java.jpg

第一章 案例簡(jiǎn)介

設(shè)計(jì)類(lèi)似微信公眾號(hào)的自動(dòng)回復(fù)功能

準(zhǔn)備工作
JSP JSTL EL JS/JQUERY
Servlet JavaBean
JDBC MySQL

第二章 實(shí)戰(zhàn)第一部--黎明前的黑暗

2.1 黎明前的黑暗

案例分析

基本功能 :接受發(fā)送指令 根據(jù)指令自動(dòng)回復(fù)對(duì)應(yīng)的內(nèi)容

模塊劃分 :

• 回復(fù)內(nèi)容維護(hù)
• 對(duì)話功能
• 回復(fù)內(nèi)容列表
• 回復(fù)內(nèi)容刪除

2.2 案例演示

2.3 頁(yè)面跳轉(zhuǎn)

2.4 連接數(shù)據(jù)庫(kù)

2.5 數(shù)據(jù)展示

第三章 實(shí)戰(zhàn)第二部--Mybatis來(lái)襲

3.1 Mybatis的下載并搭建核心架構(gòu)

https://github.com/mybatis/mybatis-3/releases下載Mybatis jar包及源碼包

**演示代碼中的配置文件的詳細(xì)路徑 : **
src/test/java/org/apache/ibatis/submitted/complex_property/Configuration.xml

復(fù)制到項(xiàng)目的src/com/qezhhnjy/config/Configuration.xml

Mybatis的相關(guān)知識(shí)

Dao的需求

1. 對(duì)象能與數(shù)據(jù)庫(kù)交互
2. 能執(zhí)行SQL語(yǔ)句

Mybatis中提供給Dao層的處理對(duì)象為SqlSession

SqlSession的作用 :

1. 向SQL語(yǔ)句傳入?yún)?shù)
2. 執(zhí)行SQL語(yǔ)句
3. 獲取執(zhí)行SQL 語(yǔ)句的結(jié)果
4. 事務(wù)的控制

如何獲得SqlSession :
1. 通過(guò)配置文件獲取數(shù)據(jù)庫(kù)連接相關(guān)信息
com.qezhhnjy.config.Configuration.xml

<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://localhost:3306/micro_message?useSSL=false"/>
        <property name="username" value="root"/>
        <property name="password" value="root" />
<!--property標(biāo)簽對(duì)應(yīng)本機(jī)數(shù)據(jù)庫(kù)連接相關(guān)信息-->
      </dataSource>
    </environment>
  </environments>

  <mappers>
    <mapper resource="com/qezhhnjy/config/sqlxml/Message.xml"/>
<!--mapper標(biāo)簽為配置好的各個(gè)實(shí)體類(lèi)與數(shù)據(jù)表映射xml文件位置-->
  </mappers>
</configuration>

2. 通過(guò)配置信息構(gòu)建SqlSessionFactory
com.qezhhnjy.db.DBAccess.getSession();

public class DBAccess {
    public SqlSession getSqlSession() throws IOException {
        //通過(guò)配置文件獲取數(shù)據(jù)庫(kù)連接信息
        Reader reader = Resources.getResourceAsReader("com/qezhhnjy/config/Configuration.xml");
        //通過(guò)配置信息構(gòu)建一個(gè)SqlSessionFactory
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(reader);
        return ssf.openSession();
    }
}

3. 通過(guò)SqlSessionFactory打開(kāi)數(shù)據(jù)庫(kù)會(huì)話
com.qezhhnjy.dao.MessageListDao.mybatisQuery(...);

    public static List<Message> mybatisQuery(String command,String description){
        DBAccess dbAccess = new DBAccess();
        List<Message> messageList = new ArrayList<>();
        SqlSession sqlSession = null;
        try {
            sqlSession = dbAccess.getSqlSession();
            messageList = sqlSession.selectList("Message.find");
            //Message對(duì)應(yīng)message.xml中mapper的屬性namespace
            //find對(duì)應(yīng)message.xml中select標(biāo)簽的id
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(sqlSession !=null)sqlSession.close();
        }
        return messageList;
    }

3.2 SQL基本配置與執(zhí)行

src/test/java/org/apache/ibatis/submitted/complex_property/User.xml
將該文件復(fù)制到項(xiàng)目的
src/com/qezhhnjy/config/sqlxml/Message.xml

<mapper namespace="Message">
  <!--由于項(xiàng)目中所有select標(biāo)簽的id都不能重名.
  為了加以區(qū)分, 使用namespace屬性來(lái)設(shè)置,不同namespace下的id可以相同.
  類(lèi)似java中包的定義及使用-->

  <resultMap type="UserAlias" id="UserResult">
    <id column="id" jdbcType="INTEGER" property="id"/>//主鍵
    <result column="username" jdbcType="VARCHAR" property="username"/>
<!--column對(duì)應(yīng)數(shù)據(jù)表列名  property對(duì)應(yīng)實(shí)體類(lèi)屬性名  jdbcType對(duì)應(yīng)java.sql.Types類(lèi)中的常量名-->
    <result column="password" jdbcType="VARCHAR" property="password.encrypted"/>
    <result column="administrator" jdbcType="BOOLEAN" property="administrator"/>
  </resultMap>

  <select id="find" parameterType="long" resultMap="UserResult">
    SELECT * FROM user WHERE id = #{id:INTEGER}
  </select>
<!--原文檔中有多個(gè)功能各異的select查詢標(biāo)簽-->
</mapper>

Message類(lèi)對(duì)應(yīng)的全查詢語(yǔ)句和實(shí)體類(lèi)映射

  <resultMap type="com.qezhhnjy.bean.Message" id="MessageResult">
    <id column="id" jdbcType="VARCHAR" 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="find" resultMap="MessageResult">
    SELECT id,command,description,content FROM MESSAGE WHERE 1=1 
  </select>

第四章 實(shí)戰(zhàn)第三部

4.1 動(dòng)態(tài)SQL拼接

OGNL是一個(gè)強(qiáng)大的表達(dá)式語(yǔ)言
OGNL表達(dá)式語(yǔ)言詳解
http://blog.csdn.net/yu102655/article/details/52179695
http://blog.csdn.net/hello_xusir/article/details/53423399

Paste_Image.png

Paste_Image.png

配置SQL拼接實(shí)現(xiàn)字段查詢和模糊查詢

1. 將用戶輸入的查詢內(nèi)容封裝并傳遞給mybatis
com.qezhhnjy.dao.MessageListDao.mybatisQuery(...);

...
Message temp = new Message();
temp.setCommand(command);
temp.setDescription(description);
 try {
      sqlSession = dbAccess.getSqlSession();
      messageList = sqlSession.selectList("Message.find",temp);
...
//只截取了與全查詢不同的部分. 通過(guò)封裝對(duì)應(yīng)屬性的輸入值到實(shí)體類(lèi), 然后傳遞給mybatis,之后配置Message.xml來(lái)映射對(duì)應(yīng)屬性到sql語(yǔ)句中.

2. 完善配置Message.xml
Message.xml

  <select id="find" parameterType="com.qezhhnjy.bean.Message" resultMap="MessageResult">
      //parameterType屬性即表示傳遞進(jìn)來(lái)的對(duì)象類(lèi)型
      SELECT id,command,description,content FROM MESSAGE WHERE 1=1
      <if test="command != null && !"".equals(command.trim())">
           AND command = #{command}
      </if>
      <!--if標(biāo)簽test屬性為OGNL語(yǔ)言, 可以識(shí)別java屬性及方法,但是""和&(&)要進(jìn)行轉(zhuǎn)義,&&也可以使用and 關(guān)鍵字代替.
      if標(biāo)簽內(nèi)容為銜接前面的sql語(yǔ)句, 為mybatis來(lái)識(shí)別,且不必刻意空格來(lái)避免錯(cuò)誤.-->
      <if test="description != null and !"".equals(description.trim())">
           AND description LIKE '%' #{description} '%'
      </if>
      <!--模糊查詢的寫(xiě)法容易出現(xiàn)錯(cuò)誤,%前后要加上'',并且#{...}前后仍然要注意空格-->
  </select>

4.2 應(yīng)用log4j調(diào)試動(dòng)態(tài)SQL

在官網(wǎng)下載的mybatis文件目錄下有l(wèi)og4j的jar包
Mybatis 3.4.4/mybatis-3.4.4/lib/log4j-1.2.17.jar
log4j的配置文件: log4j.properties(mybatis源碼包)
Mybatis 3.4.4/mybatis-3-mybatis-3.4.4/src/test/java/log4j.properties

配置文件默認(rèn)加載到src/根目錄下.

### Global logging configuration
log4j.rootLogger=ERROR, stdout
//配置日志輸出級(jí)別和位置,級(jí)別(debug<info<warn<error),如果設(shè)置為INFO,則會(huì)輸出info,warn,error的信息,如此.
### Uncomment for MyBatis logging
log4j.logger.org.apache=INFO
### 將org.apache包的日志輸出級(jí)別單獨(dú)設(shè)置為INFO,也可以再單獨(dú)設(shè)置輸出位置.

### Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d %5p [%t] - %m%n
### 格式化輸出, %d表示當(dāng)前時(shí)間, %p(priority)輸出優(yōu)先級(jí),%t表示當(dāng)前線程,  %m表示具體信息, %n換行.

在mybatis的org.apache.ibatis.logging.jdbc包中,有jdbc各大類(lèi)對(duì)象對(duì)應(yīng)的日志輸出類(lèi).
org.apache.ibatis.logging.jdbc.CollectionLogger類(lèi)的源碼

public final class ConnectionLogger extends BaseJdbcLogger implements InvocationHandler {
    private Connection connection;

    private ConnectionLogger(Connection conn, Log statementLog, int queryStack) {
        super(statementLog, queryStack);
        this.connection = conn;
    }

    public Object invoke(Object proxy, Method method, Object[] params) throws Throwable {
        try {
            if(Object.class.equals(method.getDeclaringClass())) {
                return method.invoke(this, params);
            } else {
                PreparedStatement stmt;
                if("prepareStatement".equals(method.getName())) {
                    if(this.isDebugEnabled()) {
                        this.debug(" Preparing: " + this.removeBreakingWhitespace((String)params[0]), true);
                    }

                    stmt = (PreparedStatement)method.invoke(this.connection, params);
                    stmt = PreparedStatementLogger.newInstance(stmt, this.statementLog, this.queryStack);
                    return stmt;
                } else if("prepareCall".equals(method.getName())) {
                    if(this.isDebugEnabled()) {
                        this.debug(" Preparing: " + this.removeBreakingWhitespace((String)params[0]), true);
                    }

                    stmt = (PreparedStatement)method.invoke(this.connection, params);
                    stmt = PreparedStatementLogger.newInstance(stmt, this.statementLog, this.queryStack);
                    return stmt;
                } else if("createStatement".equals(method.getName())) {
                    Statement stmt = (Statement)method.invoke(this.connection, params);
                    stmt = StatementLogger.newInstance(stmt, this.statementLog, this.queryStack);
                    return stmt;
                } else {
                    return method.invoke(this.connection, params);
                }
            }
        } catch (Throwable var5) {
            throw ExceptionUtil.unwrapThrowable(var5);
        }
    }

    public static Connection newInstance(Connection conn, Log statementLog, int queryStack) {
        InvocationHandler handler = new ConnectionLogger(conn, statementLog, queryStack);
        ClassLoader cl = Connection.class.getClassLoader();
        return (Connection)Proxy.newProxyInstance(cl, new Class[]{Connection.class}, handler);
    }

    public Connection getConnection() {
        return this.connection;
    }
}

調(diào)試階段設(shè)置為DEBUG級(jí)別, 可以輸出最多的信息

4.3 實(shí)現(xiàn)單條信息刪除

1. 配置Message.xml

    <delete id="deleteOne" parameterType="int" >
        DELETE FROM message WHERE id = #{_parameter}
<!--String及基本類(lèi)型用_parameter代替, 類(lèi)似OGNL-->
    </delete>

**2. 設(shè)計(jì)Dao層方法 **MessageListDao.mybatisDeleteOne(int);

    public static void mybatisDeleteOne(int id){
        DBAccess dbAccess = new DBAccess();
        SqlSession sqlSession = null;
        try {
            sqlSession = dbAccess.getSqlSession();
            sqlSession.delete("Message.deleteOne", id);
            sqlSession.commit();
            //mybatis對(duì)數(shù)據(jù)庫(kù)增刪改需要手動(dòng)提交
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(sqlSession !=null)sqlSession.close();
        }
    }

3. Message維護(hù)類(lèi)Service中的邏輯方法MessageMaintainService.deletOne(String);

    public static void deleteOne(String id) {
//service層中主要處理類(lèi)似的參數(shù)邏輯問(wèn)題
        if (id != null &&!"".equals(id.trim())) {
           MessageListDao.mybatisDeleteOne(Integer.parseInt(id));
        }
    }

4. 設(shè)計(jì)Servlet類(lèi)servlet.DeleteOneServlet

@WebServlet(name = "DeleteOneServlet",value = "/deleteone.action")
public class DeleteOneServlet extends HttpServlet {
    private static final long serialVersionUID = -1163248074005443694L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //設(shè)置編碼
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        String id = request.getParameter("id");
        System.out.println(id);
        //數(shù)據(jù)庫(kù)查詢
        //servlet中盡量不要設(shè)計(jì)對(duì)數(shù)據(jù)為null及類(lèi)型錯(cuò)誤==的判定,在service中進(jìn)行.
        MessageMaintainService.deleteOne(id);
        //跳轉(zhuǎn)
        System.out.println("刪除成功-----");
        request.getRequestDispatcher("/list.action").forward(request, response);
    //跳轉(zhuǎn)不能直接跳轉(zhuǎn)到list.jsp頁(yè)面.
    //因?yàn)樘D(zhuǎn)的request并沒(méi)有添加messageList屬性,jsp中邏輯語(yǔ)言會(huì)出現(xiàn)空指針.
    //要重新跳轉(zhuǎn)到ListServlet重新查詢數(shù)據(jù)再跳轉(zhuǎn)到實(shí)際頁(yè)面.
    }
}

5. 編寫(xiě)list.jsp中刪除鏈接的href

<a href="${basePath}deleteone.action?id=<%=message.getId()%>">刪除</a>

比較簡(jiǎn)單的方法是通過(guò)get方法傳值.但這種方法容易泄漏信息, 且只能傳遞少量信息.
在類(lèi)似查詢指定內(nèi)容或模糊內(nèi)容數(shù)據(jù)后進(jìn)行單條刪除時(shí), 由于無(wú)法傳遞查詢輸入框中的值. 每次刪除后會(huì)刷新為空并顯示全部條數(shù)據(jù),影響用戶體驗(yàn).

這時(shí)可以使用js設(shè)置為post方法傳遞信息.

<a href="javascript:(function(id) {
      document.getElementById('deleteOneId').value = id;
      var form=document.getElementById('mainForm');
     form.action='${pageContext.request.contextPath}/deleteOne.action';
    form.submit(); }) ('<%=message2.getId()%>')" >刪除</a>
  <!--第二個(gè)括號(hào)里面的jsp代碼要加上' '.這里由于代碼的輸出是數(shù)字, 不加也不會(huì)出錯(cuò).但其他時(shí)候則會(huì)導(dǎo)致出錯(cuò), 且沒(méi)有報(bào)錯(cuò), 很難被發(fā)現(xiàn)!!-->

同時(shí)在table循環(huán)輸出message以外設(shè)置一個(gè)隱藏標(biāo)簽:

<input type="hidden" name="messageId" id="deleteOneId" value="" />

4.4 實(shí)現(xiàn)信息批量刪除

1. 配置Message.xml

    <delete id="deleteBatch" parameterType="java.util.List" >
        DELETE FROM message WHERE ID in(
        <foreach  collection="list" item="item" separator=",">
            #{item}
        </foreach>
<!--foreach實(shí)現(xiàn)將接收到的list對(duì)象遍歷出來(lái), 并且用separator內(nèi)的符號(hào)進(jìn)行分隔-->
        )
    </delete>

2. 設(shè)計(jì)Dao層方法 MessageListDao.mybatisDeleteBatch(List idList);
3. Message維護(hù)類(lèi)Service中的邏輯方法MessageMaintainService.deletBatch(String[] ids);
4. 設(shè)計(jì)Servlet類(lèi)servlet.DeleteBatchServlet

@WebServlet(name = "DeleteBatchServlet",value = "/deleteBatch.action")
public class DeleteBatchServlet extends HttpServlet {
    private static final long serialVersionUID = -6881762699937663920L;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //設(shè)置編碼
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");
        String[] ids = request.getParameterValues("choose");
        MessageMaintainService.deleteBatch(ids);
        System.out.println("批量刪除成功");
        response.sendRedirect("/list.action");
        //這里使用的是請(qǐng)求重定向到list頁(yè). 不會(huì)傳遞req,resp對(duì)象.查詢刪除后會(huì)跳轉(zhuǎn)到全部數(shù)據(jù)頁(yè)面.
//        request.getRequestDispatcher("/list.action").forward(request, response);
    }
}

5. list.jsp頁(yè)面checkbox傳值及全選全不選

<input type="checkbox" name="choose" value="<%=message1.getId()%>"  />
<!--刪除按鈕-->
<a class="btn03" href="javascript:(function() {var form=document.getElementById('mainForm');
form.action='deleteBatch.action';form.submit();})()">刪 除</a>
<!--全選checkbox-->
<input type="checkbox" id="all" onclick="(function() {
    var chooses=document.getElementsByName('choose');                                  
    if(document.getElementById('all').checked) for(var i=0;i<chooses.length;i++) chooses[i].checked=true;
    else for(var j=0;j<chooses.length;j++) chooses[j].checked=false;})()" />

4.5 實(shí)現(xiàn)自動(dòng)回復(fù)功能

模仿微信對(duì)話頁(yè)面html
WEB-INF/jsp/front/talk.jsp

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ page language="java" contentType="text/html;charset=UTF-8" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>微信公眾號(hào)</title>
    <!--討論區(qū)滾動(dòng)條begin-->
    <link rel="stylesheet" type="text/css" href="<%= basePath %>resources/css/jscrollpane1.css" />
    <script src="<%= basePath %>resources/js/common/jquery-1.8.0.min.js" type="text/javascript"></script>
    <!-- the mousewheel plugin -->
    <script type="text/javascript" src="<%= basePath %>resources/js/common/jquery.mousewheel.js"></script>
    <!-- the jScrollPane script -->
    <script type="text/javascript" src="<%= basePath %>resources/js/common/jquery.jscrollpane.min.js"></script>
    <script type="text/javascript" src="<%= basePath %>resources/js/common/scroll-startstop.events.jquery.js"></script>
    <!--討論區(qū)滾動(dòng)條end-->
    <script type="text/javascript" src="<%= basePath %>resources/js/front/talk.js"></script>
    </head>
    <body>
        <input type="hidden" value="<%= basePath %>" id="basePath"/>
        <br/>
        <div class="talk">
            <div class="talk_title"><span>正在與公眾號(hào)對(duì)話</span></div>
            <div class="talk_record">
                <div id="jp-container" class="jp-container">
                    
                </div>
            </div>
            
            <div class="talk_word">
                 
                <input class="add_face" id="facial" type="button" title="添加表情" value="" />
                <input id="content" class="messages emotion"   />
                <input class="talk_send" onclick="send();" type="button" title="發(fā)送" value="發(fā)送" />
            </div>
        </div>
        <div style="text-align:center;margin:50px 0; font:normal 14px/24px 'MicroSoft YaHei';"></div>
    </body>
</html>

talk.jsp對(duì)應(yīng)的數(shù)據(jù)處理js方法
resources/js/front/talk.js

/**
 * 頁(yè)面加載
 */
$(function(){
    render();
    var content = "客官怀跛，來(lái)啦畴博，坐吧！<br/>回復(fù)[查看]收取更多精彩內(nèi)容娇钱。";
    content += "<br/>回復(fù)[幫助]可以查看所有可用的指令。";
    // 添加公眾號(hào)的開(kāi)場(chǎng)白
    appendDialog("talk_recordbox","公眾號(hào)",content);
    render();
});

/**
 * 發(fā)送消息
 * @param basePath
 */
function send() {
    var content = $("#content").val();
    /**
     * content = ""/null/undefined/數(shù)字0 , 則判定為false.
     */
    if(!content) {
        alert("請(qǐng)輸入內(nèi)容累榜！");
        return;
    }
    $.ajax({
        //      <input type="hidden" value="<%= basePath %>" id="basePath"/>
        //通過(guò)這個(gè)標(biāo)簽取值, 減少參數(shù)的傳遞.跳轉(zhuǎn)到指定Servlet
        url : $("#basePath").val() + "AutoReplyServlet.action",
        type : "POST",
        dataType : "text",
        timeout : 10000,
        success : function (data) {
            appendDialog("talk_recordboxme","My賬號(hào)",content);
            appendDialog("talk_recordbox","公眾號(hào)",data);
            //清空文本框內(nèi)容
            $("#content").val("");
            render();
        },
        data : {"content":content}
    });
}

/**
 * 渲染方法谴垫，加載滾動(dòng)條
 */
function render() {
    // the element we want to apply the jScrollPane
    var $el= $('#jp-container').jScrollPane({
        verticalGutter  : -16
    }),
    // the extension functions and options  
    extensionPlugin     = {
        extPluginOpts   : {
            // speed for the fadeOut animation
            mouseLeaveFadeSpeed : 500,
            // scrollbar fades out after hovertimeout_t milliseconds
            hovertimeout_t      : 1000,
            // if set to false, the scrollbar will be shown on mouseenter and hidden on mouseleave
            // if set to true, the same will happen, but the scrollbar will be also hidden on mouseenter after "hovertimeout_t" ms
            // also, it will be shown when we start to scroll and hidden when stopping
            useTimeout          : true,
            // the extension only applies for devices with width > deviceWidth
            deviceWidth         : 980
        },
        hovertimeout    : null, // timeout to hide the scrollbar
        isScrollbarHover: false,// true if the mouse is over the scrollbar
        elementtimeout  : null, // avoids showing the scrollbar when moving from inside the element to outside, passing over the scrollbar
        isScrolling     : false,// true if scrolling
        addHoverFunc    : function() {
            // run only if the window has a width bigger than deviceWidth
            if( $(window).width() <= this.extPluginOpts.deviceWidth ) return false;
            var instance        = this;
            // functions to show / hide the scrollbar
            $.fn.jspmouseenter  = $.fn.show;
            $.fn.jspmouseleave  = $.fn.fadeOut;
            // hide the jScrollPane vertical bar
            var $vBar           = this.getContentPane().siblings('.jspVerticalBar').hide();
            /*
             * mouseenter / mouseleave events on the main element
             * also scrollstart / scrollstop - @James Padolsey : http://james.padolsey.com/javascript/special-scroll-events-for-jquery/
             */
            $el.bind('mouseenter.jsp',function() {
                
                // show the scrollbar
                $vBar.stop( true, true ).jspmouseenter();
                
                if( !instance.extPluginOpts.useTimeout ) return false;
                
                // hide the scrollbar after hovertimeout_t ms
                clearTimeout( instance.hovertimeout );
                instance.hovertimeout   = setTimeout(function() {
                    // if scrolling at the moment don't hide it
                    if( !instance.isScrolling )
                        $vBar.stop( true, true ).jspmouseleave( instance.extPluginOpts.mouseLeaveFadeSpeed || 0 );
                }, instance.extPluginOpts.hovertimeout_t );
            }).bind('mouseleave.jsp',function() {
                // hide the scrollbar
                if( !instance.extPluginOpts.useTimeout )
                    $vBar.stop( true, true ).jspmouseleave( instance.extPluginOpts.mouseLeaveFadeSpeed || 0 );
                else {
                clearTimeout( instance.elementtimeout );
                if( !instance.isScrolling )
                        $vBar.stop( true, true ).jspmouseleave( instance.extPluginOpts.mouseLeaveFadeSpeed || 0 );
                }
            });
            if( this.extPluginOpts.useTimeout ) {
                $el.bind('scrollstart.jsp', function() {
                    // when scrolling show the scrollbar
                    clearTimeout( instance.hovertimeout );
                    instance.isScrolling    = true;
                    $vBar.stop( true, true ).jspmouseenter();
                }).bind('scrollstop.jsp', function() {
                    // when stop scrolling hide the scrollbar (if not hovering it at the moment)
                    clearTimeout( instance.hovertimeout );
                    instance.isScrolling    = false;
                    instance.hovertimeout   = setTimeout(function() {
                        if( !instance.isScrollbarHover )
                                $vBar.stop( true, true ).jspmouseleave( instance.extPluginOpts.mouseLeaveFadeSpeed || 0 );
                        }, instance.extPluginOpts.hovertimeout_t );
                });
                // wrap the scrollbar
                // we need this to be able to add the mouseenter / mouseleave events to the scrollbar
                var $vBarWrapper    = $('<div/>').css({
                    position    : 'absolute',
                    left        : $vBar.css('left'),
                    top         : $vBar.css('top'),
                    right       : $vBar.css('right'),
                    bottom      : $vBar.css('bottom'),
                    width       : $vBar.width(),
                    height      : $vBar.height()
                }).bind('mouseenter.jsp',function() {
                    clearTimeout( instance.hovertimeout );
                    clearTimeout( instance.elementtimeout );
                    instance.isScrollbarHover   = true;
                    // show the scrollbar after 100 ms.
                    // avoids showing the scrollbar when moving from inside the element to outside, passing over the scrollbar                              
                    instance.elementtimeout = setTimeout(function() {
                        $vBar.stop( true, true ).jspmouseenter();
                    }, 100 );   
                }).bind('mouseleave.jsp',function() {
                    // hide the scrollbar after hovertimeout_t
                    clearTimeout( instance.hovertimeout );
                    instance.isScrollbarHover   = false;
                    instance.hovertimeout = setTimeout(function() {
                    // if scrolling at the moment don't hide it
                    if( !instance.isScrolling )
                            $vBar.stop( true, true ).jspmouseleave( instance.extPluginOpts.mouseLeaveFadeSpeed || 0 );
                    }, instance.extPluginOpts.hovertimeout_t );
                });
                $vBar.wrap( $vBarWrapper );
            }
        }
    },
    // the jScrollPane instance
    jspapi = $el.data('jsp');
    // extend the jScollPane by merging 
    $.extend( true, jspapi, extensionPlugin );
    jspapi.addHoverFunc();
}

/**
 * 向聊天記錄中添加聊天內(nèi)容
 * @param myClass 添內(nèi)容的樣式
 * @param name 發(fā)送消息的賬號(hào)名稱(chēng)
 * @param content 發(fā)送的內(nèi)容
 */
function appendDialog(myClass,name,content) {
    var div = "";
    div += "<div class='" + myClass + "'>";
    div += "<div class='user'>![](" + $("#basePath").val() + "resources/images/thumbs/" + myClass + ".jpg)" + name + "</div>";
    div += "<div class='talk_recordtextbg'> </div>";
    div += "<div class='talk_recordtext'>";
    div += "<h3>" + content + "</h3>";
    div += "<span class='talk_time'>" + getCurrentDate() + "</span>";
    div += "</div>";
    div += "</div>";
    $('#jp-container').children().eq(0).children().eq(0).append(div);
}

/**
 * 獲取當(dāng)前系統(tǒng)時(shí)間
 * @returns {String} 當(dāng)前系統(tǒng)時(shí)間
 */
function getCurrentDate() {
    var date = new Date();
    return date.getFullYear() + "-" + (date.getMonth() + 1) + "-" + date.getDate() + " " + (date.getHours() < 10 ? "0" + date.getHours() : date.getHours()) + ":" + (date.getMinutes() < 10 ? "0" + date.getMinutes() : date.getMinutes());
}

Service層queryBycommand(String);方法
com/qezhhnjy/service/MessageQueryService.java

    public static String queryByCommand(String command) {
        List<Message> messageList;
        //設(shè)置輸入'幫助'返回全部數(shù)據(jù)
        //Iconst.HELP_COMMAND為自定義幫助字符串常量
        if (Iconst.HELP_COMMAND.equals(command)){
            messageList = MessageListDao.mybatisQuery(null, null);
            StringBuilder sb = new StringBuilder();
            for (Message message : messageList) {
                sb.append("回復(fù)[").append(message.getCommand()).append("],").append("查看[").append(message.getDescription()).append("]").append("<br/>");
            }
            return sb.toString();
        }
        messageList = MessageListDao.mybatisQuery(command, null);
        if (messageList.size() > 0) return messageList.get(0).getContent();
//Iconst.NO_MATCHING_CONTENT為自定義無(wú)匹配的返回字符串常量.
        return Iconst.NO_MATCHING_CONTENT;
    }

第五章 實(shí)戰(zhàn)第四部

5.1 一對(duì)多關(guān)系的配置 Ⅰ

如果回復(fù)"段子", 而機(jī)器人返回的始終是一個(gè)笑話,就很無(wú)聊了.
所以需要實(shí)現(xiàn)一個(gè)指令能夠隨機(jī)回復(fù)多條內(nèi)容中的一條的功能.

重新設(shè)計(jì)數(shù)據(jù)表

command 表 : ID /commandname/description
content表: ID/content/command_ID(froeign key)

5.2 一對(duì)多關(guān)系的配置 Ⅱ

Content.xml

<mapper namespace="Content">
    <resultMap type="com.qezhhnjy.bean.Content" id="ContentResult">
        <id column="id" jdbcType="VARCHAR" property="id"/>
        <result column="cid" jdbcType="VARCHAR" property="cid"/>
        <result column="content" jdbcType="VARCHAR" property="content"/>
    </resultMap>
</mapper>

Command.xml

<mapper namespace="Command">
    <resultMap type="com.qezhhnjy.bean.Command" id="CommandResult">
        <id column="c_id" jdbcType="VARCHAR" property="id"/>
         <!--這里的列名對(duì)應(yīng)下面select標(biāo)簽中的結(jié)果. 不包括前面的a./b.==,可以使用別名.-->
        <result column="command" jdbcType="VARCHAR" property="command"/>
        <result column="description" jdbcType="VARCHAR" property="description"/>
        <collection property="contents" resultMap="Content.ContentResult" />
        <!--contents為Command實(shí)體類(lèi)中的content集合的屬性名-->
    </resultMap>

    <select id="query" parameterType="com.qezhhnjy.bean.Command" resultMap="CommandResult" >
        SELECT a.id c_id,a.command,a.description,b.id,b.content
        FROM command a LEFT JOIN content b ON a.id=b.cid WHERE 1=1
        <if test="command != null && !"".equals(command.trim())">
            AND command = #{command}
        </if>
        <if test="description != null and !"".equals(description.trim())">
            AND description LIKE '%' #{description} '%'
        </if>
    </select>
</mapper>

最后在Configuration.xml中添加這兩個(gè)實(shí)體類(lèi)的xml文件映射.

5.3 一對(duì)多關(guān)系的配置 Ⅲ

5.4 常用標(biāo)簽

<where></where>標(biāo)簽
Message.xml

      SELECT id,command,description,content FROM MESSAGE WHERE 1=1
      <if test="command != null && !"".equals(command.trim())">
           AND command = #{command}
      </if>
      <if test="description != null and !"".equals(description.trim())">
           AND description LIKE '%' #{description} '%'
      </if>

等效于

      SELECT id,command,description,content FROM message
      <where>
          <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>

where標(biāo)簽可以在沒(méi)有可選項(xiàng)時(shí)去除WHERE關(guān)鍵字. 在有可選項(xiàng)時(shí)去除第一個(gè)條件前面的and或者or.

<sql></sql>標(biāo)簽(與select標(biāo)簽同一級(jí))

     SELECT <include refid="columns" /> FROM message
     <where>
         <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>
   <sql id="columns">id,command,description,content</sql>

<set></set>標(biāo)簽

<update id="">
UPDATE message
      <set>
          <if  test="command != null and !"".equals(command.trim())">command=#{command},
          </if>
          <if  test="description != null and !"".equals(description.trim())">description=#{description},
          </if>
      </set>
</update>

<set>標(biāo)簽可以不必考慮<if>中內(nèi)容的','的取舍問(wèn)題.

<trim></trim>標(biāo)簽與where/set同級(jí)

      <trim prefix="" suffix="" prefixOverrides="and/or" suffixOverrides=""></trim>

表示如果標(biāo)簽里有內(nèi)容輸出, 則 分別加上prefix/suffix指定的前綴和后綴.
prefixOverrides表示輸出內(nèi)容最前面有指定內(nèi)容則切除. 上面就表示有and或者or時(shí)切掉and或者or.
suffixOverrides同理.

<choose></choose>標(biāo)簽

<choose>
    <when test=""></when>
    <when test=""></when>
    <when test=""></when>
    <otherwise></otherwise>
</choose>

類(lèi)似java中的if...else及switch語(yǔ)句.

<association></association>標(biāo)簽(與collection相反)
用于在子表中映射父表

第六章 戰(zhàn)斗總結(jié)

6.1 容易混淆的概念

resultType指直接設(shè)定結(jié)果集映射為某個(gè)工具類(lèi)或?qū)嶓w類(lèi).
為實(shí)體類(lèi)時(shí)列名與類(lèi)中屬性名需一一對(duì)應(yīng),忽略大小寫(xiě).
為工具類(lèi), 如java.util.Map時(shí).以列名為Key, 取值為value. 大小寫(xiě)敏感.

parameterMap用法與resultMap類(lèi)似. 不推薦使用deprecated.

#{}有預(yù)編譯效果,在console中會(huì)以?顯示,
${}沒(méi)有預(yù)編譯效果, 在console中會(huì)以其值顯示
${段子} 顯示為: WHERE command=段子 .這個(gè)sql語(yǔ)句片段是錯(cuò)誤的.段子前后沒(méi)有單引號(hào).正確的用法應(yīng)該是'${段子}'.
${}的用法主要在于order by ×××?xí)r. 如果用預(yù)編譯則會(huì)以?替代.沒(méi)有效果 .在表頭onclick事件按照該列進(jìn)行排列時(shí), 通過(guò)傳遞該列列名然后利用${×××}編譯到sql語(yǔ)句中進(jìn)行動(dòng)態(tài)排序.

如果parameterType為String及8中基本數(shù)據(jù)類(lèi)型. #{}可以寫(xiě)成#{_parameter}.也可以#{}或者中間可以隨便寫(xiě)別的. 都不會(huì)影響.此時(shí),這個(gè)值是確定的. 而ognl表達(dá)式則依然只能寫(xiě)_parameter.
但依然不推薦省略或者亂寫(xiě).

6.2 常見(jiàn)問(wèn)題解析

1. 獲取自增主鍵值
在對(duì)command進(jìn)行插入時(shí), 由于command.id為mysql自增. 不需要進(jìn)行設(shè)置. 那么在插入command后, 應(yīng)該怎樣獲取到這個(gè)自增的id,作為content的外鍵添加command包含的contents.

<!--插入一對(duì)多單方時(shí)設(shè)置實(shí)體類(lèi)獲取數(shù)據(jù)庫(kù)中單方自增生成的主鍵來(lái)設(shè)置多方的外鍵
    useGeneratedKeys為true表示主鍵為mysql自增.keyProperty表示mybatis獲取的主鍵值添加到實(shí)體類(lèi)的該屬性-->
<insert id="insert" parameterType="com.qezhhnjy.bean.Command"
            useGeneratedKeys="true" keyProperty="id" >
    INSERT INTO command(command,description) VALUES(#{command},#{description})
</insert>

2. 找不到namespace.id的異常效果
需要在Configuration.xml中映射各個(gè)實(shí)體類(lèi)的xml文件. 否則運(yùn)行就會(huì)出現(xiàn)這個(gè)異常.

3. sql語(yǔ)句編寫(xiě)錯(cuò)誤

4. 不要過(guò)度使用${}

5. 亂碼