Mybatis入门学习

INSERT INTO `message` VALUES (1, ‘查看‘, ‘精彩内容‘, ‘精彩内容‘);
INSERT INTO `message` VALUES (2, ‘段子‘, ‘精彩段子‘, ‘如果你的月薪是3000块钱，请记得分成五份，一份用来买书，一份给家人，一份给女朋友买化妆品和衣服，一份请朋友们吃饭，一份作为同事的各种婚丧嫁娶的份子钱。剩下的2999块钱藏起来，不要告诉任何人‘);
INSERT INTO `message` VALUES (3, ‘新闻‘, ‘今日头条‘, ‘7月17日，马来西亚一架载有298人的777客机在乌克兰靠近俄罗斯边界坠毁。另据国际文传电讯社消息，坠毁机型为一架波音777客机，机载约280名乘客和15个机组人员。\r\n乌克兰空管部门随后证实马航MH17航班坠毁。乌克兰内政部幕僚表示，这一航班在顿涅茨克地区上空被击落。马来西亚航空公司确认，该公司从阿姆斯特丹飞往吉隆坡的MH17航班失联，并称最后与该客机取得联系的地点在乌克兰上空。图为马航客机坠毁现场。‘);
INSERT INTO `message` VALUES (4, ‘娱乐‘, ‘娱乐新闻‘, ‘昨日，邓超在微博分享了自己和孙俪的书法。夫妻同样写幸福，但差距很大。邓超自己都忍不住感慨字丑：左边媳妇写的。右边是我写的。看完我再也不幸福了。‘);
INSERT INTO `message` VALUES (5, ‘电影‘, ‘近日上映大片‘, ‘《忍者神龟》[2]真人电影由美国派拉蒙影业发行，《洛杉矶之战》导演乔纳森·里贝斯曼执导。 \r\n片中四只神龟和老鼠老师都基于漫画和卡通重新绘制，由动作捕捉技术实现。\r\n其中皮特·普劳泽克饰演达芬奇(武器：武士刀)，诺尔·费舍饰演米开朗基罗(武器：双节棍)，阿伦·瑞奇森饰演拉斐尔(武器：铁叉)，杰瑞米·霍华德饰演多拉泰罗(武器：武士棍)。\r\n该片计划于2014年8月8日在北美上映。‘);
INSERT INTO `message` VALUES (6, ‘彩票‘, ‘中奖号码‘, ‘查啥呀查，你不会中奖的！‘);

public class Message {
    private int id;
    private String command;
    private String description;
    private String content;
    
    public Message(){}

    public int getId() {
        return id;
    }

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

    public String getCommand() {
        return command;
    }

    public void setCommand(String command) {
        this.command = command;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

<?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>
  <!-- <settings>
    <setting name="useGeneratedKeys" value="false"/>
    <setting name="useColumnLabel" value="true"/>
  </settings>

  <typeAliases>
    <typeAlias alias="UserAlias" type="org.apache.ibatis.submitted.complex_property.User"/>
  </typeAliases> -->

  <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://127.0.0.1:3306/test_mybatis"/>
        <property name="username" value="root"/>
        <property name="password" value="21henearkrxnrn!@#$"/>
      </dataSource>
    </environment>
  </environments>

  <mappers>
    <mapper resource="config/sqlxml/Message.xml"/>
  </mappers>

</configuration>

<?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="javabean.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="getByName" resultMap="MessageResult">
    select id,command,description,content from message where 1=1 
  </select>

</mapper>

public class DBUtil {
    public SqlSession getSqlSession() throws IOException{
        //通过配置文件Configuration.xml获取数据库连接信息
        Reader reader = Resources.getResourceAsReader("config/Configuration.xml");
        //通过配置信息构建一个SqlSessionFactory
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        //通过sqlSessionFactory打开一个数据库会话
        SqlSession sqlSession = sqlSessionFactory.openSession();
        return sqlSession;
    }
}

public class MessageDAO {
    /**
     * 查询列表信息（方法名是为多选择查询起的，会在以后的文章中实现）
     */
    public List<Message> getByName(String command, String description){
        DBUtil dbUtil = new DBUtil();
        SqlSession sqlSession = null;
        List<Message> messageList = new ArrayList<Message>();
        try {
            sqlSession = dbUtil.getSqlSession();
            //通过sqlSession执行SQL语句，需要sql的配置文件Message.xml
            messageList = sqlSession.selectList("Message.getByName");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            if(sqlSession!=null){
                sqlSession.close();
            }
        }
        return messageList;
    }
    
}

@SuppressWarnings("serial")
public class ListServlet extends HttpServlet{
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //编码一律用utf-8
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        
        //接收页面参数的值
        String command = req.getParameter("command");
        String description = req.getParameter("description");
        /*一开始总打印null，原来是name放错位置了，应该放到input里！！！
        System.out.println(command);
        System.out.println(description);*/
        
        //按command和description查询列表信息
        MessageDAO messageDAO = new MessageDAO();
        List<Message> messageList = messageDAO.getByName(command, description);
        
        //向页面传值
        req.setAttribute("command", command);
        req.setAttribute("description", description);
        req.setAttribute("messageList", messageList);
        
        //页面跳转
        /*因为要传递参数，而不用重定向*/
        req.getRequestDispatcher("/jsp/back/list.jsp").forward(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>testMybatis</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  
  <servlet>
      <servlet-name>ListServlet</servlet-name>
      <servlet-class>servlet.ListServlet</servlet-class>
  </servlet>
  <servlet-mapping>
      <servlet-name>ListServlet</servlet-name>
      <url-pattern>/list.action</url-pattern>
  </servlet-mapping>
</web-app>

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <base href="<%=basePath%>">
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
        <meta http-equiv="X-UA-Compatible"content="IE=9; IE=8; IE=7; IE=EDGE" />
        <title>内容列表页面</title>
        <link href="css/all.css" rel="stylesheet" type="text/css" />
    </head>
    <body style="background: #e1e9eb;">
        <form action="list.action" id="mainForm" method="post">
            <div class="right">
                <div class="current">当前位置：<a href="javascript:void(0)" style="color:#6E6E6E;">内容管理</a> &gt; 内容列表</div>
                <div class="rightCont">
                    <p class="g_title fix">内容列表 <a class="btn03" href="#">新 增</a>&nbsp;&nbsp;&nbsp;&nbsp;<a class="btn03" href="#">删 除</a></p>
                    <table class="tab1">
                        <tbody>
                            <tr>
                                <td width="90" align="right">指令名称：</td>
                                <td>
                                    <input name="command" type="text" class="allInput" value="${command}"/>
                                </td>
                                <td width="90" align="right">描述：</td>
                                <td>
                                    <input name="description" type="text" class="allInput" value="${description}"/>
                                </td>
                                <td width="85" align="right"><input type="submit" class="tabSub" value="查 询" /></td>
                               </tr>
                        </tbody>
                    </table>
                    <div class="zixun fix">
                        <table class="tab2" width="100%">
                            <tbody>
                                <tr>
                                    <th><input type="checkbox" id="all" onclick="#"/></th>
                                    <th>序号</th>
                                    <th>指令名称</th>
                                    <th>描述</th>
                                    <th>操作</th>
                                </tr>
                                <c:forEach items="${messageList}" var="message" varStatus="status">
                                    <tr <c:if test="${status.index % 2 !=0}">style="background-color:#ECF6EE;"</c:if>>
                                        <td><input type="checkbox" /></td>
                                        <td>${status.index + 1}</td>
                                        <td>${message.command }</td>
                                        <td>${message.description }</td>
                                        <td>
                                            <a href="#">修改</a>&nbsp;&nbsp;&nbsp;
                                            <a href="#">删除</a>
                                        </td>
                                    </tr>
                                </c:forEach>
                            </tbody>
                        </table>
                        <div class=‘page fix‘>
                            共 <b>4</b> 条
                            <a href=‘###‘ class=‘first‘>首页</a>
                            <a href=‘###‘ class=‘pre‘>上一页</a>
                            当前第<span>1/1</span>页
                            <a href=‘###‘ class=‘next‘>下一页</a>
                            <a href=‘###‘ class=‘last‘>末页</a>
                            跳至&nbsp;<input type=‘text‘ value=‘1‘ class=‘allInput w28‘ />&nbsp;页&nbsp;
                            <a href=‘###‘ class=‘go‘>GO</a>
                        </div>
                    </div>
                </div>
            </div>
        </form>
    </body>
</html>