (fieldType) {case "dict":DictDetailVO dictDetailVO = remoteSysService.queryDictDetailByCode(DictfieldName).getData();//是有字典的值，将属性的字母转换成对应的释义 如 “sfz” 转换成 “身份证”
//									fieldName = dictDetailVO.getName();//查询字典，将单选多选中的值转换成对应的释义  如性别 0 ， 1 转换成 女 ， 男List<SysDictionaryDetail> sysDictionaryDetails = dictDetailVO.getDictionaryDetails();if (sysDictionaryDetails != null && sysDictionaryDetails.size() > 0) {before:for (SysDictionaryDetail sysDictionaryDetail : sysDictionaryDetails) {if (beforeName != null && beforeName.equals(sysDictionaryDetail.getDictValue())) {beforeName = sysDictionaryDetail.getDictName();break before;}}after:for (SysDictionaryDetail sysDictionaryDetail : sysDictionaryDetails) {if (afterName != null && afterName.equals(sysDictionaryDetail.getDictValue())) {afterName = sysDictionaryDetail.getDictName();break after;}}}break;//注解为地区id类型  需要将地区编码转换成地区全名case "area":beforeName = StrUtil.isBlank(beforeName) ? "" : remoteSysService.queryAreaFullName(beforeName).getData();afterName = StrUtil.isBlank(afterName) ? "" : remoteSysService.queryAreaFullName(afterName).getData();if (beforeName.equals(afterName)) {continue fieldRow;}break;//注解为带字典的多选框case "checkbox":String[] befores = JSONUtil.parseArray(beforeName).toArray(new String[0]);beforeName = "";String[] afters = JSONUtil.parseArray(afterName).toArray(new String[0]);afterName = "";DictDetailVO checkDetailVO = remoteSysService.queryDictDetailByCode(DictfieldName).getData();//是有字典的值，将属性的字母转换成对应的释义 如 “sfz” 转换成 “身份证”fieldName = checkDetailVO.getName();//查询字典，将单选多选中的值转换成对应的释义  如性别 0 ， 1 转换成 女 ， 男List<SysDictionaryDetail> checkDictionaryDetails = checkDetailVO.getDictionaryDetails();if (checkDictionaryDetails != null && checkDictionaryDetails.size() > 0) {for (String beforePart : befores) {for (SysDictionaryDetail sysDictionaryDetail : checkDictionaryDetails) {if (beforePart != null && beforePart.equals(sysDictionaryDetail.getDictValue())) {beforePart = sysDictionaryDetail.getDictName();beforeName = beforeName + beforePart + ",";break;}}}if (beforeName.endsWith(",")) {beforeName = beforeName.substring(0, beforeName.length() - 1);}for (String afterPart : afters) {for (SysDictionaryDetail sysDictionaryDetail : checkDictionaryDetails) {if (afterPart != null && afterPart.equals(sysDictionaryDetail.getDictValue())) {afterPart = sysDictionaryDetail.getDictName();afterName = afterName + afterPart + ",";break;}}}if (afterName.endsWith(",")) {afterName = afterName.substring(0, afterName.length() - 1);}}break;case "date":switch (patten) {case "year":if (StrUtil.isBlank(beforeName)) {beforeName = "";} else {beforeName = beforeName.substring(0, 4);}afterName = afterName.substring(0, 4);break;case "day":if (StrUtil.isBlank(beforeName)) {beforeName = "";} else {beforeName = beforeName.substring(0, 10);}afterName = afterName.substring(0, 10);break;case "second":default:break;}break;//注解为跳过 该字段   不插入变更记录case "photo":alog.setType("3");beforeName = "";afterName = photo;break;//不展示细节，只提示修改case "pass":continue fieldRow;//进入default说明注解什么都没写或者注解不正确   跳过不插入变更记录default:break ;}} else {//无FieldDesc时 处理正常的Date类型的变更记录if (isDate) {if (StrUtil.isNotEmpty(beforeName)) {beforeName = beforeName.substring(0, 10);}if (StrUtil.isNotEmpty(afterName)) {afterName = afterName.substring(0, 10);}}}//子表变更记录关联到主表上if (StrUtil.isNotEmpty(objectId)) {alog.setObjectId(objectId);}//插入更新日志alog.setId(IdUtil.simpleUUID());alog.setFieldName(fieldName);alog.setBeforeChangeValue(beforeName);alog.setAfterChangeValue(afterName);appChangeLogMapper.insert(alog);alog.setType("0");}} else {//如果没穿id  则说明是新增List<String> fields = ReflectBeanUtil.getFields(afterObject.getClass());for (String field : fields) {if ("xm".equals(field) || "name".equals(field)) {String getterMethodName = ReflectBeanUtil.getGetterMethodName(field, afterObject.getClass());String fieldValue = (String) ReflectBeanUtil.invokeMethodByName(afterObject, getterMethodName);//新增的对象名alog.setFieldName(fieldValue);}if ("level".equals(field)) {String getterMethodName = ReflectBeanUtil.getGetterMethodName(field, afterObject.getClass());Integer fieldValue = (Integer) ReflectBeanUtil.invokeMethodByName(afterObject, getterMethodName);//新增的对象名alog.setAfterChangeValue(fieldValue + "星党员");}if ("company".equals(field)) {String getterMethodName = ReflectBeanUtil.getGetterMethodName(field, afterObject.getClass());String fieldValue = (String) ReflectBeanUtil.invokeMethodByName(afterObject, getterMethodName);//新增的对象名alog.setAfterChangeValue(fieldValue);}if ("disciplinaryInfo".equals(field)) {String getterMethodName = ReflectBeanUtil.getGetterMethodName(field, afterObject.getClass());String fieldValue = (String) ReflectBeanUtil.invokeMethodByName(afterObject, getterMethodName);//新增的对象名alog.setAfterChangeValue(fieldValue);}}if (afterObject instanceof AppPartyFiveStar) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");alog.setFieldName("五星党员信息");} else if (afterObject instanceof AppPartyWorkInfo) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");alog.setFieldName("党员工作信息");} else if (afterObject instanceof AppPartyDisciplinaryInfo) {objectId = ReflectUtil.invoke(afterObject, "getPartyId");alog.setFieldName("党员违纪信息");}alog.setObjectId(objectId);//将类型转化成对应的释义   0 更新，1  删除，2  新增alog.setType("2");//插入新增日志appChangeLogMapper.insert(alog);}} else if (MethodName.startsWith("delete") || MethodName.startsWith("batchDelete") ||MethodName.startsWith("remove") || MethodName.startsWith("drop")) {//批量删除遍历主键for (String currentId : ids) {//根据id，调用主键查询方法，查询删除前的对象Method selectByPrimaryKey = serviceImpl.getClass().getMethod("getById", Serializable.class);Object beforeObject = selectByPrimaryKey.invoke(serviceImpl, currentId);List<String> fields = ReflectBeanUtil.getFields(beforeObject.getClass());for (String field : fields) {if ("xm".equals(field) || "name".equals(field)) {String getterMethodName = ReflectBeanUtil.getGetterMethodName(field, beforeObject.getClass());String fieldValue = (String) ReflectBeanUtil.invokeMethodByName(beforeObject, getterMethodName);//删除的对象名alog.setFieldName(fieldValue);}}alog.setId(IdUtil.simpleUUID());alog.setObjectId(currentId);//将类型转化成对应的释义   0 更新，1  删除，2  新增alog.setType("1");//插入删除日志appChangeLogMapper.insert(alog);}}
//			Object proceed = joinPoint.proceed();} catch (Exception e) {log.info(e.getMessage());throw new RuntimeException(e);} catch (Throwable throwable) {throwable.printStackTrace();}}}

切面关键在于通过反射获取对应的类、方法和属性、属性值

反射工具类/也可以用hutool的反射工具类

package com.sinoecare.vc2.common.core.util;import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;/*** JavaBeanUtil<br>* Description: 反射相关方法** @author lanlan* @version 1.4* @create 2019/1/22*/
public class ReflectBeanUtil {/*** 根据类名反射创建对象* @param name 类名* @return 对象* @throws Exception*/public static Object getInstance(String name) throws Exception {Class<?> cls = Class.forName(name);return cls.newInstance();}/*** 获取包含所有父类字段在内的所有字段* @param clazz 要获取字段的类* @return  字段名集合*/public static List<String> getFields(Class clazz){List<Field> fields = new ArrayList<>();//为null时到达了父类的最高级Objectwhile (clazz.getSuperclass() != null){fields.addAll(Arrays.asList(clazz.getDeclaredFields()));//得到父类并赋值给自己clazz = clazz.getSuperclass();}List<String> fieldNames = new ArrayList<>();for (Field field : fields) {fieldNames.add(field.getName());}return fieldNames;}/*** 根据属性名称和java类型，获取对应的getter方法名* @param property* @param* @return*/public static String getGetterMethodName(String property, Class clazz) {StringBuilder sb = new StringBuilder();sb.append(property);if (Character.isLowerCase(sb.charAt(0))) {if (sb.length() == 1 || !Character.isUpperCase(sb.charAt(1))) {sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));}}if ("boolean".equals(clazz.getName())) {sb.insert(0, "is");} else {sb.insert(0, "get");}return sb.toString();}/*** 根据属性名称获取对应的setter方法名称* @param property* @return*/public static String getSetterMethodName(String property) {StringBuilder sb = new StringBuilder();sb.append(property);if (Character.isLowerCase(sb.charAt(0))) {if (sb.length() == 1 || !Character.isUpperCase(sb.charAt(1))) {sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));}}sb.insert(0, "set");return sb.toString();}/*** 根据方法名调用无参方法* @param object 要执行该方法的对象* @param methodName    方法名* @return*/public static Object invokeMethodByName(Object object, String methodName) throws Exception {Method method = object.getClass().getMethod(methodName);method.setAccessible(true);Object o = method.invoke(object);return o;}
}