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>