mybatis 初學 小例子

今天終於把它弄清楚了，剛剛學java，挺費勁呀。

在mysql中創建一個數據庫mygps,表名爲test(id,age,username,password)

(1)先引用mybatis-3.0.2.jar，mysql-connector-java-5.0.8-bin.jar

(2)配置連接數據庫xml文件取名叫config.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/mygps"/>//數據庫名爲mypgs
    <property name="username" value="root"/>
    <property name="password" value="root"/>
   </dataSource>
  </environment>
 </environments>
<mappers>
 <mapper resource="org/mybatis/test/testmapper.xml"/>//寫sql語句的xml
</mappers>
</configuration>

（3）配置sql語句的xml取名叫testmapper.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="testmapper">
 <select id="selectbyid" parameterType="int" resultType="org.mybatis.test.test">//test爲一個類，用於設置與數據庫有關的數據類型
  select * from test where test.id=#{id}
 </select>
 <insert id="insertvalues" parameterType="org.mybatis.test.test">
     insert into test (id,username,password,age) values (#{id},#{username},#{password},#{age})
 </insert>
 <update id="updatevalue" parameterType="org.mybatis.test.test">
     update test set username=#{username} where id=#{id}
    </update>

</mapper>

(4)取出數據庫的連接取名叫util 是一個類

package org.mybatis.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;
public class util {

 public static SqlSessionFactory sqlmapper=null;

 static
 {
  String rs="org/mybatis/test/config.xml";//爲第二步中的配置文件名
  Reader reader=null;
  try
  {
      reader=Resources.getResourceAsReader(rs);

  }
  catch(IOException e)
  {
   e.printStackTrace();
  }
  sqlmapper=new SqlSessionFactoryBuilder().build(reader);
 }
 public static SqlSessionFactory getSqlSessionFactory()
 {
        return sqlmapper;
 }
}

(5)執行sql語句取名叫getTest 是一個類

package org.mybatis.test;
import org.mybatis.test.util;
import org.mybatis.test.test;
import org.apache.ibatis.session.SqlSession;
public class getTest {

 public test  getvalue(int id)
 {
  SqlSession session=  util.getSqlSessionFactory().openSession();
       test ts=null;
       try
       {
    ts=(test)session.selectOne("testmapper.selectbyid",id);//爲第三步中配置文件中的select id

       }
  catch(Exception e)
  {
   e.printStackTrace();
  }
  finally
  {
   session.close();
  }
  return ts;

 }
 public void insertvalue(int id, String username,String password,int age)
 {
     SqlSession session=  util.getSqlSessionFactory().openSession();
        test ts=new test();
        ts.SetID(id);
        ts.SetUserName(username);
        ts.SetPassWord(password);
        ts.SetAge(age);
        try
        {
    session.selectOne("testmapper.insertvalues",ts);)//爲第三步中配置文件中的insert id

        }
   catch(Exception e)
   {
    e.printStackTrace();
   }
   finally
   {
    session.close();
   }
 }
 public void updatevalue(int id,String username)
 {
     SqlSession session=  util.getSqlSessionFactory().openSession();
        test ts=new test();
        ts.SetID(id);
        ts.SetUserName(username);
        try
        {
        session.selectOne("testmapper.updatevalue",ts);)//爲第三步中配置文件中的update id
        }
   catch(Exception e)
   {
    e.printStackTrace();
   }
   finally
   {
    session.close();
   }
 }

}
(6)爲數據源編寫test類

package org.mybatis.test;

public class test {
private int id;
private int age;
private String username;
private String password;

 public int getID()
 {
  return this.id;
 }
 public void SetID(int id)
 {
 this.id=id;
 }

 public int getAge()
 {
  return this.age ;
 }
 public void SetAge(int age)
 {
     this.age=age;
 }

 public String getUserName()
 {
  return this.username ;
 }
 public void SetUserName(String username)
 {
 this.username =username;
 }

 

public String getPassWord()
 {
  return this.password ;
 }
 public void SetPassWord(String password)
 {
    this.password =password;
 }
}