普通模式
自定义接口，接口实现类。
思考：需要sqlSessionFactory，生产sqlSession。
UserDao:
package dao;
import java.util.List;
import domain.User;
public interface UserDao {
//根据Id查询用户
public User findUserByID(Integer id);
//根据用户名进行模糊查询
public List<User> findUserByUsername(String username);
}
UserDaoImpl:
package dao.impl;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import dao.UserDao;
import domain.User;
public class UserDaoImpl implements UserDao{
//namespace
private String ns="test.";
private SqlSessionFactory sqlSessionFactory;
public UserDaoImpl(SqlSessionFactory sqlSessionFactory){
this.sqlSessionFactory=sqlSessionFactory;
}
public User findUserByID(Integer id) {
SqlSession sqlSession=sqlSessionFactory.openSession();
User user = sqlSession.selectOne(ns+"findUserByID",id);
return user;
}
public List<User> findUserByUsername(String username) {
SqlSession sqlSession=sqlSessionFactory.openSession();
List<User> list=sqlSession.selectList(ns+"findUserByUsername", username);
return list;
}
}
Main3:
package test;
import static org.hamcrest.CoreMatchers.nullValue;
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.Before;
import org.junit.Test;
import dao.UserDao;
import dao.impl.UserDaoImpl;
import domain.User;
public class Main3 {
SqlSessionFactory sqlSessionFactory=null;
@Before
public void beforeConf() throws IOException{
String resources="sqlMapConfig.xml";
InputStream inputStream=Resources.getResourceAsStream(resources);
sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
}
//普通dao开发模式
@Test
public void commonDao(){
UserDao userDao=new UserDaoImpl(sqlSessionFactory);
//根据Id查询用户
User user1 = userDao.findUserByID(16);
System.out.println("user1:::"+user1);
//根据名字模糊查询用户
List<User> list = userDao.findUserByUsername("张");
System.out.println(list);
}
}
接口代理开发模式
自需要定义接口。
开发约定：
l 映射文件namespace必须是接口全类路径名。
l 映射文件的Statement的id必须和接口的方法名一致。
sqlMapConfig.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"> <!-- 配置文件开始，所有配置文件都必须在configuration --> <configuration> <!-- 可以配置多个运行环境，但是每个 SqlSessionFactory 实例只能选择一个运行环境 一、development:开发模式 二、work：工作模式--> <environments default="development"> <!--id属性必须和上面的default一样 --> <environment id="development"> <!-- mybatis事务管理器 ,由jdbc管理--> <transactionManager type="JDBC"/> <!-- mybatis连接池 --> <dataSource type="POOLED"> <property name="driver" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql:///mybatis01"/> <property name="username" value="root"/> <property name="password" value="moujinling321"/> </dataSource> </environment> </environments> <!-- 引入外部映射文件 --> <mappers> <mapper resource="sqlMap/User.xml"/> </mappers> </configuration>
User.xml:
<?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">
<!--
MyBatis映射文件的开始标签 ,所有sql语句全部封装在mapper里面
namespace:命名空间
*隔离不同的映射文件，映射文件的唯一标识，可以任意命名
*在接口代理开发中，namespace具有特殊含义，不能任意命名
namespace需要写接口的全路径
-->
<mapper namespace="dao.UserMapper">
<!-- statement的id必须和接口中的方法名相同 -->
<select id="findUserByID" parameterType="int" resultType="domain.User">
select * from user where id=#{id}
</select>
<select id="findUserByUsername" resultType="domain.User" parameterType="string">
select * from user where username like ‘%${value}%‘
</select>
</mapper>
UserMapper:
package dao;
import java.util.List;
import domain.User;
public interface UserMapper {
//根据Id查询用户
public User findUserByID(Integer id);
//根据用户名进行模糊查询
public List<User> findUserByUsername(String username);
}
Main1:
package test;
import java.io.IOException;
import java.io.InputStream;
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.Before;
import org.junit.Test;
import dao.UserMapper;
import domain.User;
public class Main1 {
SqlSessionFactory sqlSessionFactory=null;
@Before
public void beforeConf() throws IOException{
String resources = "sqlMapConfig.xml";
InputStream inputStream = Resources.getResourceAsStream(resources);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
}
//接口代理开发模式
@Test
public void proxyInterface(){
SqlSession sqlSession=sqlSessionFactory.openSession();
//获取代理对象
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
//根据Id查询
User user = userMapper.findUserByID(24);
System.out.println(user);
//根据用户名进行模糊查询
List<User> users=userMapper.findUserByUsername("张");
System.out.println(users);
}
}