MyBatis入门案例

package com.mybatis.entity;

public class User {
private Long userId;
private String userName;
private Integer userAge;
private String 	userAddress;
private Type type;
public Long getUserId() {
return userId;
}
public void setUserId(Long userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public Integer getUserAge() {
return userAge;
}
public void setUserAge(Integer userAge) {
this.userAge = userAge;
}
public String getUserAddress() {
return userAddress;
}
public void setUserAddress(String userAddress) {
this.userAddress = userAddress;
}
public Type getType() {
return type;
}
public void setType(Type type) {
this.type = type;
}

@Override
public String toString() {
return "User [userId=" + userId + ", userName=" + userName
+ ", userAge=" + userAge + ", userAddress=" + userAddress
+ ", type=" + type + "]";
}

}

package com.mybatis.entity;

import java.util.HashSet;
import java.util.Set;

public class Type {

private Long typeId;
private String typeName;
private Set<User> users = new HashSet<User>();

public Long getTypeId() {
return typeId;
}
public void setTypeId(Long typeId) {
this.typeId = typeId;
}
public String getTypeName() {
return typeName;
}
public void setTypeName(String typeName) {
this.typeName = typeName;
}
public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
@Override
public String toString() {
return "Type [typeId=" + typeId + ", typeName=" + typeName + ", users="
+ users + "]";
}

}

<?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.mybatis.dao.UserMapper">

<!-- 定义用户集合对象 -->
<resultMap type="user" id="userMap">
<id column="id"  property="userId"/>
<result column="userName" property="userName"/>
<result column="userAge" property="userAge"/>
<result column="userAddress" property="userAddress"/>
<!-- 配置多对一的关联 -->
<association property="type" column="typeId" javaType="type"  select="selectTypeInfoByTypeId"/>
</resultMap>

<select id="selectAllUsers" resultMap="userMap">
select * from User
</select>

<select id="selectTypeInfoByTypeId" resultType="type">
select * from type where typeId=#{typeId}
</select>

<select id="selectUserByUserId" parameterType="user" resultMap="userMap">
<!-- 如果查询语句中只有一个参数可以随便写参数名称 -->
select * from user where 1=1
<if test="userName!=null">
AND userName=#{userName}
</if>
</select>

<insert id="addUserInfo">
<!-- 如果语句中存在多个参数，参数名称必须和属性名称一致 -->
insert into user values(#{userId},#{userName},#{userAge},#{userAddress},#{type.typeId})
</insert>

<update id="updateUserInfo">
update User set
userName=#{userName},
userAge=#{userAge},
userAddress=#{userAddress},
typeId=#{type.typeId}
where id=#{userId}
</update>

<delete id="deleteUserByUserId">
delete from user where id = #{id}
</delete>
</mapper>

<?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="typeInfo">

<!-- 定义类型信息对象 -->
<resultMap type="type" id="typeMap">
<id column="typeId" property="typeId" />
<result column="typeName" property="typeName"/>
<!-- 一对多 -->
<collection property="users" column="typeId" ofType="user" select="selectUserByTypeId" />
</resultMap>

<select id="selectUserByTypeId" resultMap="com.mybatis.dao.UserMapper.userMap">
select * from User where typeId = #{typeId}
</select>

<select id="selectTypeInfoByTypeId" resultMap="typeMap">
select * from type where typeId=#{typeId}
</select>
</mapper>

<?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>
<!-- 给个实体取别名 -->
<typeAliases>
<typeAlias type="com.mybatis.entity.User" alias="user"/>
<typeAlias type="com.mybatis.entity.Type" alias="type"/>
</typeAliases>

<!-- 配置数据源
注意：environment id属性值必须为和default的值相同
-->
<environments default="dev">
<environment id="dev">
<transactionManager type="JDBC" />
<dataSource type="UNPOOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</dataSource>
</environment>
</environments>

<!-- 导入Mybatis映射文件 -->
<mappers>
<mapper resource="config/UserMapper.xml"/>
<mapper resource="config/TypeMapper.xml"/>
</mappers>
</configuration>

package com.mybatis.dao;

import com.mybatis.entity.User;

public interface UserMapper {
int addUserInfo(User user);
}

package com.mybatis.test;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

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.Test;

import com.mybatis.dao.UserMapper;
import com.mybatis.entity.Type;
import com.mybatis.entity.User;

public class TestMyBatis {

private static SqlSessionFactory sqlSessionFactory;

static {

try {
// 把mybatis-config.xml文件转换为字符流对象
Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

private SqlSession getSession() {
return sqlSessionFactory.openSession();
}

@Test
public void test() {
System.out.println(sqlSessionFactory);
}

@Test
public void testSelectAll() {
List<Object> objects = (List<Object>) getSession().selectList("selectAllUsers");
System.out.println(objects);
}

@Test
public void testSelectUser() {
User userInfo = new User();
userInfo.setUserName("赞赏");
List<Object> objects = (List<Object>) getSession().selectList("selectUserByUserId",userInfo);
System.out.println(objects);
}

@Test
public void insertUserInfo() {

SqlSession session = getSession();
// 创建用户对象
User user = new User();
user.setUserId(40002L);
user.setUserName("展示那1");
user.setUserAge(40);
user.setUserAddress("重庆1");
Type type = new Type();
type.setTypeId(1003L);
user.setType(type);
session.insert("addUserInfo",user);
session.commit();
session.close();
}

@Test
public void updateUserInfo() {

SqlSession session = getSession();
// 创建用户对象
User user = new User();
user.setUserId(40002L);
user.setUserName("赞赏");
user.setUserAge(40);
user.setUserAddress("重庆1");
Type type = new Type();
type.setTypeId(1003L);
user.setType(type);
session.update("updateUserInfo",user);
session.commit();
session.close();
}

@Test
public void deletetUser() {
SqlSession session = getSession();
int row = session.delete("deleteUserByUserId",40001);
session.commit();
session.close();

System.out.println(row>0?"成功":"失败");
}

@Test // 测试一对多的管理查询
public void selectTypeByTypeId() {
SqlSession session = getSession();
Type type = session.selectOne("typeInfo.selectTypeInfoByTypeId", 1003);
System.out.println(type);
}

@Test // 开发中常用方法
public void testAddUserInfo() {
SqlSession session = getSession();
UserMapper userMapper = session.getMapper(UserMapper.class);
User user = new User();
user.setUserId(40005L);
user.setUserName("fdsfds");
user.setUserAge(40);
user.setUserAddress("hgfgd");
Type type = new Type();
type.setTypeId(1003L);
user.setType(type);
System.out.println(userMapper.addUserInfo(user));
session.commit();
session.close();
}
}