Mybatis使用篇之二：HelloWorld

1. 搭建开发环境

（1）新建一个Web工程，名称为MybatisFramework。

 

（2）将以下的JAR放到Web工程的lib下面：

 mybatis- 3.0 . 6 .jar
 og4j-1.2 . 16 .jar
 classes12.jar

 

（3）在src下面新建log4j.properties文件，该文件的内容如下：

 log4j.appender.stdout=org.apache.log4j.ConsoleAppender
 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
 log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] -%m%n
 log4j.logger.com.ibatis=debug
 log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debug
 log4j.logger.com.ibatis.common.jdbc.ScriptRunner=debug
 log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debug
 log4j.logger.java.sql.Connection=debug
 log4j.logger.java.sql.Statement=debug
 log4j.logger.java.sql.PreparedStatement=debug,stdout

 

（4）在src下面新建mybatis.cfg.xml文件，该文件的内容如下：

 <?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= "oracle.jdbc.OracleDriver"  />
               <property name="url"  value= "jdbc:oracle:thin:@localhost:1521:SID"  />
               <property name="username"  value= "xxxx"  />
               <property name="password"  value= "xxxx"  />
             </dataSource>
         </environment>
     </environments>

     </configuration>

 

 

2. 入门示例

（1）在Oracle数据库执行以下SQL，创建一个USER_INFO的表：

 -- Create table
 create table USER_INFO
 (
   ID          NUMBER(12 ) not  null ,
   NAME        VARCHAR2(50 )
 );

 --Insert data
 insert into USER_INFO(ID,NAME) values(1 , '张三' );

 

（2）新建一个Java类UserInfo.java，该类的内容如下：

 

 package  com.user;

 public   class  UserInfo {
     private   int  id;
     private  String name;

     public  UserInfo() {
     }

     public  UserInfo(String name) {
         this ( 0 , name);
     }

     public  UserInfo( int  id, String name) {
         this .id = id;
         this .name = name;
     }

     public   int  getId() {
         return  id;
     }

     public   void  setId( int  id) {
         this .id = id;
     }

     public  String getName() {
         return  name;
     }

     public   void  setName(String name) {
         this .name = name;
     }

     @Override
     public  String toString() {
         return   "ID: "  + id +  ", Name: "  + name;
     }
 }

 

（3）在com.user.sqlmap下面新建UserInfo.xml文件，该文件的内容如下：

 

 <?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" >
     <select id="selectUser"  parameterType= "int"  resultType= "UserInfo" >
     <![CDATA[
         select * from user_info where id = #{id}
     ]]>
     </select>
 </mapper>

 

（4）将UserInfo.xml引用到mybatis.cfg.xml文件中，mybatis.cfg.xml文件更新后的内容如下：

 <?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>
     <typeAliases>
         <typeAlias alias="UserInfo"  type= "com.user.UserInfo"  />
     </typeAliases>

     <environments default = "development" >
         <environment id="development" >
             <transactionManager type="JDBC"  />
             <dataSource type="POOLED" >
               <property name="driver"  value= "oracle.jdbc.OracleDriver"  />
               <property name="url"  value= "jdbc:oracle:thin:@localhost:1521:ORACLEDB"  />
               <property name="username"  value= "oracle"  />
               <property name="password"  value= "oracle"  />
             </dataSource>
         </environment>
     </environments>

     <mappers>
         <mapper resource="com/user/sqlmap/UserInfo.xml"  />
     </mappers>
 </configuration>

 

（5）新建一个测试Java类UserInfoTest.java，该类的具体内容如下：

 package  com.user;

 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;



 public   class  UserInfoTest {

     /**
      * @param args
      * @throws IOException
      */
     public   static   void  main(String[] args)  throws  IOException {
         String resource = "mybatis.cfg.xml" ;
         Reader reader = Resources.getResourceAsReader(resource);
         SqlSessionFactory ssf = new  SqlSessionFactoryBuilder().build(reader);

         SqlSession session = ssf.openSession();

         try  {
             UserInfo user = (UserInfo) session.selectOne("User.selectUser" ,  "1" );
             System.out.println(user);
         } catch  (Exception e) {
             e.printStackTrace();
         } finally  {
             session.close();
         }
     }

 }

 

（6）右键UserInfoTest 类，选择Run As Application，运行MyBaits操作数据库。

 

 log4j:WARN No appenders could be found  for  logger (org.apache.ibatis.logging.LogFactory).
 log4j:WARN Please initialize the log4j system properly.
 log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
 2012 - 02 - 11   21 : 44 : 01 , 750  DEBUG [java.sql.PreparedStatement] -==>  Executing: select * from user_info where id = ?
 2012 - 02 - 11   21 : 44 : 01 , 781  DEBUG [java.sql.PreparedStatement] -==> Parameters:  1 (String)
 ID: 1 , Name: 张三