MyBatis的配置以及crud操作

1.加入日志配置文件Log4j.properties，放在src下（需要导入log4j-1.2.17.jar）

### \u8BBE\u7F6E### info error debug
log4j.rootLogger = debug,stdout,D,E

### \u8F93\u51FA\u4FE1\u606F\u5230\u63A7\u5236\u62AC ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

2.SqlMapConfig.xml，配置mybatis的运行环境，数据源，事物等，放在src下。(需要导入mybatis-3.2.8.jar)

<?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" />
<property name="url" value="jdbc:mysql:///house" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/zucc/dao/UserMapper.xml" />
</mappers>

</configuration><span style="font-size:18px;">
</span>

3.创建数据库

4.编写User.java实体类

package com.zucc.model;

public class User {

private int id;
private String username;
private String password;
private String phone;

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;
}

public String getPhone() {
return phone;
}

public void setPhone(String phone) {
this.phone = phone;
}

@Override
public String toString() {
return "User [id=" + id + ", username=" + username + ", password="
+ password + ", phone=" + phone + "]";
}

}

5.编写User.xml（根据用户id(主键)查询用户信息）

<?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">

<!--namspace命名空间，作用是对sql进行分类管理，sql隔离  -->

<mapper namespace="UserMapper">

<!-- 在映射文件中可以配置很多sql语句 -->
<!-- 通过select标签执行数据库查询，id是标识映射文件中的sql，parameterType是指定输入参数的类型，这里是Int -->
<!-- #{}相当于jdbc中的占位符，名字随意 -->
<!-- resultType是指定sql输出结果所映射的java对象类型，select指定resultType表示将单条记录映射成java对象 -->

<select id="findUserById" parameterType="int" resultType="com.zucc.model.User">
select * from User where id = #{id}
</select>

</mapper>

6.需要在sqlMapConfig.xml中配置User.xml

<span style="white-space:pre">	</span><mappers>
<mapper resource="com/zucc/dao/UserMapper.xml" />
</mappers>

7.在数据库中插入一条信息

8.程序测试(可能需要导入junit-4.11.jar和hamcrest-core-1.3.jar)

package com.zucc.Test;

import java.io.IOException;
import java.io.InputStream;

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.zucc.model.User;

public class UserTest {

@Test
public void find() throws IOException{
//mybatis配置文件
String resource = "SqlMapConfig.xml";
//得到配置文件流
InputStream is = Resources.getResourceAsStream(resource);
//创建会话工厂，传入mybatis的配置文件信息
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
//通过工厂得到SqlSession
SqlSession sqlSession = sqlSessionFactory.openSession();
//通过SqlSession操作数据库
//第一个参数：映射文件中statement的id,等于"namespace.statment的id"
//第二个参数：指定和映射文件中所匹配的parameterType类型的参数
//SqlSession.selectOne结果是与映射文件中所匹配的resultType类型的对象
User user = sqlSession.selectOne("UserMapper.findUserById", 1);
System.out.println(user.toString());
sqlSession.close();
}

}

9.编写User.xml，添加用户信息

<span style="white-space:pre">	</span><!-- 添加用户
<span style="white-space:pre">		</span>#{}中指定pojo的属性名，接收到pojo对象的属性值，mybatis通过ognl获取对象的属性值
<span style="white-space:pre">	</span> -->
<span style="white-space:pre">	</span><insert id="addUser" parameterType="User">
<span style="white-space:pre">		</span>insert into user (username,password,telephone) values (#{username},#{password},#{phone})
<span style="white-space:pre">	</span></insert>

<span style="white-space:pre">	</span>@Test
<span style="white-space:pre">	</span>public void add() throws IOException {
<span style="white-space:pre">		</span>User user = new User();
<span style="white-space:pre">		</span>user.setUsername("rqq");
<span style="white-space:pre">		</span>user.setPassword("123");
<span style="white-space:pre">		</span>user.setPhone("15164897856");
<span style="white-space:pre">		</span>sqlSession.insert("UserMapper.addUser", user);
<span style="white-space:pre">		</span>sqlSession.commit();
<span style="white-space:pre">	</span>}

10.编写User.xml，根据用户id(主键)修改用户信息

<span>	</span><update id="updateUser" parameterType="User">
update user <set>
<if test="username != null">
username = #{username},
</if>
<if test="password != null">
password = #{password},
</if>
<if test="phone != null">
telephone = #{phone},
</if>
</set>
where uid=#{id}
</update>

<span style="white-space:pre">	</span>@Test
<span style="white-space:pre">	</span>public void update() throws IOException {
<span style="white-space:pre">		</span>User user = new User();
<span style="white-space:pre">		</span>user.setUsername("rqq");
<span style="white-space:pre">		</span>user.setPassword("111");
<span style="white-space:pre">		</span>user.setPhone("1888888888");
<span style="white-space:pre">		</span>user.setId(6);
//<span style="white-space:pre">		</span>userMapper.updateUser(user);
<span style="white-space:pre">		</span>sqlSession.update("UserMapper.updateUser", user);
<span style="white-space:pre">		</span>sqlSession.commit();
<span style="white-space:pre">	</span>}

11.编写User.xml，根据用户id(主键)删除用户信息

<span>	</span><delete id="deleteUser" parameterType="int">
<span style="white-space:pre">		</span>delete from user where uid = #{id}
<span style="white-space:pre">	</span></delete>

<span>	</span>@Test
<span style="white-space:pre">	</span>public void delete() throws IOException {
//<span style="white-space:pre">		</span>userMapper.deleteUser(6);
<span style="white-space:pre">		</span>sqlSession.delete("UserMapper.deleteUser", 6);
<span style="white-space:pre">		</span>sqlSession.commit();
<span style="white-space:pre">	</span>}