MyBatis列印SQL執行時間

1、plugins

MyBatis官網對於plugins的描述是這樣的：

MyBatis allows you to intercept calls to at certain points within the execution of a mapped statement. By default, MyBatis allows plug-ins to intercept method calls of:

• Executor (update, query, flushStatements, commit, rollback, getTransaction, close, isClosed)
• ParameterHandler (getParameterObject, setParameters)
• ResultSetHandler (handleResultSets, handleOutputParameters)
• StatementHandler (prepare, parameterize, batch, update, query)

The details of these classes methods can be discovered by looking at the full method signature of each, and the source code which is available with each MyBatis release. You should understand the behaviour of the method you’re overriding, assuming you’re doing something more than just monitoring calls. If you attempt to modify or override the behaviour of a given method, you’re likely to break the core of MyBatis. These are low level classes and methods, so use plug-ins with caution.

Using plug-ins is pretty simple given the power they provide. Simply implement the Interceptor interface, being sure to specify the signatures you want to intercept.

// ExamplePlugin.java
@Intercepts({@Signature(
  type= Executor.class,
  method = "update",
  args = {MappedStatement.class,Object.class})})
public class ExamplePlugin implements Interceptor {
  public Object intercept(Invocation invocation) throws Throwable {
    return invocation.proceed();
  }
  public Object plugin(Object target) {
    return Plugin.wrap(target, this);
  }
  public void setProperties(Properties properties) {
  }
}

<!-- mybatis-config.xml -->
<plugins>
  <plugin interceptor="org.mybatis.example.ExamplePlugin">
    <property name="someProperty" value="100"/>
  </plugin>
</plugins>

The plug-in above will intercept all calls to the "update" method on the Executor instance, which is an internal object responsible for the low level execution of mapped statements.

NOTE Overriding the Configuration Class

In addition to modifying core MyBatis behaviour with plugins, you can also override the Configuration class entirely. Simply extend it and override any methods inside, and pass it into the call to the SqlSessionFactoryBuilder.build(myConfig) method. Again though, this could have a severe impact on the behaviour of MyBatis, so use caution.

 

2、定義一個Interceptor

package com.cjs.boot.interceptor;

import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.session.ResultHandler;

import java.sql.Statement;
import java.util.Properties;

@Slf4j
@Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class})})
public class SqlStatementInterceptor implements Interceptor {
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        long startTime = System.currentTimeMillis();
        try {
            return invocation.proceed();
        } finally {
            long endTime = System.currentTimeMillis();

            StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
            BoundSql boundSql = statementHandler.getBoundSql();
            String sql = boundSql.getSql();
            sql = sql.replace("\n", "").replace("\t", "").replaceAll("\\s+", " ");

            log.info("執行SQL: [{}]花費{}ms", sql, (endTime - startTime));

        }
    }

    @Override
    public Object plugin(Object target) {
        return Plugin.wrap(target, this);
    }

    @Override
    public void setProperties(Properties properties) {

    }
}

2、配置SqlSessionFactory

package com.cjs.boot.config;

import com.cjs.boot.interceptor.SqlStatementInterceptor;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import javax.annotation.Resource;
import javax.sql.DataSource;

@Configuration
public class MyBatisConfig {

    @Resource
    private DataSource dataSource;

    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);
        sqlSessionFactoryBean.setPlugins(new Interceptor[]{new SqlStatementInterceptor()});
        PathMatchingResourcePatternResolver pathMatchingResourcePatternResolver = new PathMatchingResourcePatternResolver();
        sqlSessionFactoryBean.setMapperLocations(pathMatchingResourcePatternResolver.getResources("classpath:mapper/*Mapper.xml"));
        sqlSessionFactoryBean.setTypeAliasesPackage("com.cjs.boot.domain.entity");
        return sqlSessionFactoryBean.getObject();
    }

}

3、執行效果

2018-05-09 13:53:55.589 DEBUG 10988 --- [nio-8080-exec-2] c.c.b.m.C.selectByMerchantId             : ==>  Preparing: SELECT id, merchant_id, coupon_name, coupon_type, par_value, quantity, release_start_time, release_end_time, limit_type, limit_num, remark, create_time, update_time, yn FROM coupon_info WHERE merchant_id = ? 
2018-05-09 13:53:55.605 DEBUG 10988 --- [nio-8080-exec-2] c.c.b.m.C.selectByMerchantId             : ==> Parameters: 10009(Integer)
2018-05-09 13:53:55.619 DEBUG 10988 --- [nio-8080-exec-2] c.c.b.m.C.selectByMerchantId             : <==      Total: 0
2018-05-09 13:53:55.620  INFO 10988 --- [nio-8080-exec-2] c.c.b.i.SqlStatementInterceptor          : 執行SQL: [SELECT id, merchant_id, coupon_name, coupon_type, par_value, quantity, release_start_time, release_end_time, limit_type, limit_num, remark, create_time, update_time, yn FROM coupon_info WHERE merchant_id = ?]花費15ms

4、補充

4.1、@Signature註解的那幾個引數該怎麼寫

前面文件中說了，可以攔截那四個介面。本例中，我只想攔截查詢的SQL，所以我選擇攔截StatementHandler的query方法

package org.apache.ibatis.executor.statement;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;
import org.apache.ibatis.cursor.Cursor;
import org.apache.ibatis.executor.parameter.ParameterHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.session.ResultHandler;

public interface StatementHandler {
    Statement prepare(Connection var1, Integer var2) throws SQLException;

    void parameterize(Statement var1) throws SQLException;

    void batch(Statement var1) throws SQLException;

    int update(Statement var1) throws SQLException;

    <E> List<E> query(Statement var1, ResultHandler var2) throws SQLException;

    <E> Cursor<E> queryCursor(Statement var1) throws SQLException;

    BoundSql getBoundSql();

    ParameterHandler getParameterHandler();
}

所以，@Signature註解中，type表示攔截的介面，method表示介面中的方法，而引數就是該方法的引數

4.2、截圖