基于Mybatis拦截器开发自定义拦截器，实现记录数据表最后更新时间

场景：
记录有过增删改操作的数据表及最后更新时间，实现数据增量同步。

解决方案：基于Mybatis拦截器开发自定义拦截器

1.实现Mybatis拦截器Interceptor，重写intercept方法

2.使用druid解析sql，获取sql中涉及的表

3.实现自定义逻辑

 拦截器代码如下：

package com.cms.filter;

import com.alibaba.druid.sql.SQLUtils;
import com.alibaba.druid.sql.ast.SQLStatement;
import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlSchemaStatVisitor;
import com.alibaba.druid.stat.TableStat;
import com.alibaba.druid.util.JdbcConstants;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.cms.common.utils.StringUtils;
import com.cms.common.utils.spring.SpringUtils;
import com.cms.domain.entity.systemData.SystemData;
import com.cms.mapper.systemData.SystemDataMapper;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.*;
import org.springframework.stereotype.Component;

import java.util.*;
import java.util.stream.Collectors;

/**
 * @author daixin
 * @version 1.0
 * @description: TODO
 * @date 2022/9/28 13:48
 */
@Slf4j
@Component
@Intercepts({@Signature(type = Executor.class, method = "update", args = {MappedStatement.class, Object.class})})
public class ExecutorDataVaryInterceptor implements Interceptor {

    /**
     * 拦截方法逻辑
     */
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        //方法参数
        Object[] args = invocation.getArgs();
        MappedStatement mappedStatement = (MappedStatement) args[0];
        Object parameterObject = args[1];

        //获取Sql命令类型UNKNOWN, INSERT, UPDATE, DELETE, SELECT, FLUSH
        SqlCommandType sqlCommandType = mappedStatement.getSqlCommandType();
        String commandType = sqlCommandType.name();
        //获取拦截的Sql
        BoundSql boundSql = mappedStatement.getSqlSource().getBoundSql(parameterObject);
        String sql = boundSql.getSql();
        //判断新增和修改操作，执行自定义逻辑
        if("INSERT".equalsIgnoreCase(commandType)||"UPDATE".equalsIgnoreCase(commandType)){
            //解析Sql, 获取涉及的数据表
            List<String> tableNameList =  getTableNameBySql(sql);
            //判断sql执行的数据表是否在需要管理的白名单内
            QueryWrapper<SystemData> queryWrapper = new QueryWrapper<>();
            queryWrapper.lambda().in(SystemData::getTableName,tableNameList);
            SystemDataMapper systemDataMapper = SpringUtils.getBean(SystemDataMapper.class);
            List<SystemData> systemDataList = systemDataMapper.selectList(queryWrapper);
            //在白名单内的表, 管理更新时间
            if(!StringUtils.isEmpty(systemDataList)){
                List<String> updateTimeTables = systemDataList.stream().map(SystemData::getTableName).collect(Collectors.toList());
                systemDataMapper.saveUpdateTimeBatch(updateTimeTables);
            }
        }
        Object result = invocation.proceed();
        return result;
    }

    /**
     * 解析Sql，获取涉及的数据表
     * @param sql
     * @return
     */
    private List<String> getTableNameBySql(String sql) {
        try {
            String dbType = String.valueOf(JdbcConstants.MYSQL);
            List<String> tableNameList = new ArrayList<>();
            log.info("格式化后的sql:{}",SQLUtils.format(sql, dbType));

            List<SQLStatement> sqlStatementList = SQLUtils.parseStatements(sql, dbType);
            if (CollectionUtils.isEmpty(sqlStatementList)) {
                return Collections.emptyList();
            }
            for (SQLStatement sqlStatement : sqlStatementList) {
                MySqlSchemaStatVisitor visitor = new MySqlSchemaStatVisitor();
                sqlStatement.accept(visitor);
                Map<TableStat.Name, TableStat> tables = visitor.getTables();
                for (TableStat.Name name : tables.keySet()) {
                    String tableName = name.getName();
                    if (StringUtils.isNotBlank(tableName)) {
                        tableNameList.add(tableName);
                    }
                }
            }
            log.info("解析sql获取的表名:{}",tableNameList);
            return tableNameList;
        } catch (Exception e) {
            log.error("===================异常SQL=================={}",sql);
            log.error(e.getMessage(),e);
        }
        return Collections.emptyList();
    }

}

mybatis-config.xml注入拦截器

<plugins>
    <plugin interceptor="com.cms.filter.ExecutorDataVaryInterceptor">
    </plugin>
</plugins>

spring boot集成druid所需依赖

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>${druid.version}</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.8</version>
    <scope>compile</scope>
</dependency>

同理，也可实现日志收集等功能。