下载网站:
https://github.com/mybatis/mybatis-3/releases
1. 引入 web 项目下引入 mybatis.jar
引入到 WebRoot/WEB-INF/lib 下
2. 配置 mybatis 核心配置文件 (这个在 mybatis 源码包中)
mybatis-3-mybatis-3.4.5\src\test\java\org\apache\ibatis\submitted\complex_property\Configuration.xml
将 Configuration.xml 复制到 web 项目中
配置核心配置文件
- <configuration>
- <environments default="development">
- <environment id="development">
- <transactionManager type="JDBC">
- <property name="" value="" />
- </transactionManager>
- <dataSource type="UNPOOLED">
- <property name="driver" value="com.mysql.jdbc.Driver" />
- <property name="url" value="jdbc:mysql://localhost:3306/micro_message"
- />
- <property name="username" value="root" />
- <property name="password" value="123456" />
- </dataSource>
- </environment>
- </environments>
- <mappers>
- <mapper resource="com/daoan/config/sqlxml/Message.xml" />
- </mappers>
- </configuration>
3. 得到 sqlSession 对象
- 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;
- /**
- * 访问数据库类
- */
- public class DBAccess {
- public SqlSession getSqlSession() throws IOException {
- // 通过配置文件获取数据库连接信息
- Reader reader = Resources.getResourceAsReader("com/daoan/config/Configuration.xml");
- // 通过配置信息构建 SqlSessionFactoy
- SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
- // 通过 SqlSessionFactoy 打开一个数据库会话
- SqlSession sqlSession = sqlSessionFactory.openSession();
- return sqlSession;
- }
- }
4. 使用 Mybatis 框架来连接连接 sql 以及执行 sql 语句
- /**
- * 和 Message 表相关的数据库操作
- */
- public class MessageDao {
- /**
- * 根据查询条件, 查询消息列表
- */
- public List < Message > queryMessageList(String command, String description) {
- DBAccess dbAccess = new DBAccess();
- List < Message > messageList = new ArrayList < Message > ();
- SqlSession sqlSession = null;
- try {
- sqlSession = dbAccess.getSqlSession();
- // 通过 sqlSession 执行 SQL 语句
- messageList = sqlSession.selectList("Message.queryMessageList");
- } catch(IOException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } finally {
- if (sqlSession != null) {
- sqlSession.close();
- sqlSession = null;
- }
- }
- return messageList;
- }
- public static void main(String[] args) {
- MessageDao messageDao = new MessageDao();
- messageDao.queryMessageList("", "");
- }
- }
5.Message.xml 配置文件 (取出数据库某个字段的值放在 java 的对象的属性里面)
- <?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="Message">
- <resultMap type="com.daoan.bean.Message" id="MessageResult">
- <id column="Id" jdbcType="INTEGER" property="id" />
- <result column="Command" jdbcType="VARCHAR" property="command" />
- <result column="Description" jdbcType="VARCHAR" property="description"
- />
- <result column="Context" jdbcType="VARCHAR" property="context" />
- </resultMap>
- <select id="queryMessageList" resultMap="MessageResult">
- select Id,Command,Description,Context from message where 1=1
- </select>
- </mapper>
来源: http://www.bubuko.com/infodetail-2498664.html