03.Mybatis框架的第一次使用
1、Po类（数据库表对应的java模型）
UserPo.java
package com.company.project.model;
/**
* @author God_86
*
*/
public class UserPo {
private long userId;
private String userName;
private long phoneNum;
private String password;
private String name;
private String sex;
private String shippingAddress;
public UserPo() {
super();
this.userId = 0;
this.userName = "";
this.phoneNum = 0;
this.password = "";
this.name = "";
this.sex = "";
this.shippingAddress = "";
}
public String getUserName() {
return userName;
}
public long getPhoneNum() {
return phoneNum;
}
public String getPassword() {
return password;
}
public String getName() {
return name;
}
public String getSex() {
return sex;
}
public String getShippingAddress() {
return shippingAddress;
}
public long getUserId() {
return userId;
}
public void setUserId(long userId) {
this.userId = userId;
}
public void setUserName(String userName) {
this.userName = userName;
}
public void setPhoneNum(long phoneNum) {
this.phoneNum = phoneNum;
}
public void setPassword(String password) {
this.password = password;
}
public void setName(String name) {
this.name = name;
}
public void setSex(String sex) {
this.sex = sex;
}
public void setShippingAddress(String shippingAddress) {
this.shippingAddress = shippingAddress;
}
@Override
public String toString() {
return "UserPo [userId=" + userId + ", userName=" + userName + ", phoneNum=" + phoneNum + ", password="
+ password + ", name=" + name + ", sex=" + sex + ", shippingAddress=" + shippingAddress + "]";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((name == null) ? 0 : name.hashCode());
result = prime * result + ((password == null) ? 0 : password.hashCode());
result = prime * result + (int) (phoneNum ^ (phoneNum >>> 32));
result = prime * result + ((sex == null) ? 0 : sex.hashCode());
result = prime * result + ((shippingAddress == null) ? 0 : shippingAddress.hashCode());
result = prime * result + (int) (userId ^ (userId >>> 32));
result = prime * result + ((userName == null) ? 0 : userName.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
UserPo other = (UserPo) obj;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
if (password == null) {
if (other.password != null)
return false;
} else if (!password.equals(other.password))
return false;
if (phoneNum != other.phoneNum)
return false;
if (sex == null) {
if (other.sex != null)
return false;
} else if (!sex.equals(other.sex))
return false;
if (shippingAddress == null) {
if (other.shippingAddress != null)
return false;
} else if (!shippingAddress.equals(other.shippingAddress))
return false;
if (userId != other.userId)
return false;
if (userName == null) {
if (other.userName != null)
return false;
} else if (!userName.equals(other.userName))
return false;
return true;
}
}
2、mapper接口类（数据库表操作的方法接口）
UserMapper.java
package com.company.project.mapper;
import java.util.List;
import org.apache.ibatis.annotations.Select;
import com.company.project.model.UserPo;
public interface UserMapper {
//插入方法
boolean insert(UserPo userPo);
//更新方法
boolean update(UserPo userPo);
//删除方法
boolean delete(long id);
//查询主键
UserPo findById(long id);
//查询所有
List<UserPo> findAll();
3、配置文件的编写（java Po 类与数据库表操作的对应关系）
UserMapper.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.company.project.mapper.UserMapper">
<!--
namespace：名称空间,指定为接口的全类名
id：唯一标识
resultType：返回值类型
#{id}：从传递过来的参数中取出id值
public UserPo findById(long id);
-->
<!-- 配置结果视图 -->
<resultMap type="userpo" id="baseResultSet">
<id column="id" property="userId"/>
<result column="user_name" property="userName" />
<result column="phone_num" property="phoneNum" />
<result column="password" property="password" />
<result column="name" property="name" />
<result column="sex" property="sex" />
<result column="shipping_address" property="shippingAddress" />
</resultMap>
<!-- 通过主键查询 -->
<select id="findById" resultMap="baseResultSet">
select id , user_name , phone_num , password , name ,sex,shipping_address from "USER"
where id=#{id}
<!--
<where>
<if test="id != null">id=#{id}</if>
<if test="user_name != null">user_name=#{user_name}</if>
</where>
-->
</select>
<!-- 查询所有 -->
<select id="findAll" resultMap="baseResultSet">
select id , user_name , phone_num , password , name ,sex,shipping_address from "USER"
</select>
<!-- 插入 -->
<insert id="insert" parameterType="UserPo" >
insert into "USER" values(
#{userId},
#{userName},
#{phoneNum},
#{password},
#{name},
#{sex},
#{shippingAddress}
)
</insert>
<!-- 更新 -->
<update id="update" parameterType="UserPo">
update "USER" set
user_name=#{userName},
phone_num=#{phoneNum},
password=#{password},
name=#{name},
sex=#{sex},
shipping_address=#{shippingAddress}
Where id = #{userId}
</update>
<!-- 删除 -->
<delete id="delete" parameterType="java.lang.Long">
delete "USER"
Where id = #{userId}
</delete>
</mapper>
4、更新主配文件
mybatis-config.xml 文件
<?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>
<!-- 导入数据库配置文件 -->
<properties resource="jdbc.properties"></properties>
<typeAliases>
<!-- 利用package标签可以直接把整个包的 Po类都导入，这块是导入与数据库表对应的java类-->
<package name="com.company.project.model"/>
</typeAliases>
<!-- 配置数据库信息 -->
<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>
<!-- 将我们写好的sql映射文件一定要注册到全局配置文件中 -->
<mappers>
<!-- 利用package标签可以直接把整个包的 xml配置文件都导入，这块是导入数据库表与java Po类对应的配置文件 -->
<package name="com.company.project.mapper" />
</mappers>
</configuration>
（1）在 < typeAliases >标签中，利用< package > 导入所有的model Po类
（2）在 < mappers >标签中，利用< package > 导入所有的 XXXMapper.xml配置文件。
注意：
- 接口类应该和对应的配置类同名，这样才可以自动配置，可以省去很多步骤
- 接口类XXXMapper.java应该和对应的配置类XXXMapper.xml应该写在同一个包下，这样可以自动配置。
- 但是为了防止臃肿，我们可以把配置类XXXMapper.xml文件写在conf下，创建一个与接口类XXXMapper.java同名的包，把XXXMapper.xml文件写在包下，这样看起来，他们两个文件就没有在同一目录下，但是编译以后，在build路径下，接口类XXXMapper.java编译生成的XXXMapper.class会和XXXMapper.xml编译生成的XXXMapper.xml在同一目录文件下，所以间接性的把两个文件放在了同一包下，实现了上述的要求。
5、测试
UserMapperTest.java
package com.company.project.daotest;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.company.project.mapper.UserMapper;
import com.company.project.model.UserPo;
import com.company.project.util.MyBatisUtil;
import junit.framework.TestCase;
public class UserMapperTest extends TestCase{
public void testFindById() {
Logger logger = LoggerFactory.getLogger("hello");
//获取会话
SqlSession session = MyBatisUtil.getSession();
try {
//获取接口的实现类对象
//会自动为接口创建一个代理对象，代理对象去执行增删改查
UserMapper mapper = session.getMapper(UserMapper.class);
UserPo userPo = mapper.findById(1000001l);
System.out.println(userPo);
logger.info(userPo.toString());
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
public void testFindAll() {
//获取会话
SqlSession session = MyBatisUtil.getSession();
try {
//获取接口的实现类对象
//会自动为接口创建一个代理对象，代理对象去执行增删改查
UserMapper mapper = session.getMapper(UserMapper.class);
List<UserPo> userPoList = mapper.findAll();
for(UserPo userPo : userPoList) {
System.out.println(userPo.toString());
}
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
public void testInsert() {
//获取会话
SqlSession session = MyBatisUtil.getSession();
try {
//获取接口的实现类对象
//会自动为接口创建一个代理对象，代理对象去执行增删改查
UserMapper mapper = session.getMapper(UserMapper.class);
UserPo userPo = new UserPo();
userPo.setUserId(1000003l);
userPo.setName("王五");
userPo.setPassword("123456");
userPo.setPhoneNum(15555555555l);
userPo.setSex("女");
userPo.setShippingAddress("陕西省");
userPo.setUserName("小仙女");
System.out.println(userPo.toString());
boolean flag = mapper.insert(userPo);
if(flag) {
session.commit();
System.out.println("插入成功");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
public void testUpdate() {
//获取会话
SqlSession session = MyBatisUtil.getSession();
try {
//获取接口的实现类对象
//会自动为接口创建一个代理对象，代理对象去执行增删改查
UserMapper mapper = session.getMapper(UserMapper.class);
UserPo userPo = new UserPo();
userPo.setUserId(1000003l);
userPo.setName("王五");
userPo.setPassword("123456");
userPo.setPhoneNum(15555555555l);
userPo.setSex("女");
userPo.setShippingAddress("重庆市");
userPo.setUserName("小美女");
System.out.println(userPo.toString());
boolean flag = mapper.update(userPo);
if(flag) {
session.commit();
System.out.println("更新成功");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
public void testDelete() {
//获取会话
SqlSession session = MyBatisUtil.getSession();
try {
//获取接口的实现类对象
//会自动为接口创建一个代理对象，代理对象去执行增删改查
UserMapper mapper = session.getMapper(UserMapper.class);
boolean flag = mapper.delete(1000003l);
if(flag) {
session.commit();
System.out.println("删除成功");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
}
}
注意：
在mybatis中，对数据库操作，除了查询以外，其他的操作都需要进行提交 session.commit();，否则不会对数据库生效。
