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.jarog4j-1.2.16.jarclasses12.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.ConsoleAppenderlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%d %p [%c] -%m%nlog4j.logger.com.ibatis=debuglog4j.logger.com.ibatis.common.jdbc.SimpleDataSource=debuglog4j.logger.com.ibatis.common.jdbc.ScriptRunner=debuglog4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=debuglog4j.logger.java.sql.Connection=debuglog4j.logger.java.sql.Statement=debuglog4j.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 tablecreate table USER_INFO( ID NUMBER(12) not null, NAME VARCHAR2(50));--Insert datainsert 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;}@Overridepublic 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
?
?
?
?
?
?
?
?