Java自定义mybatis拦截器实现创建人等相关信息自动填充

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在实际项目开发中，我们可能需要在mapper层插入相应的数据，而这些数据在各个表基本都有，比如
创建时间，更新时间，创建人，更新人这些，但是又不想在每个业务中都去设置这些值，那么我们就可以使用mybatis拦截器实现数据自动填充。

一、如何实现？
1.首先添加mybatis相关依赖。

        <dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.0.1</version></dependency>

2.自定义mybatis拦截器。

import cn.hutool.core.date.DateUtil;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.session.defaults.DefaultSqlSession.StrictMap;
import org.springframework.stereotype.Component;import java.lang.reflect.Field;
import java.util.*;
@Slf4j
@Component
@Intercepts({ @Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }) })
public class MybatisInterceptor implements Interceptor {private static  final String DATETYPE="java.util.Date";private static  final String STRINGTYPE="java.lang.String";@Overridepublic Object intercept(Invocation invocation) throws Throwable {MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[0];// 获取sql执行类型：insert、update、select、deleteSqlCommandType sqlCommandType = mappedStatement.getSqlCommandType();Object parameter = invocation.getArgs()[1];if (parameter == null) {return invocation.proceed();}//获取当前登录用户idString userId = TokenUtil.getConcurrentUserId();log.debug(" userId is {}....",userId);// 当sql为新增或更新类型时，自动填充操作人相关信息if (SqlCommandType.INSERT == sqlCommandType || SqlCommandType.UPDATE == sqlCommandType) {replaceEntityProperty(parameter,userId,sqlCommandType);}return invocation.proceed();}private void replaceEntityProperty(Object parameter,String userId, SqlCommandType sqlCommandType ) {// StrictMapif (parameter instanceof StrictMap) {replaceStrictMap((StrictMap) parameter,userId,sqlCommandType);} else if (parameter instanceof Map) {replaceMap((Map) parameter,userId,sqlCommandType);} else {replace(parameter,userId,sqlCommandType);}}private void replace(Object parameter,String userId,SqlCommandType sqlCommandType ) {if(SqlCommandType.INSERT == sqlCommandType){Field[] fields = getAllFields(parameter);for (Field field : fields) {try {//先设置可访问 获取值校验field.setAccessible(true);Object o = field.get(parameter);//如果不为空 则跳过 为空才设置默认值//异步执行时 取不到用户信息 这时需要手动设置if(Objects.nonNull(o)){field.setAccessible(false);continue;}if ("deleted".equals(field.getName())) {field.set(parameter, Integer.valueOf("0"));field.setAccessible(false);}else if ("createdBy".equals(field.getName())) {field.set(parameter, userId);field.setAccessible(false);}else if ("createdTime".equals(field.getName())) {String type = field.getType().getName();if(DATETYPE.equals(type)){field.set(parameter, new Date());}else if(STRINGTYPE.equals(type)) {field.set(parameter, DateUtil.formatDateTime(new Date()));}field.setAccessible(false);}else {updateProperty(parameter, field, userId);}} catch (Exception e) {log.error("failed to insert data, exception = ", e);}}}else if(SqlCommandType.UPDATE == sqlCommandType){Field[] fields = getAllFields(parameter);for (Field field : fields) {try {//先设置可访问 获取值校验field.setAccessible(true);Object o = field.get(parameter);//如果不为空 则跳过 为空才设置默认值//异步执行时 取不到用户信息 这时需要手动设置if(Objects.nonNull(o)){field.setAccessible(false);continue;}//更新时只判断是否更新的属性updateProperty(parameter, field, userId);}catch (Exception e){log.error("failed to update data, exception = ", e);}}}}private void replaceStrictMap(StrictMap map, String userId, SqlCommandType sqlCommandType ) {if (map.containsKey("collection")) {Object collection = map.get("collection");for (Object t : (Collection) collection) {replace(t,userId,sqlCommandType);}} else if (map.containsKey("array")) {Object collection = map.get("array");for (Object t : (Object[]) collection) {replace(t,userId,sqlCommandType);}}}private void replaceMap(Map map,String userId, SqlCommandType sqlCommandType) {for (Object value : map.values()) {replace(value,userId,sqlCommandType);}}private void updateProperty(Object parameter, Field field, String userId) throws IllegalAccessException {if ("updatedBy".equals(field.getName())) {field.set(parameter, userId);field.setAccessible(false);}else if ("updatedTime".equals(field.getName())) {String type = field.getType().getName();if (DATETYPE.equals(type)) {field.set(parameter, new Date());} else if (STRINGTYPE.equals(type)) {field.set(parameter, DateUtil.formatDateTime(new Date()));}field.setAccessible(false);}else {//其他属性什么也不做field.setAccessible(false);}}@Overridepublic Object plugin(Object target) {return Plugin.wrap(target, this);}@Overridepublic void setProperties(Properties properties) {}/*** 获取类的所有属性，包括父类*/private Field[] getAllFields(Object object) {Class<?> clazz = object.getClass();List<Field> fieldList = new ArrayList<>();while (clazz != null) {fieldList.addAll(new ArrayList<>(Arrays.asList(clazz.getDeclaredFields())));clazz = clazz.getSuperclass();}Field[] fields = new Field[fieldList.size()];fieldList.toArray(fields);return fields;}
}

下面是TokenUtil类，用于获取当前登录用户id。

@Slf4j
public class TokenUtil {public static String getConcurrentUserId() {ServletRequestAttributes requestAttributes = (ServletRequestAttributes)RequestContextHolder.getRequestAttributes();if (Objects.isNull(requestAttributes)) {return "";} else {HttpServletRequest request = requestAttributes.getRequest();String userId = request.getHeader("x-userId");if (!StringUtils.isBlank(userId)) {return userId;} else {Object attribute = request.getAttribute("x-userId");return Objects.nonNull(attribute) ? attribute.toString() : "";}}}
}