用MyBatis拦截器记录SQL执行时间

1、在项目的applicationContext-dao.xml 文件中增加一个plugins:sqlStatementInterceptor

<bean id="dao-sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="mapperLocations">
            <list>
                <value>classpath:com/test/mapper/*.xml</value>
                <value>classpath:com/test/mapper/extend/*.xml</value>
            </list>
        </property>
        <property name="plugins">
            <array>
                <bean id="sqlStatementInterceptor" class="com.test.SqlStatementInterceptor"/>
            </array>
        </property>
</bean>

2、编写sqlStatementInterceptor的实现代码

package com.test;

import java.util.Properties;

import org.apache.ibatis.cache.CacheKey;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 数据库操作性能拦截器,记录耗时
 */
@Intercepts(value = {
        @Signature(type = Executor.class, method = "update", args = { MappedStatement.class, Object.class }),
        @Signature(type = Executor.class, method = "query", args = { MappedStatement.class, Object.class,
                RowBounds.class, ResultHandler.class, CacheKey.class, BoundSql.class }),
        @Signature(type = Executor.class, method = "query", args = { MappedStatement.class, Object.class,
                RowBounds.class, ResultHandler.class }) })
public class SqlStatementInterceptor implements Interceptor
{
    private static Logger logger = LoggerFactory.getLogger(SqlStatementInterceptor.class);

    private Properties properties;

    @Override
    public Object intercept(Invocation arg0) throws Throwable
    {
        MappedStatement mappedStatement = (MappedStatement) arg0.getArgs()[0];
        String sqlId = mappedStatement.getId();
        Object returnValue;

        long start = System.currentTimeMillis();
        returnValue = arg0.proceed();
        long end = System.currentTimeMillis();
        long time = end - start;

        StringBuilder str = new StringBuilder(100);
        str.append(sqlId);
        str.append(": ");
        str.append("cost time ");
        str.append(time);
        str.append(" ms.");
        String sqlInfo = str.toString();
        logger.debug(sqlInfo);

        return returnValue;
    }

    @Override
    public Object plugin(Object arg0)
    {
        return Plugin.wrap(arg0, this);
    }

    @Override
    public void setProperties(Properties arg0)
    {
        this.properties = arg0;
    }
}

3、对sqlStatementInterceptor.java类里面的输出级别（上面代码块是debug级别），进行相应的logback.xml设置（只需修改文件内的level标签）

4、启动项目，从log文件中可看到日志打印

[http-8080-5] DEBUG [Caller+0 at com.test.SqlStatementInterceptor.intercept(SqlStatementInterceptor.java:49) ] - com.test.testMapper.selectByExample: cost time 1 ms.