Mybatis拦截器实现SQL性能监控

　　Mybatis拦截器只能拦截四类对象，分别为：Executor、ParameterHandler、StatementHandler、ResultSetHandler，而SQL数据库的操作都是从Executor开始，因此要记录Mybatis数据库操作的耗时，需要拦截Executor类，代码实现如下：

/**

 * 数据库操作性能拦截器,记录耗时

 * @Intercepts定义Signature数组,因此可以拦截多个,但是只能拦截类型为：

 *         Executor

 *         ParameterHandler

 *         StatementHandler

 *         ResultSetHandler

 * */

@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 TimerInterceptor implements Interceptor {

    private static final Logger logger = Logger.getLogger(TimerInterceptor.class);

    /**

     * 实现拦截的地方

     * */

    @Override

    public Object intercept(Invocation invocation) throws Throwable {

        Object target = invocation.getTarget();

        Object result = null;

        if (target instanceof Executor) {

            long start = System.currentTimeMillis();

            Method method = invocation.getMethod();

            /**执行方法*/

            result = invocation.proceed();

            long end = System.currentTimeMillis();

            logger.info("[TimerInterceptor] execute [" + method.getName() + "] cost [" + (end - start) + "] ms");

        }

        return result;

    }

    /**

     * Plugin.wrap生成拦截代理对象

     * */

    @Override

    public Object plugin(Object target) {

        return Plugin.wrap(target, this);

    }

    @Override

    public void setProperties(Properties properties) {

    }

}

　　完成上面的拦截后，需要将该类在Mybatis配置文件中声明，如下：

<plugins><!-- SQL性能拦截器 --><plugin interceptor="com.quar.interceptor.TimerInterceptor" /></plugins>

来源：http://www.cnblogs.com/hanfight/p/4752782.html

来自为知笔记(Wiz)

Mybatis拦截器实现SQL性能监控的相关教程结束。