[文章出處]文章出處
IbatisConfiguration.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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ibatis" />
<property name="username" value="root" />
<property name="password" value="" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="pojo/Account.xml" />
</mappers>
</configuration>
Account.java
package pojo;
public class Account {
private int id;
private String username;
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;
}
}
Account.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">
<mapper namespace="liyixing">
<select id="getAccount" parameterType="string" resultType="pojo.Account">
select * from Account where username = #{username}
</select>
</mapper>
test.java
package test;
import java.io.IOException;
import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import pojo.Account;
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
try {
Reader reader = Resources
.getResourceAsReader("test/IbatisConfiguration.xml");
SqlSessionFactory sqlMapper = new SqlSessionFactoryBuilder()
.build(reader);
Account account = (Account) sqlMapper.openSession().selectOne(
"liyixing.getAccount", "liyixing");
System.out.println("id: " + account.getId());
System.out.println("name: " + account.getUsername());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
基於接口,class調用
上面例子中進行修改,首先添加dao類
package dao;
import pojo.Account;
public interface AccountDao {
public Account getAccount(String name);
}
修改映射文件
<?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="dao.AccountDao">
<select id="getAccount" parameterType="string" resultType="pojo.Account">
select * from Account where username = #{username}
</select>
</mapper>
可以看到,首先要改mapper的namespace值,該值和dao接口的包名完全相同。其次是看接口中的方法名,方法名必須在map文件中,存在相同的id才行,否則會報錯。這種方式可以將dao接口的實現轉移到配置文件中。
修改test類
package test;
import java.io.IOException;
import java.io.Reader;
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 dao.AccountDao;
import pojo.Account;
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
try {
Reader reader = Resources
.getResourceAsReader("test/IbatisConfiguration.xml");
SqlSessionFactory sqlMapper = new SqlSessionFactoryBuilder()
.build(reader);
SqlSession session = sqlMapper.openSession();
AccountDao accountDao = session.getMapper(AccountDao.class);
Account account = accountDao.getAccount("liyixing");
System.out.println("id: " + account.getId());
System.out.println("name: " + account.getUsername());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
這裏通過AccountDao accountDao = session.getMapper(AccountDao.class);方式獲取dao接口的實現。這個實現是ibatis幫助創建的。我們只需要生成對應的配置文件即可。
Account account = accountDao.getAccount("liyixing");
通過調用dao接口的方法,進行數據操作。