log4j.xml mysql_log4j2打印Mybatis执行的SQL语句及SQL语句的执行时间

### 一、首先如需使用log4j2，得引入maven依赖 ###

org.apache.logging.log4j

log4j-api

${log4j2.version}

org.apache.logging.log4j

log4j-core

${log4j2.version}

org.apache.logging.log4j

log4j-web

${log4j2.version}

注：本人使用的是2.7版本的log4j2

### 二、然后在项目的classpath下编写log4j2.xml ###

log4j2在启动的时候会默认加载名为log4j2.xml的配置文件

D:/log4j2/mybatis/genertor/logs/

error

fileName="${LOG_HOME}/${ERROR_LOG_FILE_NAME}.log"

filePattern="${LOG_HOME}/${ERROR_LOG_FILE_NAME}.log.%d{yyyy-MM-dd}.gz">

pattern="%d %-5p (%F:%L) - %m%n"/>

### 三、在web.xml中配置log4j2的加载启动 ###

org.apache.logging.log4j.web.Log4jServletContextListener

log4jServletFilter

org.apache.logging.log4j.web.Log4jServletFilter

log4jServletFilter

/*

REQUEST

FORWARD

INCLUDE

ERROR

注：加上上述配置后，就能在项目启动是加载log4j2

### 四、在Mybatis的配置文件中，加入上述配置 ###

/p>

PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-config.dtd">

注：settings配置完毕后，即可实现SQL语句的打印！控制台打印如下结果：

2017-10-23 16:38:01,021 DEBUG (BaseJdbcLogger.java:145) - ==> Preparing: SELECT count(*) FROM t_user

2017-10-23 16:38:01,056 DEBUG (BaseJdbcLogger.java:145) - ==> Parameters:

2017-10-23 16:38:01,084 DEBUG (BaseJdbcLogger.java:145) - <== Total: 1

### 五、实现Mybatis官方提供的拦截器，用于记录SQL语句的执行时间 ###

package com.stu.interceptor;

import java.sql.Statement;

import java.util.Properties;

import org.apache.ibatis.executor.statement.StatementHandler;

import org.apache.ibatis.plugin.Interceptor;

import org.apache.ibatis.plugin.Intercepts;

import org.apache.ibatis.plugin.Invocation;

import org.apache.ibatis.plugin.Plugin;

import org.apache.ibatis.plugin.Signature;

import org.apache.ibatis.session.ResultHandler;

/**

* Sql执行时间记录拦截器

*/

@Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),

@Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),

@Signature(type = StatementHandler.class, method = "batch", args = { Statement.class })})

public class SqlCostInterceptor implements Interceptor {

@Override

public Object intercept(Invocation invocation) throws Throwable {

long startTime = System.currentTimeMillis();

try {

return invocation.proceed();

} finally {

long endTime = System.currentTimeMillis();

long sqlCost = endTime - startTime;

System.out.println("执行耗时 : [" + sqlCost + "ms ] ");

}

}

@Override

public Object plugin(Object target) {

return Plugin.wrap(target, this);

}

@Override

public void setProperties(Properties properties) {

}

}

注：Interceptor接口是Mybatis官方提供的拦截接口，创建一个类实现该接口并重写其三个方法并将该类配置在Mybatis的配置文件中，即可拦截SQL语句的执行过程

### 六、将手动编写的拦截器配置在Mybatis配置文件中： ###

/p>

PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

"http://mybatis.org/dtd/mybatis-3-config.dtd">

### 七、测试SQL的控制台打印结果 ###

2017-10-23 16:38:01,091 DEBUG (BaseJdbcLogger.java:145) - ==> Preparing: select id, username, password, state, isdel, add_time, money, left_money from t_user limit ?,?

2017-10-23 16:38:01,093 DEBUG (BaseJdbcLogger.java:145) - ==> Parameters: 0(Integer), 15(Integer)

2017-10-23 16:38:01,128 DEBUG (BaseJdbcLogger.java:145) - <== Total: 15

执行耗时 : [36ms ]