MyBatis 插件测试

我这里只是拿了当前的sql语句，可以对它进行操作，然后可以将操作过后的sql语句反射回BoundSql。
就可以做分页或者其他功能，就不需要在映射文件写了。

通过
http://blog.csdn.net/hfmbook/article/details/41985853
这个大佬写的来学习的，写的很详细的
以下是代码

TestPlugin.java

package com.hgf.ssm.util;

import org.apache.ibatis.executor.statement.RoutingStatementHandler;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.plugin.*;

import java.lang.reflect.Field;
import java.sql.Connection;
import java.util.Properties;

/**
 * Created by hasee on 2017/1/22.
 * 测试MyBatis插件，功能其实感觉就是过滤器
 */
@Intercepts({ @Signature(type = StatementHandler.class, method = "prepare", args = { Connection.class }) })
public class TestPlugin implements Interceptor {

    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        System.out.println("intercept");
        //获取RoutingStatementHandler对象
        RoutingStatementHandler statementHandler = (RoutingStatementHandler)invocation.getTarget();

        //通过反射得到delegate的filed类
        Field field = statementHandler.getClass().getDeclaredField("delegate");
        Object value = null;
        //判断field是否需要进行java语言访问检查，参考 https://my.oschina.net/nixi0608/blog/724343
        if (field.isAccessible()) {
            value = field.get(statementHandler);
        } else {
            field.setAccessible(true);
            value = field.get(statementHandler);
            field.setAccessible(false);
        }
        StatementHandler delegate = (StatementHandler)value;
        BoundSql boundSql = delegate.getBoundSql();
        //获取当前sql语句
       String sql =  boundSql.getSql();
        System.out.println(sql);
        return  invocation.proceed();
    }

    @Override
    public Object plugin(Object o) {
        System.out.println("plugin");
        if (o instanceof StatementHandler) {
            return Plugin.wrap(o, this);
        } else {
            return o;
        }

    }

    @Override
    public void setProperties(Properties properties) {

    }
}

spring-mybatis.xml

<!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
        <property name="dataSource" ref="dataSource" />
        <!-- 自动扫描mapping.xml文件 -->
        <property name="mapperLocations" value="classpath*:com/hgf/ssm/dao/mapper/*.xml"></property>
        <property name="typeAliasesPackage" value="com.hgf.ssm.dao.po" />
        <property name="configLocation" value="classpath:mybatis-configuration.xml" />
    </bean>

mybatis-configuration.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN"
        "http://ibatis.apache.org/dtd/ibatis-3-config.dtd">

<!-- MyBatis数据持久层配置文件 -->
<configuration>





    <!-- 插件 -->
    <plugins>
        <!-- StatementHandler插件 -->
        <plugin interceptor="com.hgf.ssm.util.TestPlugin">
            <property name="sqlid" value=".*Page" />
        </plugin>


    </plugins>

</configuration>