mybatis入门---helloworld程序开发步骤

1.新建一个Java Project,命名为mybatis-01-helloworld

2.工程名右键，新建一个Source Folder，名为lib

3.添加Jar包，将 mybatis-3.3.1.jar和mysql-connector-java-5.03-bin.jar包复制到lib目录下，选中两个jar包，

  右键Build Path-->Add to build path,会发现工程下面多了一个Reference Liberies目录，下面放着这两个jar包，

  表示java已经可以识别这两个jar包

ps:mybatis-3.3.1.jar---添加mybatis支持

    mysql-connector-java-5.03-bin.jar---添加sql支持，因为mybatis是半自动的，sql语句全部自己手写

      而不是像hibernate一样，完全自动生成。(hibernate是全自动的)

4.在src目录下新建mybatis的配置文件，命名为mybatis.xml(内容可以上网拷贝)

<pre name="code" class="html"><?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>

<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="org/mybatis/example/BologMapper.xml" /></mappers></configuration>

然后根据自己的项目，进行相应的更改

<?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><environments default="development"><environment id="development"><transactionManager type="JDBC" /><dataSource type="POOLED">        <property name="driver" value="com.mysql.jdbc.Driver" /> //自己建立的数据库连接名称<property name="url" value="jdbc:mysql://localhost/test" /> //数据库名称<property name="username" value="root" /> //数据库的用户名<property name="password" value="root" /> //数据库的密码</dataSource></environment></environments><mappers><mapper resource="com/etc/mapper/UserMapper.xml" /></mappers></configuration>

5.在src目录下新建com.etc.mapper包，在包下新建UserMapper.xml文件

<?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.etc.mapper.UserMapper"><select id="findById" resultType="com.etc.mapper.User">select user_id id ,user_name username ,user_pass password from t_user where user_id = 1</select></mapper>

6.在com.etc.mapper包下新建User.java

package com.etc.mapper;public class User {private int id;private String username;private String password;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}@Overridepublic String toString() {return "User [id=" + id + ", username=" + username + ", password="+ password + "]";}}

7.在com.etc.mapper包下新建UserMapper.java文件

package com.etc.mapper;public interface UserMapper { User findById();}

8.右键工程名，新建SourceFolder文件夹，新建UserMapperTest.java

package com.etc.mapper;import java.io.InputStream;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Test;public class UserMapperTest {@Testpublic void test() {InputStream config = this.getClass().getResourceAsStream("/mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(config);SqlSession session = factory.openSession();UserMapper userMapper = session.getMapper(UserMapper.class);User user = userMapper.findById();System.out.println(user);}}

9.右键运行，JUnit Test，控制台返回结果如下：

User [id=1, username=zoe, password=123]

10.目录架构图如下：