mybatis模板
因为这里是说mybatis的,所以呢 servlet就不做多说了,代码也不在这里贴出来了.
log4j.properties
log4j.rootLogger=DEBUG,Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n
log4j.logger.org.apache=INFO
mybatis-config.xml
<?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>
<!-- 注意：一定要加在<properties>之后且<typeAliases>之前 -->
<settings>
<setting name="logImpl" value="LOG4J" />
</settings>
<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://127.0.0.1:3306/micro_message" /> <property name="username" value="root" /> <property name="password" value="gys" /> </dataSource> </environment> </environments> <mappers> <mapper resource="com/imooc/config/sqlxml/message.xml" /> </mappers> </configuration>
message.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="message"> <resultMap type="com.imooc.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="CONTENT" jdbcType="VARCHAR" property="content" /> </resultMap> <select id="queryMessageList" parameterType="com.imooc.bean.Message" resultMap="MessageResult"> select ID,COMMAND,DESCRIPTION,CONTENT from message <where> <!--以下条件 test="command != null && "".equals(command.trim()) " --> <!-- <if test="command !=null && !"".equals(command.trim())"> and COMMAND =#{command} </if> --> <if test="command != null and !"".equals(command.trim())"> and command=#{command} </if> <if test="description != null and !"".equals(description.trim())"> and description like '%' #{description} '%' </if> </where> </select> <!-- 单个删除 ,这种情况 参数用_parameter --> <delete id="deleteOne" parameterType="int"> delete from message where ID=#{_parameter} </delete> <!-- 批量删除 --> <delete id="deleteBatch" parameterType="java.util.List"> delete from message where ID in ( <foreach collection="list" item="item" separator=","> #{item} </foreach> ) </delete> <!-- 这里的keyProperty对应的是类中的属性,不是数据库中的字段,插入数据返回id主键值 --> <insert id="insertData" parameterType="com.imooc.bean.Message" useGeneratedKeys="true" keyProperty="id"> insert into message (COMMAND,DESCRIPTION,CONTENT) values (#{command},#{description},#{content}) </insert> <select id="getDataByCommand" parameterType="String" resultMap="MessageResult" resultType="com.imooc.bean.Message"> select ID,COMMAND,DESCRIPTION,CONTENT from message where COMMAND=#{_parameter} limit 1 </select> </mapper>
DBAccess.java
package com.imooc.db; 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 * @author gys * */ 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/imooc/config/mybatis-config.xml"); //通过配置信息构建一个SqlSessionFactory SqlSessionFactory sqlSessionFactory=new SqlSessionFactoryBuilder().build(reader); //通过sqlSessionFactory打开一个数据库回话 SqlSession sqlSession=sqlSessionFactory.openSession(); return sqlSession; } }
MessageDao.java
package com.imooc.dao; import java.io.IOException; import java.util.ArrayList; import java.util.List; import org.apache.ibatis.session.SqlSession; import com.imooc.bean.Message; import com.imooc.db.DBAccess; /** * 和message表相关的数据库操作 * @author gys * */ public class MessageDao { public List<Message> queryMessageList(String command,String description){ List<Message> messageList=new ArrayList<Message>(); DBAccess dbAccess=new DBAccess(); SqlSession sqlSession=null; try { sqlSession= dbAccess.getSqlSession(); Message message=new Message(); message.setCommand(command); message.setDescription(description); //通过sqlSession执行sql语句 messageList=sqlSession.selectList("message.queryMessageList",message); } catch (IOException e) { e.printStackTrace(); }finally{ if(sqlSession !=null){ sqlSession.close(); } } return messageList; } /** * 单条删除 * @param id */ public void deleteOne(int id){ DBAccess dbAccess=new DBAccess(); SqlSession sqlSession=null; try { sqlSession= dbAccess.getSqlSession(); //通过sqlSession执行sql语句 int count=sqlSession.delete("message.deleteOne",id); sqlSession.commit(); } catch (IOException e) { e.printStackTrace(); }finally{ if(sqlSession !=null){ sqlSession.close(); } } } /** * 批量删除 */ public void deleteBatch(List<Integer> ids){ DBAccess dbAccess=new DBAccess(); SqlSession sqlSession=null; try { sqlSession= dbAccess.getSqlSession(); //通过sqlSession执行sql语句 int count=sqlSession.delete("message.deleteBatch",ids); sqlSession.commit(); } catch (IOException e) { e.printStackTrace(); }finally{ if(sqlSession !=null){ sqlSession.close(); } } } /** * 插入数据,获取主键 */ public int insertData(Message message){ DBAccess dbAccess=new DBAccess(); SqlSession sqlSession=null; int id=0; try { sqlSession= dbAccess.getSqlSession(); //通过sqlSession执行sql语句 int count=sqlSession.insert("message.insertData",message);//返回受影响的行数 sqlSession.commit(); } catch (IOException e) { e.printStackTrace(); }finally{ if(sqlSession !=null){ sqlSession.close(); } } id=message.getId(); return id;//返回插入数据的id } /** * 获取单个数据 */ public Message getDataByCommand(String command){ DBAccess dbAccess=new DBAccess(); SqlSession sqlSession=null; Message message=null; try { sqlSession= dbAccess.getSqlSession(); //通过sqlSession执行sql语句 message=sqlSession.selectOne("message.getDataByCommand",command);//返回受影响的行数 sqlSession.commit(); } catch (IOException e) { e.printStackTrace(); }finally{ if(sqlSession !=null){ sqlSession.close(); } } return message;//返回插入数据的id } }
MessageService.java
package com.imooc.service; import java.util.ArrayList; import java.util.List; import com.imooc.bean.Message; import com.imooc.dao.MessageDao; public class MessageService { public List<Message> queryMessageList(String command,String description){ MessageDao messageDao=new MessageDao(); return messageDao.queryMessageList(command, description); } //单条删除 public void deleteOne(String id){ if(id!=null && !"".equals(id.trim())){ MessageDao messageDao=new MessageDao(); messageDao.deleteOne(Integer.valueOf(id)); } } /** * 批量删除 */ public void deleteBatch(String[] ids){ MessageDao messageDao=new MessageDao(); List<Integer> list=new ArrayList<Integer>(); if(ids==null){ System.out.println("请选择删除的项目!"); }else{ for(String id:ids){ list.add(Integer.valueOf(id)); } messageDao.deleteBatch(list); } } /** * 批量删除 */ public int insertData(Message message){ MessageDao messageDao=new MessageDao(); int id=messageDao.insertData(message); return id; } /** * 获取单个数据 */ public Message getDataByCommand(String command){ MessageDao messageDao=new MessageDao(); return messageDao.getDataByCommand(command); } }
这些就是mybatis最基础的模板代码.供以后查找用
