文章目录

Mybatis环境搭建1.创建一个空的maven工程，导入jar包2.在数据库中建表3.创建Dao层以及接口 4.配置xml文件测试

Mybatis环境搭建

1.创建一个空的maven工程，导入jar包

我们使用的开发工具为idea2018 成功后我们应该得到这样的目录结构 我们在pom.xml中配置我们所需的jar包

<?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.daixin.mybatis</groupId> <artifactId>mybatis</artifactId> <version>1.0-SNAPSHOT</version> <packaging>jar</packaging> <dependencies> <!-- mybatis依赖坐标 --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.6</version> </dependency> <!-- mysql 依赖坐标--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> <!-- 单元测试坐标依赖--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> </dependencies> </project>

2.在数据库中建表

CREATE TABLE USER ( Id INT(11) PRIMARY KEY AUTO_INCREMENT, UserName VARCHAR(18) DEFAULT NULL, Age INT(11) DEFAULT NULL )user 别忘记添加一些可供我们查询的数据

3.创建Dao层以及接口

package com.daixin.mybatisdemo.domain; public class UserDao { private Integer Id;//注意变量和sql表中相同 private String UserName; private Integer Age; public Integer getId() { return Id; } public void setId(Integer id) { Id = id; } public String getUserName() { return UserName; } public void setUserName(String userName) { UserName = userName; } public Integer getAge() { return Age; } public void setAge(Integer age) { Age = age; } @Override public String toString() { return "UserDao{" + "Id=" + Id + ", UserName='" + UserName + '\'' + ", Age=" + Age + '}'; } } package com.daixin.mybatisdemo.dao; import domain.UserDao; import java.util.List; public interface ImUserDao { /* 用户查询方法 */ List<UserDao> findALL(); }

4.配置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"> <!--mybatis主配置文件--> <configuration> <!--配置环境--> <environments default="mysql"> <!--配置mysql环境--> <environment id="mysql"> <!--配置事务类型--> <transactionManager type="JDBC"></transactionManager> <!--连接池的配置--> <dataSource type="POOLED"> <!--数据库配置的基本信息--> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatisdemo"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <!--指定映射文件配置 --> <mappers> <mapper resource="Mapper.xml"/> </mappers> </configuration> <?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.daixin.mybatisdemo.dao.ImUserDao"> <select id="findALL" resultType="com.daixin.mybatisdemo.domain.UserDao"> select * from user </select> </mapper>

测试

package com.daixin.test; import com.daixin.mybatisdemo.dao.ImUserDao; import com.daixin.mybatisdemo.domain.UserDao; import com.sun.deploy.model.Resource; import jdk.internal.util.xml.impl.Input; 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.util.List; public class Test { public static void main(String[] args) throws Exception{ //1.读取配置文件 InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml"); //2.创建SqlSessionFactory工厂 SqlSessionFactoryBuilder builder=new SqlSessionFactoryBuilder(); SqlSessionFactory factory = builder.build(in); //3.使用工厂生产SqlSession对象 SqlSession sqlSession = factory.openSession(); //4.使用SqlSession工厂创建Dao接口的代理对象 ImUserDao userDao =sqlSession.getMapper(ImUserDao.class); //5.使用代理对象执行方法 List<UserDao> users =userDao.findALL(); for (UserDao user:users ) { System.out.println(user); } //6.释放资源 sqlSession.close(); in.close(); } }

我就们成功了查询到了数据库里的信息