myBatis系列之一：搭建开发环境

一.工程结构

二.在类路径下创建mybatis的配置文件Configuration.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>
	<typeAliases><!-- 别名 -->
		<typeAlias alias="User" type="com.bijian.study.model.User" />
	</typeAliases>
	
	<environments default="development">
	  <environment id="development">
		<transactionManager type="JDBC"/>
		<dataSource type="POOLED"><!-- 数据源 -->
			<property name="driver" value="com.mysql.jdbc.Driver" />
			<property name="url" value="jdbc:mysql://10.60.222.65:3306/test" />
			<property name="username" value="test" />
			<property name="password" value="test" />
		</dataSource>
	  </environment>
	</environments>
	
	<mappers><!-- ORM映射文件 -->
		<mapper resource="com/bijian/study/model/User.xml" />
	</mappers>
</configuration>

 

三.执行创建数据库和表的sql

-- Create the database named 'hbatis'.
-- It's OK to use `, not OK to use ' or " surrounding the database name to prevent it from being interpreted as a keyword if possible.
CREATE DATABASE IF NOT EXISTS `hbatis`
DEFAULT CHARACTER SET = `UTF8`;

-- Create a table named 'User'
CREATE TABLE `user` (
	`id` int(11) NOT NULL AUTO_INCREMENT,
	`name` varchar(50) DEFAULT NULL,
	`age` int(11) DEFAULT NULL,
	`address` varchar(200) DEFAULT NULL,
	PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

-- Insert a test record
Insert INTO `user` VALUES ('1', 'bijian', '120', 'hangzhou,westlake');

-- drop table
drop table `user`;

 

四.User类

package com.bijian.study.model;

public class User {
    
    private int id;
    private String name;
    private int age;
    private String address;
    
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    // 如果有带参数的构造器，编译器不会自动生成无参构造器。当查询需要返回对象时，ORM框架用反射来调用对象的无参构造函数，导致异常：java.lang.NoSuchMethodException: com.bijian.study.model.User.<init>()
    // 这时需要明确写出：
    public User() {
    }

    public User(int id, String address) {
        this.id = id;
        this.address = address;
    }

    public User(String name, int age, String address) {
        this.name = name;
        this.age = age;
        this.address = address;
    }
}

        User.java对应的User.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.bijian.study.model.UserMapper">
	<select id="getUserById" parameterType="int" resultType="User">
		select * from `user` where id = #{id}
	</select>
</mapper>

 

五.测试类

package com.bijian.study.test;

import java.io.IOException;
import java.io.Reader;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.BeforeClass;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.bijian.study.model.User;

public class MyBatisBasicTest {

    private static final Logger log = LoggerFactory.getLogger(MyBatisBasicTest.class);
    private static SqlSessionFactory sqlSessionFactory;

    private static Reader reader;

    @BeforeClass
    public static void initial() {
        try {
            reader = Resources.getResourceAsReader("Configuration.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (IOException e) {
            log.error("Error thrown while reading the configuration: {}", e);
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    log.error("Error thrown while closing the reader: {}", e);
                }
            }
        }
    }

    @Test
    public void queryTest() {
        SqlSession session = sqlSessionFactory.openSession();
        User user = (User) session.selectOne("com.bijian.study.model.UserMapper.getUserById", 1);
        log.info("{}: {}", user.getName(), user.getAddress());
    }
}

        运行单元测试结果：

00:28:18.710 [main] INFO  com.bijian.study.test.MyBatisBasicTest - bijian: hangzhou,westlake

 

文章来源：http://czj4451.iteye.com/blog/1976365