一、 Mybatis HelloWorld
1. 应用Maven创立一个我的项目,我的项目目录如下
2. 在maven 的pom.xml引入依赖
次要包含mybatis,mysql,junit的依赖，而后就可进行开发了。
<?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>org.example</groupId> <artifactId>test03</artifactId> <version>1.0-SNAPSHOT</version> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.7</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.22</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.13.2</version> <scope>test</scope> </dependency> </dependencies></project>3. 编写mybatis配置文件 mybatis-config.xml文件
次要是用来配置数据源 和 配置相干mapper*.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"><configuration> <environments default="development"> <environment id="development"> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <mapper resource="UserMapper.xml"/> </mappers></configuration>4.创立用户表,编写User类
package com.jt;public class User { private int id; private String username; private String password; 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; } @Override public String toString() { return "User{" + "id=" + id + ", username='" + username + '\'' + ", password='" + password + '\'' + '}'; }}5.编写UserMapper类
package com.jt;import org.apache.ibatis.annotations.Param;import org.apache.ibatis.annotations.Select;import java.util.Map;public interface UserMapper { public User selectUser(int id); public User selectUserByIdAndName(@Param("id") Integer id,@Param("username") String username); public User selectUserByIdAndNameUseMap(Map map); public Integer insertUser(User user); public boolean updateUser(User user); public Integer deleteUserById(int id);}6.编写UserMapper.xml文件
<?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.jt.UserMapper"> <select id="selectUser" resultType="com.jt.User"> select * from test01 where id = #{id} </select> <select id="selectUserByIdAndName" resultType="com.jt.User"> select * from test01 where id = #{id} and username=#{username} </select> <select id="selectUserByIdAndNameUseMap" resultType="com.jt.User"> select * from test01 where id = #{id} and username=#{username} </select> <insert id="insertUser" useGeneratedKeys="true" keyProperty="id"> insert into test01 (username,password) values(#{username},#{password}) </insert> <update id="updateUser" parameterType="com.jt.User"> update test01 set username=#{username} where id=#{id} </update> <delete id="deleteUserById"> delete from test01 where id=#{id} </delete></mapper>7.编写测试类
import com.jt.User;import com.jt.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 org.junit.Test;import java.io.IOException;import java.io.InputStream;import java.util.LinkedHashMap;import java.util.Map;public class HelloTest { @Test public void selectTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); User user = userMapper.selectUser(1); System.out.println(user); }finally { sqlSessionFactory.openSession(); } } @Test public void selectByIdAndNameTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); User user = userMapper.selectUserByIdAndName(5,"3"); System.out.println(user); }finally { sqlSessionFactory.openSession(); } } @Test public void selectByIdAndNameUseMapTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); Map map = new LinkedHashMap(); map.put("id",5); map.put("username","3"); User user = userMapper.selectUserByIdAndNameUseMap(map); System.out.println(user); }finally { sqlSessionFactory.openSession(); } } @Test public void insertTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); User user01 = new User(); user01.setUsername("4"); user01.setPassword("4"); userMapper.insertUser(user01); System.out.println(user01.getId()); }finally { sqlSessionFactory.openSession(); } } @Test public void updateTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); User user01 = new User(); user01.setId(2); user01.setUsername("批改1"); boolean res = userMapper.updateUser(user01); System.out.println(res); }finally { sqlSessionFactory.openSession(); } } @Test public void deleteTest() throws IOException { String resource = "mybatis-config.xml"; InputStream inputStream = Resources.getResourceAsStream(resource); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); try (SqlSession session = sqlSessionFactory.openSession()) { UserMapper userMapper = session.getMapper(UserMapper.class); int res = userMapper.deleteUserById(1); System.out.println(res); }finally { sqlSessionFactory.openSession(); } }}