Mybatis使用篇之二：HelloWorld

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　　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