我也刚刚开始初学，先来一个小例子：
创建一个User.java文件，代码如下：
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package com.rollen;
public class User {
private String name;
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Name:"+name+"Age"+age;
}
} |
上面的java文件位于com.rollen包中，然后在这个包中建立generator.xml文件，代码为：
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<?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="User" type="com.rollen.User" />
</typeAliases>
<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/user_db" />
<property name="username" value="root" />
<property name="password" value="root" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/rollen/user.xml" />
</mappers>
</configuration>
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在com.rollen包下面创建user.xml文件，代码为：
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<?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="com.rollen.User">
<select id="selectUser" parameterType="int" resultType="User" >
select * from user where age = #{age}
</select>
</mapper>
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我们最后编写一个测试类，代码如下“：
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package com.rollen;
import java.io.*;
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 Test {
public static void main(String[] args) {
String resource="com/rollen/generatorConfig.xml";
Reader reader = null;
try {
reader = Resources.getResourceAsReader(resource);
} catch (IOException e) {
e.printStackTrace();
}
SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(reader);
SqlSession sqlSession = factory.openSession();
try {
User user=sqlSession.selectOne("selectUser", 10);
System.out.println(user);
}finally{
sqlSession.close();
}
}
} |
在上面的generateConfig.xml文件中，也可以改为这样：
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<?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>
<properties>
<property name="username" value="root" />
</properties>
<typeAliases>
<typeAlias alias="User" type="com.rollen.User" />
</typeAliases>
<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/user_db" />
<property name="username" value="${username}" />
<property name="password" value="root" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/rollen/user.xml" />
</mappers>
</configuration>
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注意，和上面的区别是我们添加了：
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<properties>
<property name="username" value="root" />
</properties>
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并且修改了这行代码：
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<property name="username" value="${username}" />
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还可以有如下的修改方法，新建一个config.properties文件，文件内容为：
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password=root |
然后将generatorconfig.xml文件的内容改为：
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<?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>
<properties resource="com/rollen/config.properties">
<property name="username" value="root" />
</properties>
<typeAliases>
<typeAlias alias="User" type="com.rollen.User" />
</typeAliases>
<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/user_db" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/rollen/user.xml" />
</mappers>
</configuration>
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需要注意的是如下的两行代码：
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<properties resource="com/rollen/config.properties">
....<property name="password" value="${password}" />
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==============================================================================
本文转自被遗忘的博客园博客，原文链接：http://www.cnblogs.com/rollenholt/archive/2012/11/06/2757553.html，如需转载请自行联系原作者