1. 创建Maven工程,pom.xml文件的配置如下:
<?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.cc.mybatis</groupId>
<artifactId>Mybatisdemo01</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.36</version>
</dependency>
<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
需要配置mybatis, mysql驱动,日历log4j, 测试包junit
2. 在resources目录下,添加mybatis的mysql配置文件,例如Mybats-mysql.xml,内容如下:
<?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="dev">
<environment id="dev">
<transactionManager type="JDBC"></transactionManager>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1:3306/student" />
<property name="username" value="root" />
<property name="password" value="1234" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/cc/mybatis/dao/studentMapper.xml"></mapper>
</mappers>
</configuration>
SSM是面向接口编程,在查询数据时,需要些接口,然后再xml文件中配置,例如有一个dao的接口如下:
package com.cc.mybatis.dao;
import com.cc.mybatis.entity.student;
import java.util.List;
public interface studentDao {
List<student> findAll();
}
其中 findAll()的方法,不需要在他的继承类中实现,只需要在xml中配置,如下:
<?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.cc.mybatis.dao.studentDao">
<select id="findAll" resultType="com.cc.mybatis.entity.student">
select * from stinfo
</select>
</mapper>
注意点如下:
(1)mapper namespace的内容是dao类的全路径
(2)查询用select标签
(3)查询的结果用resultType标签
(4)id的值是接口中的方法名
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做好这些即可测试代码了,例如:
// 1. 读取mybatis配置
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
// 2. 创建SqlSessionFactory
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
SqlSessionFactory sqlSessionFactory = builder.build(inputStream);
// 3. 使用工厂生产SqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
// 4. 使用SqlSession对象创建Dao接口的代理对象
studentDao studentDao = sqlSession.getMapper(studentDao.class);
// 5. 使用代理对象执行方法
List<student> studentList = studentDao.findAll();
for (student stu : studentList) {
System.out.println(stu);
}
// 6. 释放资源
sqlSession.close();
inputStream.close();