mybatis的使用
1.导入jar包
asm-3.3.1.jar
cglib-2.2.2.jar
commons-logging-1.1.1.jar
log4j-1.2.16.jar
mybatis-3.1.1.jar
mysql-connector-java-5.1.10-bin.jar
slf4j-api-1.6.2.jar
slf4j-log4j12-1.6.2.jar
2.创建一个总的配置文件
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE configuration 3 PUBLIC "-//mybatis.org//DTD Config 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-config.dtd"> 5 <configuration> 6 <typeAliases> 7 <!--给实体类起一个别名 user --> 8 <typeAlias type="com.kite.mybatis.domain.User" alias="User" /> 9 </typeAliases> 10 <!-- 配置数据源 --> 11 <environments default="development"> 12 <environment id="development"> 13 <transactionManager type="jdbc" /> 14 <dataSource type="POOLED"> 15 <property name="driver" value="com.mysql.jdbc.Driver" /> 16 <property name="url" value="jdbc:mysql://localhost:3306/mybatis" /> 17 <property name="username" value="root" /> 18 <property name="password" value="aaa123456" /> 19 </dataSource> 20 </environment> 21 </environments> 22 <!-- 映射文件也是dao的实现类 --> 23 <mappers> 24 <mapper resource="com/kite/mybatis/domain/UserMapper.xml" /> 25 </mappers> 26 </configuration>
3.创建实体类
1 package com.kite.mybatis.domain; 2 3 public class User 4 { 5 private String id; 6 private String name; 7 private String age; 8 public String getId() 9 { 10 return id; 11 } 12 public void setId(String id) 13 { 14 this.id = id; 15 } 16 public String getName() 17 { 18 return name; 19 } 20 public void setName(String name) 21 { 22 this.name = name; 23 } 24 public String getAge() 25 { 26 return age; 27 } 28 public void setAge(String age) 29 { 30 this.age = age; 31 } 32 33 }
4.创建dao类
1 package com.kite.mybatis.dao; 2 3 import java.util.List; 4 5 import com.kite.mybatis.domain.User; 6 7 public interface UserMapper 8 { 9 public List<User> selectAll(); 10 }
5.创建user的映射文件 因为要作为userMapper的实现所以在 文件的头部<mapper namespace="com.kite.mybatis.dao.UserMapper"> 必需与dao类对应
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE mapper 3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 5 <mapper namespace="com.kite.mybatis.dao.UserMapper"> 6 <select id="selectAll" resultType="user"> 7 select * from user 8 </select> 9 </mapper>
6.测试
1 package com.kite.mybatis.test; 2 3 import java.io.IOException; 4 import java.util.List; 5 6 import org.apache.ibatis.io.Resources; 7 import org.apache.ibatis.session.SqlSession; 8 import org.apache.ibatis.session.SqlSessionFactory; 9 import org.apache.ibatis.session.SqlSessionFactoryBuilder; 10 11 import com.kite.mybatis.dao.UserMapper; 12 import com.kite.mybatis.domain.User; 13 14 public class MyBatisTest 15 { 16 public static void main(String[] args) throws IOException 17 { 18 //记载mybatis的配置文件 19 SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(Resources.getResourceAsReader("configuraction.xml")); 20 //创建打开sesison 21 SqlSession session = factory.openSession(); 22 UserMapper userDao = session.getMapper(UserMapper.class); 23 List<User> userList = userDao.selectAll(); 24 25 System.out.println(userList.size()); 26 } 27 }
一个mybatis的简单测试