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基础环境
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- IDEA
<br/> - MAVEN
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工程目录
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mysql数据库
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Maven Pom
添加mybatis以及mysql的依赖包
<!--pom xml配置内容-->
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mu</groupId>
<artifactId>mybatis</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.29</version>
</dependency>
</dependencies>
<build>
<!--idea不会寻找src/main/java目录下的xml配置-->
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
<include>**/*.tld</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
<include>**/*.tld</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
</project>
创建各实体类以及mapper.xml文件
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- User.java
package com.mu.mybatis.domain;
/**
* Created by manunited1985 on 2017/11/23.
*/
public class User {
private Integer userId;
private String userName;
private String userPassword;
private String userEmail;
public User(Integer userId, String userName, String userPassword, String userEmail) {
this.userId = userId;
this.userName = userName;
this.userPassword = userPassword;
this.userEmail = userEmail;
}
public Integer getUserId() {
return userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getUserPassword() {
return userPassword;
}
public void setUserPassword(String userPassword) {
this.userPassword = userPassword;
}
public String getUserEmail() {
return userEmail;
}
public void setUserEmail(String userEmail) {
this.userEmail = userEmail;
}
@Override
public String toString() {
return "User [userId=" + userId + ", userName=" + userName
+ ", userPassword=" + userPassword + ", userEmail=" + userEmail
+ "]";
}
}
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- UserMapper.java
package com.mu.mybatis.mapper;
import com.mu.mybatis.domain.User;
/**
* Created by manunited1985 on 2017/11/24.
*/
public interface UserMapper {
public User selectUserById(Integer userId);
public List<User> selectUserAll();
public void insertUser(User user);
}
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- 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.mu.mybatis.mapper.UserMapper">
<!--设置domain类和数据库中表的字段一一对应,注意数据库字段和domain类中的字段名称不致,此处一定要!-->
<resultMap id="BaseResultMap" type="com.mu.mybatis.domain.User">
<id column="USER_ID" property="userId" jdbcType="INTEGER" />
<result column="USER_NAME" property="userName" jdbcType="CHAR" />
<result column="USER_PASSWORD" property="userPassword" jdbcType="CHAR" />
<result column="USER_EMAIL" property="userEmail" jdbcType="CHAR" />
</resultMap>
<!-- 查询单条记录 -->
<select id="selectUserById" parameterType="int" resultMap="BaseResultMap">
SELECT * FROM t_user WHERE USER_ID = #{userId}
</select>
<!-- 查询所有记录 -->
<select id="selectUserAll" resultMap="BaseResultMap">
SELECT * FROM t_user
</select>
<!-- 插入单条记录 -->
<insert id="insertUser" parameterType="com.mu.mybatis.domain.User">
insert into t_user (USER_ID,USER_NAME,USER_PASSWORD,USER_EMAIL)
values (#{userId},#{userName},#{userPassword},#{userEmail})
</insert>
</mapper>
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- Main.java
package com.mu.mybatis;
import com.mu.mybatis.domain.User;
import com.mu.mybatis.mapper.UserMapper;
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 java.io.InputStream;
import java.io.IOException;
import java.util.List;
/**
* Created by manunited1985 on 2017/11/23.
*/
public class Main {
public static void main(String[] args) throws IOException {
SqlSession session = null;
try {
// 读取配置信息
String resource = "application.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
// 选择不同的环境
String env = "product";
SqlSessionFactory factory = builder.build(inputStream,env);
// 产生SqlSession对象
session = factory.openSession();
System.out.println(session);
// 获取映射对象
UserMapper userMapper = session.getMapper(UserMapper.class);
// 获取id为1的账户
User user = userMapper.selectUserById(1);
System.out.println(user);
// 获取所有账户
List<User> arrayList = userMapper.selectUserAll();
System.out.println(arrayList);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
if (session != null)
// 关闭连接
session.close();
}
}
}
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数据库配置 jdbc.properties
jdbc_driver=com.mysql.jdbc.Driver
jdbc_url=jdbc/:mysql/://127.0.0.1/:3306/test?useUnicode=true&characterEncoding=utf-8
jdbc_username=root
jdbc_password=123456
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应用配置application.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>
<properties resource="jdbc.properties"></properties>
<environments default="development">
<!--配置不同的环境下的数据源-->
<!--开发模式下-->
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc_driver}"/>
<property name="url" value="${jdbc_url}"/>
<property name="username" value="${jdbc_username}"/>
<property name="password" value="${jdbc_password}"/>
</dataSource>
</environment>
<!--生产模式下-->
<environment id="product">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc_driver}"/>
<property name="url" value="${jdbc_url}"/>
<property name="username" value="${jdbc_username}"/>
<property name="password" value="${jdbc_password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/mu/mybatis/mapper/UserMapper.xml"/>
</mappers>
</configuration>
<br/>
运行结果
org.apache.ibatis.session.defaults.DefaultSqlSession@454b70a9
User [userId=1, userName=xiaoming, userPassword=123456, userEmail=x@sina.com]
[User [userId=1, userName=xiaoming, userPassword=123456, userEmail=x@sina.com], User [userId=2, userName=tom, userPassword=123, userEmail=tom@sina.com], User [userId=3, userName=jack, userPassword=123, userEmail=jack@sina.com]]
备注
如果你利用IDEA创建的工程,在加载mapper.xml文件的时候,出现类似现象:
mybatis错误——java.io.IOException: Could not find resource com/xxx/xxxMapper.xml
那么,你可以在pom.xml文件的添加如下字段:
<build>
<!--idea不会寻找src/main/java目录下的xml配置-->
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
</build>
IDEA是不会编译src的java目录的xml文件,所以在Mybatis的配置文件中找不到xml文件!(也有可能是Maven构建项目的问题,网上教程很多项目是普通的Java web项目,所以可以放到src下面也能读取到)
原创文章,作者:Maggie-Hunter,如若转载,请注明出处:https://blog.ytso.com/tech/opensource/195646.html