Mybatis的简单使用步骤（java项目） 4000

1、在eclipse中创建mavenjava项目（jar）,并初始化依赖,放入log4j的配置文件

pom文件如下（一个是Mybatis必须的，一个是log4j的日志）

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.iflytek</groupId>
<artifactId>Mybatis1</artifactId>
<version>0.0.1-SNAPSHOT</version>

<dependencies>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>

<!-- https://mvnrepository.com/artifact/log4j/log4j -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
</dependencies>

</project>

放入log4j的配置文件（log4j.properties）

# Global logging configuration
log4j.rootLogger=ERROR, stdout
# MyBatis logging configuration...
log4j.logger.com.iflytek=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

2、创建mybatis-config.xml文件，指定最基本的environments和mappers，这里我用外部加载数据库配置文件jdbc.properties

jdbc.properties如下

jdbc.driverClassName=oracle.jdbc.driver.OracleDriver
jdbc.url=jdbc:oracle:thin:@172.16.130.35:1521:orcl
jdbc.username=uuid
jdbc.password=uuid

hibernate.dialect=org.hibernate.dialect.Oracle10gDialect
hibernate.hbm2ddl.auto=update
hibernate.show_sql=true
hibernate.format_sql=true

mybatis-config.xml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>
<properties resource="jdbc.properties" />

<!-- 设置整个包下的文件都以自己的类名为别名 ，不然在之后的mapper.xml中要写类的全路径-->
<typeAliases>
<package name="com.iflytek.domain" />
</typeAliases>

<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />

</dataSource>
</environment>
</environments>
<!-- 将映射的文件指定到类中而不是资源文件中，可用resource 或者class指定到资源文件中 -->
<mappers>
<package name="com.iflytek.dao"/>
</mappers>
</configuration>3、创建对应的pojo, mapper.xml文件和对应在dao中的接口，这里用Blog.java, BlogMapper.xml和BlogMapper.java三个文件
Blog.java

package com.iflytek.domain;

public class Blog {
private int id;
private String title;
private String auth;

public int getId() {
return id;
}

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

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

public String getAuth() {
return auth;
}

public void setAuth(String auth) {
this.auth = auth;
}

@Override
public String toString() {
return "Blog [id=" + id + ", title=" + title + ", auth=" + auth + "]";
}

}
BlogMapper.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="com.iflytek.dao.BlogMapper">

<!-- 当数据库的字段与pojo的字段不匹配时，要指定resultMap,下面指定resultMap 而不是resultType column为数据库的，property为pojo的 -->
<resultMap type="Blog" id="bid">
<id column="id" property="id" />
<result column="title1" property="title" />
<result column="auth1" property="auth" />
</resultMap>

<!--select,insert,update,delete四个标签定义sql语句，每一个标签对应一条接口中的抽象方法 -->
<select id="selectBlog" resultMap="bid">
select *
from tt_blog where id = #{id}
</select>

<insert id="saveBlog" parameterType="Blog">
insert into tt_blog (id,title) values(SEQ_BLOG.nextval,#{title})
</insert>

<update id="updateBlog" parameterType="Blog">
update tt_blog set title = #{title}
<!-- 动态sql，当想更新的内容不为空的时候，则会执行，否则将不会执行 -->
<if test="auth != null">
,auth = #{auth}
</if>
where id = #{id}
</update>

<delete id="deleteBlog">
delete from tt_blog where id = #{id}
</delete>
</mapper>BlogMapper.java
package com.iflytek.dao;

import com.iflytek.domain.Blog;

public interface BlogMapper {
public Blog selectBlog(Blog blog);
public void saveBlog(Blog blog);
public void updateBlog(Blog blog);
public void deleteBlog(Blog blog);

}


4、代建对应的数据库和表，本例创建如下



初始化部分数据



5、创建测试类进行测试，这里对SQLsessionfactory还没有进行封装，开发中一般使用单例模式进行封装，只有一个工厂sessionfactory，可有多个session对象（Test.java）

package com.iflytek.test;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import com.iflytek.dao.BlogMapper;
import com.iflytek.domain.Blog;

public class Test {
public static void main(String[] args) throws IOException {

String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

SqlSession session = sqlSessionFactory.openSession();
try {

BlogMapper mapper = session.getMapper(BlogMapper.class);

Blog blog = new Blog();
blog.setId(1);

Blog res = mapper.selectBlog(blog);

System.out.println(res.getTitle());
} finally {
session.close();
}
}
}


6、查看结果（id为1的对应title为1111），正确


’