这篇博文通过简单的CRUD案例,让大家能够快速的上手,使用mybatis。
1,在eclipse中新建java project项目 mybatis_demo
2,在mybatis_demo项目中建立lib文件夹并导入如下jar文件
并将jar包build path中
3,在项目下创建如下目录
注意:config是source folder文件用于保存配置文件,
4,在source folder下加入mybatis的核心配置文件SqlMapperCofing.xml
<?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> <!-- 导入外部属性文件 --> <properties resource="jdbc.properties" /> <!-- 配置mybatis的开发环境 --> <environments default="development"> <environment id="development"> <!-- 配置mybatis的事物管理方式 --> <transactionManager type="JDBC" /> <!-- 配置数据库连接 --> <dataSource type="POOLED"> <property name="driver" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </dataSource> <!-- <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/mybatis_01?characterEncoding=utf-8"/> <property name="username" value="root"/> <property name="password" value="123"/> </dataSource> --> </environment> </environments> <!-- 配置mapper映射 --> <mappers> <mapper resource="mapper/user.xml"/> </mappers> </configuration>
加入log4j.properties文件
# Global logging configuration log4j.rootLogger=DEBUG, stdout # Console output... log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
加入jdbc.properties文件
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/mybatis_01?characterEncoding=utf-8 jdbc.username=root jdbc.password=123
(注意:其中的一些数据库配置,按照自己的数据库配置进行修改)
5,在src目录下新建User类
package com.mybatis.pojo; import java.util.Date; /** * 用户实体类 * @author Administrator * */ public class User { private Integer id; private String username;// 用户名 private String sex;// 性别 private Date birthday;// 出生日期 private String address;// 家庭住址 public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "User [id=" + id + ", username=" + username + ", sex=" + sex + ", birthday=" + birthday + ", address=" + address + "]"; } }
并创建与实体类对应的数据库表user。
6,在mapper下新建user.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="user"> <!-- 全查user类 --> <select id="listUser" resultType="com.mybatis.pojo.User"> select id, username, sex, birthday, address from user </select> </mapper>
7,添加测试文件demo.java
package com.mybatis.test; import java.io.IOException; import java.io.InputStream; import java.util.Date; 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.mybatis.pojo.User; import com.mybatis.utils.MybatisUtil; public class Demo { /** * 全查user表测试 */ @Test public void listUser(){ try { //1,加载mybatis核心配置文件SqlMapperConfig.xml InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapperConfig.xml"); //2,创建SqlSessionFactory对象 SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream); //3,创建SessionFactory SqlSession session = sqlSessionFactory.openSession(); String statement = "user.listUser"; List<User> userList = session.selectList(statement); for (User user : userList) { System.out.println(user); } session.commit(); session.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
8,利用junit 运行方法得到结果
到此,简单的mybatis项目完成。