Mybatis入门配置及第一个Mybatis程序
目的：使用mybatis来进行对数据库表的操作
第一步：引入jar包
我这里是创建的maven工程
第二步：创建数据表user
第三步：创建实体类
实体类放在包 com.xxx.pojo 下，包名可自行修改。实体类中属性名可以和数据库中字段名一致，也可以不一致，推荐一致
public class User { private int id; private String user_name; private String user_sex; private int user_age; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUser_name() { return user_name; } public void setUser_name(String user_name) { this.user_name = user_name; } public String getUser_sex() { return user_sex; } public void setUser_sex(String user_sex) { this.user_sex = user_sex; } public int getUser_age() { return user_age; } public void setUser_age(int user_age) { this.user_age = user_age; } @Override public String toString() { return "User [id=" + id + ", user_name=" + user_name + ", user_sex=" + user_sex + ", user_age=" + user_age + "]"; } public User(String user_name, String user_sex, int user_age) { super(); this.user_name = user_name; this.user_sex = user_sex; this.user_age = user_age; } public User() { super(); } }
第四步：配置Mybatis核心配置文件
Mybatis核心配置文件可以任意取名，也可以放在任意路径下。在这里，我的配置文件名称是：mybatis-config.xml，而且是放在了src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> <!-- 配置数据库环境 default：指定默认的数据库--> <environments default="mysql"> <!-- id：数据库的名称，唯一的 --> <environment id="mysql"> <!-- 事务管理 交给jdbc管理--> <transactionManager type="jdbc"></transactionManager> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/test"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> <environment id="oracle"> <transactionManager type="jdbc"></transactionManager> <dataSource type="POOLED"> <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@//localhost:1521/数据库名"/> <property name="username" value="用户名"/> <property name="password" value="密码"/> </dataSource> </environment> </environments> <!-- 映射文件 --> <mappers> <mapper resource="com/xxx/pojo/UserMapper.xml"/> </mappers> </configuration>
在编写核心配置文件的时候，你可能会发现 alt+/ 没有给出提示，这是因为你没有将mybatis的核心配置文件的约束引入eclipse，引入方法：
在浏览器上地址栏输入：http://mybatis.org/dtd/mybatis-3-config.dtd，会进入 dtd 约束文件下载，接着点击window--->preferences-->搜索xml--->选择xml Catelog
点击 add
Location：你下载的 dtd 文件的的路径
Key type：URI
Key：http://mybatis.org/dtd/mybatis-3-config.dtd
第五步：编写实体类映射文件
<?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.xxx.pojo.User"> <!-- 对返回值数据的映射规则 --> <resultMap type="com.xxx.pojo.User" id="UserMap"> <id property="id" column="id"/> <result property="user_name" column="user_name"/> <result property="user_sex" column="user_sex"/> <result property="user_age" column="user_age"/> </resultMap> <!-- 编写插入语句 parameterType:传入的参数类型--> <insert id="insert1" parameterType="com.xxx.pojo.User"> insert into user(user_name,user_sex,user_age)values(#{user_name},#{user_sex},#{user_age}) </insert> <update id="update1" parameterType="com.xxx.pojo.User"> update user set user_name=#{user_name},user_sex=#{user_sex},user_age=#{user_age} where id=#{id} </update> <delete id="delete1" parameterType="int"> delete from user where id=#{id} </delete> <select id="select1" resultMap="UserMap"> select *from user </select> </mapper>
第六步：测试
编写测试类，进行测试框架
package com.xxx.test; import java.io.IOException; import java.io.InputStream; import java.util.ArrayList; import java.util.List; 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 com.xxx.pojo.User; public class TestCase { private static SqlSession session; public static SqlSession getSqlSession(){ try {
//读取mybatis核心配置文件 InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
//获取SqlSessionFactory工厂对象 SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//获取SqlSession对象 session = sqlSessionFactory.openSession(); } catch (IOException e) { e.printStackTrace(); } return session; } public static void close(){ if(session!=null){ session.close(); } } /* * 测试插入 */ @Test public void test1(){ SqlSession sqlSession = getSqlSession(); User user = new User("张三", "男", 20); sqlSession.insert(User.class.getName()+".insert1", user);
//每次对数据库发生改变之后，不要忘记提交 sqlSession.commit(); close(); } /* * 测试更新数据 */ @Test public void test2(){ SqlSession sqlSession = getSqlSession(); User user = new User("张三", "男", 20); user.setUser_age(30); user.setId(4); sqlSession.update("com.wangtong.pojo.User.update1", user); sqlSession.commit(); close(); } /* * 测试删除 */ @Test public void test3(){ SqlSession sqlSession = getSqlSession(); sqlSession.delete(User.class.getName()+".delete1", 5); sqlSession.commit(); close(); } /* * 测试查询 */ @Test public void test4(){ SqlSession sqlSession = getSqlSession(); List<User> list = sqlSession.selectList(User.class.getName()+".select1"); System.out.println(list); sqlSession.commit(); close(); } }
