场景

在项目中，会出现一些对sql处理的需求，如果sql操作很多，为了简化处理，可以在sql执行的时候加入一个拦截器，并对将要执行的sql进行统一的处理。

这里已使用了mybatisplus客户端为例的实现方式。

代码实现

• maven引入依赖jar，数据库配置就不写这了。

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.3</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.5</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

• 自定义拦截器

import com.baomidou.mybatisplus.extension.plugins.inner.InnerInterceptor;
import lombok.extern.slf4j.Slf4j;
import net.sf.jsqlparser.JSQLParserException;
import net.sf.jsqlparser.parser.CCJSqlParserUtil;
import net.sf.jsqlparser.statement.Statement;
import net.sf.jsqlparser.util.TablesNamesFinder;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
import java.util.Properties;

@Slf4j
public class LizzMybatisIntercepts implements InnerInterceptor {
    @Override
    public boolean willDoQuery(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) throws SQLException {
        log.info("#####willDoQuery");
        return false;
    }

    @Override
    public void beforeQuery(Executor executor, MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, BoundSql boundSql) throws SQLException {
        log.info("#####beforeQuery");
    }
   
    @Override
    public boolean willDoUpdate(Executor executor, MappedStatement ms, Object parameter) throws SQLException {
        log.info("#####willDoUpdate");
        // 一堆sql处理仅供参考
        BoundSql boundSql = ms.getBoundSql(parameter);
        ms.getSqlSource().getClass();
        String sql = boundSql.getSql();
        Statement statement = null;
        try {
            statement =  CCJSqlParserUtil.parse(sql);
        } catch (JSQLParserException e) {
            e.printStackTrace();
        }
        TablesNamesFinder tablesNamesFinder = new TablesNamesFinder();
        List<String> tableList = tablesNamesFinder.getTableList(statement);
        log.info("sql:{}",sql);
        return false;
    }

    @Override
    public void beforeUpdate(Executor executor, MappedStatement ms, Object parameter) throws SQLException {
        log.info("#####beforeUpdate");
    }

    @Override
    public void beforePrepare(StatementHandler sh, Connection connection, Integer transactionTimeout) {
        log.info("#####beforePrepare");
    }

    @Override
    public void beforeGetBoundSql(StatementHandler sh) {
        log.info("#####beforeGetBoundSql");
    }

    @Override
    public void setProperties(Properties properties) {
        log.info("#####setProperties");
    }
}

• 增加拦截器

@Configuration
public class CipherMybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        
        // 自定义拦截器，先添加先执行。
        interceptor.addInnerInterceptor(new LizzMybatisIntercepts());
        // 自带分页拦截器
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}