1.导入mybatis的jar包：mybatis-x.x.x.jar
2.使用XML配置mybatis，创建SqlSessionFactory
XML配置文件的名称通常为mybatis-config.xml,内容基本格式如下：
代码语言：javascript复制<?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.driver.OracleDriver"/>
<property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
<property name="username" value="username"/>
<property name="password" value="password"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="org/mybatis/example/BlogMapper.xml"/>
<!-- <package name="com.example.manager.mapper"/> -->
</mappers>
</configuration>该配置文件使用文件流的形式读入，通过mybatis的工具类Resources加载资源文件：
代码语言：javascript复制String resource = "org/mybatis/example/mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);3.从 SqlSessionFactory 中获取 SqlSession
代码语言：javascript复制SqlSession session = sqlSessionFactory.openSession();
try {
Blog blog = (Blog) session.selectOne("org.mybatis.example.BlogMapper.selectBlog", 101);
} finally {
session.close();
}4.最简单的使用方法：mybatis-config.xml mapper.xml test.java
mybatis-config.xml配置
代码语言：javascript复制<mapper resource="org/mybatis/example/BlogMapper.xml"/>resource的路径通常为包路径，众多mapper.xml通常被放置在一个包下
------------------------------------
mapper.xml
代码语言：javascript复制<?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="org.mybatis.example.BlogMapper">
<select id="selectBlog" resultType="Map">
select * from Blog where id = #{id}
</select>
</mapper>namespace：命名空间，映射查询的关键参数
id：调用方法定义
resultType：结果集对象类型（Map可以被HashMap接收，然后转为json，也可以自定义类型）
传递参数：参数替换分两种：#{id} => 预处理语句的？ || '${id}' => 直接替换为变量
-----------------------------------
test.javapublic static void main(String[] args) {
SqlSessionFactory sqlSessionFactory;
SqlSession session = null;
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
session = sqlSessionFactory.openSession();
HashMap<String,String> result = session.selectOne("selectBlog", 110);
System.out.println("Result: " result);
} catch (Exception ex) {
ex.printStackTrace();
} finally {
if(session != null){
session.close();
}
}
}session.selectOne是session自带方法（selectList可以获取多条数据），传入的第一个字符串就是之前定义的id，第二个参数是传入的参数(多个参数可以使用一个HashMap来传参)。
5.简单抽象方法：mybatis-config.xml mapper.xml interface.java test.java
mybatis-config.xml
代码语言：javascript复制<package name="com.mybatis.manager.mapper"/>mapper.xml
代码语言：javascript复制<mapper namespace="com.mybatis.manager.mapper.ReleaseDTOMapper">
<select id="getReleaseNote" parameterType="map" resultType="map">
SELECT rn.* FROM GPCM_RELEASE_NOTE rn where rn.state = #{STATE} and rn.upgrade_id = #{UPGRADE_ID}
</select>
<select id="getUpgradeNote" parameterType="map" resultType="map">
SELECT un.* FROM GPCM_UPGRADE_NOTE un
</select>
</mapper>interface.java
代码语言：javascript复制public interface ReleaseDTOMapper {
public HashMap<String,String> getReleaseNote(HashMap<String,String> param);
public ArrayList<HashMap<String,String>> getUpgradeNote();
}test.java
代码语言：javascript复制public static void main(String[] args) {
SqlSessionFactory sqlSessionFactory;
SqlSession session = null;
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
session = sqlSessionFactory.openSession();
ReleaseDTOMapper mapper = session.getMapper(ReleaseDTOMapper.class);
HashMap<String,String> param = new HashMap<String,String>();
param.put("STATE", "N");
param.put("UPGRADE_ID","2");
HashMap<String,String> result = mapper.getReleaseNote(param);
System.out.println("Result: " result);
List<HashMap<String,String>> rs = mapper.getUpgradeNote();
for(HashMap<String,String> r : rs){
System.out.println("Result: " r);
}
} catch (Exception ex) {
ex.printStackTrace();
} finally {
if(session != null){
session.close();
}
}
}6.通用方法：使用自定义数据类型映射参数和结果集
mapper.xml
代码语言：javascript复制<?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.mybatis.manager.mapper.ReleaseDTOMapper">
<resultMap id="BaseResultMap" type="com.mybatis.manager.persist.ReleaseNoteDTO" >
<result column="RELEASE_ID" property="releaseId" jdbcType="INTEGER" />
<result column="RELEASE_NAME" property="releaseName" jdbcType="VARCHAR" />
<result column="RELEASE_DESC" property="releaseDesc" jdbcType="VARCHAR" />
<result column="UPGRADE_ID" property="upgradeId" jdbcType="INTEGER" />
<result column="STATE" property="state" jdbcType="VARCHAR" />
<result column="CREATE_DATE" property="createDate" jdbcType="TIMESTAMP" />
<result column="MOD_DATE" property="modDate" jdbcType="TIMESTAMP" />
<result column="UPGRADE_DATE" property="upgradeDate" jdbcType="TIMESTAMP" />
</resultMap>
<select id="getReleaseNote" parameterType="com.mybatis.manager.persist.ReleaseNoteDTO" resultMap="BaseResultMap">
SELECT rn.* FROM GPCM_RELEASE_NOTE rn where rn.state = #{state,jdbcType=VARCHAR} and rn.upgrade_id = #{upgradeId,jdbcType=INTEGER}
</select>
</mapper>注意resultType -> resultMap，列与java对象的参数必需要对应，否则获取的结果就是null。
传入的参数为一个是可以定义parameterType="java.lang.Integer"，多个参数必需合为一个对象传输，如Map或自定义Dto。
可以使用多表查询，将结果集传入一个自定义Dto中，结果集绑定如下：
<resultMap id = "Upgrade" type="com.mybatis.manager.persist.UpgradeNoteDto"> <result column="UPGRADE_ID" property="upgradeId" jdbcType="INTEGER" /> <result column="UPGRADE_NAME" property="upgradeName" jdbcType="VARCHAR" /> </resultMap> <resultMap id="BaseResultMap" type="com.mybatis.manager.persist.ReleaseNoteDto" > <result column="RELEASE_ID" property="releaseId" jdbcType="INTEGER" /> <result column="RELEASE_NAME" property="releaseName" jdbcType="VARCHAR" /> <result column="RELEASE_DESC" property="releaseDesc" jdbcType="VARCHAR" /> <association property = "upgrade" javaType="com.mybatis.manager.persist.UpgradeNoteDto" resultMap = "Upgrade"/> </resultMap> property = "upgrade"在Dto中定义为 private UpgradeNoteDto upgrade;
ReleaseNoteDTO.java 自定义数据模型
代码语言：javascript复制public class ReleaseNoteDTO {
private Integer releaseId;
private String releaseName;
private String releaseDesc;
private Integer upgradeId;
private String state;
private Date createDate;
private Date modDate;
private Date upgradeDate;
/*******************
*GETTER/SETTER
*******************/
}interface.java
代码语言：javascript复制public interface ReleaseNoteDtoMapper {
public ReleaseNoteDto getReleaseNote(ReleaseNoteDto param);
}test.java
代码语言：javascript复制ReleaseNoteDTO param = new ReleaseNoteDTO();
param.setState("N");
param.setUpgradeId(2);
ReleaseNoteDTO result = mapper.getReleaseNote(param);
System.out.println("Result: " result.getReleaseDesc());7.基本应用的结构参考
附录：相关参考资料
官网中文教程 http://www.mybatis.org/mybatis-3/zh/getting-started.html
