原文网址Mybatis-Plus--解决自动填充无效的问题-CSDN博客简介本文介绍Mybatis-Plus解决自动填充无效的问题。问题描述mybatis-plus方法里如果入参有entity实体都能自动填充字段。如果入参没有entity实体有的能自动填充有的不能自动填充。可以自动填充的场景userService.removeById(id);userService.removeBatchByIds(idList);不能自动填充的场景userService.lambdaUpdate().eq(User::getUserName, username).remove();解决方法解析SQL自动添加SET语句。package com.example.demo.config.mybatis; import com.baomidou.mybatisplus.core.toolkit.PluginUtils; import org.apache.ibatis.executor.statement.StatementHandler; import org.apache.ibatis.mapping.*; import org.apache.ibatis.plugin.*; import org.apache.ibatis.reflection.MetaObject; import org.apache.ibatis.reflection.SystemMetaObject; import org.springframework.stereotype.Component; import java.sql.Connection; import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.regex.Matcher; import java.util.regex.Pattern; Intercepts({Signature( type StatementHandler.class, method prepare, args {Connection.class, Integer.class} )}) Component public class MybatisFillUpdateSqlInterceptor implements Interceptor { // 定义正则表达式用于提取 SET 部分的字段名 private static final Pattern SET_PATTERN Pattern.compile(UPDATE\\s[^\\s]\\s(SET)); Override public Object intercept(Invocation invocation) throws Throwable { StatementHandler statementHandler PluginUtils.realTarget(invocation.getTarget()); MetaObject metaObject SystemMetaObject.forObject(statementHandler); MappedStatement mappedStatement (MappedStatement) metaObject.getValue(delegate.mappedStatement); if (SqlCommandType.UPDATE mappedStatement.getSqlCommandType() StatementType.CALLABLE ! mappedStatement.getStatementType()) { BoundSql boundSql (BoundSql) metaObject.getValue(delegate.boundSql); // 获取已经构造好的SQL String sql boundSql.getSql(); // 获取映射的参数 ListParameterMapping mappings new ArrayList(boundSql.getParameterMappings()); // 假如参数中不包含要构造的参数手动写入 MapString, String fieldsMap customFieldMap(); for (EntryString, String map : fieldsMap.entrySet()) { String fieldKey map.getKey(); Matcher setMatcher SET_PATTERN.matcher(sql); // 找到UPDATE才处理 if (setMatcher.find()) { Pattern fieldPattern Pattern.compile(UPDATE\\s[^\\s]\\s(SET)\\s[^\\s]* fieldKey [^\\s]); Matcher fieldMatcher fieldPattern.matcher(sql); if (!fieldMatcher.find()) { // 原SQL有此字段则不处理 int indexOfSet setMatcher.start(1);; String sqlPart fieldKey map.getValue() , ; sql sql.substring(0, indexOfSet) SET sqlPart sql.substring(indexOfSet 4); } } } metaObject.setValue(delegate.boundSql.sql, sql); metaObject.setValue(delegate.boundSql.parameterMappings, mappings); } return invocation.proceed(); } Override public Object plugin(Object target) { return target instanceof StatementHandler ? Plugin.wrap(target, this) : target; } private MapString, String customFieldMap() { MapString, String params new HashMap(); String now LocalDateTime.now().format(DateTimeFormatter.ofPattern(yyyy-MM-dd HH:mm:ss)); params.put(update_time, now); return params; } }