mybatis：@Intercepts小例子（一）

这只是一个纯碎的mybatis的只针对@Intercepts应用的小列子，没有和spring做集成。

1.工作目录

2.数据库mysql，建立一个数据库表、实体对象User、UserMapper.java、UserMapper.xml省略。

使用mybatis自动代码生成工具生成：mybatis-generator-core-1.3.2。（此处略）

3.拦截器MyInterceptor.java

package com.tiantian.mybatis.interceptor;

import java.sql.Connection;
import java.util.Properties;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.MappedStatement;
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;
import org.apache.ibatis.session.RowBounds;
@Intercepts( {
    @Signature(method = "query", type = Executor.class, args = {
           MappedStatement.class, Object.class, RowBounds.class,
           ResultHandler.class }),
    @Signature(method = "prepare", type = StatementHandler.class, args = { Connection.class }) })
public class MyInterceptor implements Interceptor {
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        Object result = invocation.proceed();
        System.out.println("Invocation.proceed()");
        return result;
    }

    @Override
    public Object plugin(Object target) {
        // TODO Auto-generated method stub
        return Plugin.wrap(target, this);
    }

    @Override
    public void setProperties(Properties properties) {
        String prop1 = properties.getProperty("prop1");
        String prop2 = properties.getProperty("prop2");
        System.out.println(prop1 + "------" + prop2);
    }
}

4.配置文件mybatis-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <properties resource="jdbc.properties"></properties>
    <typeAliases>
       <package name="com.tiantian.mybatis.model"/>
    </typeAliases>
    <plugins>
       <plugin interceptor="com.tiantian.mybatis.interceptor.MyInterceptor">
           <property name="prop1" value="prop1"/>
           <property name="prop2" value="prop2"/>
       </plugin>
    </plugins>
    <environments default="development">
       <environment id="development">
           <transactionManager type="JDBC" />
           <dataSource type="POOLED">
              <property name="driver" value="${driver}" />
              <property name="url" value="${url}" />
              <property name="username" value="${username}" />
              <property name="password" value="${password}" />
           </dataSource>
       </environment>
    </environments>
    <mappers>
       <mapper resource="com/tiantian/mybatis/mapper/UserMapper.xml"/>
    </mappers>
</configuration>

5.配置文件jdbc.properties

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/database_yxl
username=root
password=123456
#定义初始连接数
initialSize=0
#定义最大连接数
maxActive=20
#定义最大空闲
maxIdle=20
#定义最小空闲
minIdle=1
#定义最长等待时间
maxWait=60000

6.测试文件TestMyBatis.java

package com.tiantian.mybatis.service;

import org.apache.ibatis.session.SqlSession;
import com.tiantian.base.MyBatisUtil;
import com.tiantian.mybatis.domain.User;

public class TestMyBatis {
    public static void main(String[] args) {
        SqlSession session = MyBatisUtil.getSqlSession();
        /**
         * 映射sql的标识字符串，
         * com.tiantian.mybatis.mapper.userMapper是userMapper.xml文件中mapper标签的namespace属性的值，
         * selectByPrimaryKey是select标签的id属性值，通过select标签的id属性值就可以找到要执行的SQL
         */
        String statement = "com.tiantian.mybatis.mapper.UserMapper.selectByPrimaryKey";//映射sql的标识字符串
        //执行查询返回一个唯一user对象的sql
        User user = session.selectOne(statement, 1);
        System.out.println(user);
    }
}

输出结果：

prop1------prop2
Invocation.proceed()
Invocation.proceed()
[id:1;username:测试;password:sfasgfaf]

7.工具类MyBatisUtil.java

package com.tiantian.base;

import java.io.InputStream;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class MyBatisUtil {
    public static SqlSessionFactory getSqlSessionFactory() {
        String resource = "mybatis-config.xml";
        // 使用类加载器加载mybatis的配置文件（它也加载关联的映射文件）
        InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream(resource);
        // 构建sqlSession的工厂
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
        return sessionFactory;
    }

    public static SqlSession getSqlSession() {
        return getSqlSessionFactory().openSession();
    }

    public static SqlSession getSqlSession(boolean isAutoCommit) {
        return getSqlSessionFactory().openSession(isAutoCommit);
    }
}

参考文章

http://www.tuicool.com/articles/7bYjUn

http://www.cnblogs.com/xdp-gacl/p/4262895.html

http://www.mybatis.org/mybatis-3/zh/index.html