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