使用IDEA搭建mybatis
- 建立一个maven项目,导入所需要的依赖
1.mysql依赖
2.mybatis依赖
3.junit依赖
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
</dependencies>
- 导入核心配配置文件一般放在resources中 官方给定文件名为 mybatis-config.xml
<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<!-- configuration核心配置文件-->
<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://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=UTF-8"/>
<property name="username" value="xxxxx"/>
<property name="password" value="xxxxx"/>
</dataSource>
</environment>
</environments>
<mappers>
这个是指向下面的dao中的xml 可以参考最下面的目录结构
<mapper resource="cn/at99guoke/dao/UserMapper.xml"/>
</mappers>
</configuration>
环境是可以有多套的,但只能使用一个
以防Maven读不到src中的xml、pro文件需要在pom.xml中加入配置
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.xml</include>
使用pro的需要在这个地方再加
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
如果没有加会报以下异常
- 编写工具类获取 SqlSession
package cn.at99guoke.utils;
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.IOException;
import java.io.InputStream;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory;
static {
String resource = "mybatis-config.xml";
try {
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
} catch (IOException e) {
e.printStackTrace();
}
}
public static SqlSession getSqlSession(){
return sqlSessionFactory.openSession();
}
}
- 编写Musql对应的实体类添加对应的set、get等方法
package cn.at99guoke.pojo;
public class User {
private int id;
private String name;
private String pwd;
public User(int id, String name, String pwd) {
this.id = id;
this.name = name;
this.pwd = pwd;
}
public User() {
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", name='" + name + '\'' +
", pwd='" + pwd + '\'' +
'}';
}
}
- 编写接口
package cn.at99guoke.dao;
import cn.at99guoke.pojo.User;
import java.util.List;
public interface UserMapper {
List<User> getUserMapper();
}
- 编写接口对应的xml文件
<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.at99guoke.dao.UserMapper">
<select id="getUserMapper" resultType="cn.at99guoke.pojo.User">
select * from User where 1=1
</select>
</mapper>
- 编写测试
package cn.at99guoke.dao;
import cn.at99guoke.pojo.User;
import cn.at99guoke.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import java.util.List;
public class userMapperTses {
@Test
public void test01(){
SqlSession sqlSession = MybatisUtils.getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
List<User> userMapper = mapper.getUserMapper();
for (User user : userMapper) {
System.out.println(user);
}
sqlSession.close();
}
}
- 在测试的时候可能会出现不支持版本5的异常
目录结构大概是这个样子的