JDOM使用實例--外星人是否存在的調查



/*********************************************
*Author:Java619
*Time:2007-02-14
**********************************************/

這邊以一個實例介紹下,JDOM(這邊使用Jdom-b9)的用法,以及中文問題的解決方法. 

實例使用JSP作爲視圖,結合使用AJAX(用到prototype-1.4),Servlet和JavaBean作爲後臺處理

1.應用目錄結構如下:

data
  |--comment.xml
js
  |--prototype.js
  |--ufo.js
css
  |--ufo.css
images
  |--loading.gif
ufo.jsp
WEB-INF
  |-lib
     |-jaxen-core.jar
     |-jaxen-jdom.jar
     |-jdom.jar
     |-sax.jar
     |-saxpath.jar
  |-classes
     ...
  |-web.xml

2.後臺JavaBean  CommentBean.java

/** *//**
 * <P>外星人是否存在評論系統</p>
 * @author ceun
 * 聯繫作者:<br>
 *    <a href="mailto:[email protected]">ceun</a><br>
 * @version 1.0 2007-01-30 實現基本功能<br>
 * CommentBean.java
 * Created on Jan 30, 2007 9:39:19 AM
 */
package com.ceun.bean;

import java.io.FileWriter;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Random;

import org.jdom.CDATA;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.Text;
import org.jdom.input.SAXBuilder;
import org.jdom.output.XMLOutputter;

/** *//**
 *<p> 封裝對XML的操作</p>
 * @author ceun
 * 聯繫作者:<br>
 *    <a href="mailto:[email protected]">ceun</a><br>
 * @version 1.0 2007-01-30 實現基本功能<br>
 */
public class CommentBean ...{
    private String filepath;

    private SAXBuilder builder = null;

    private Document doc = null;

    public CommentBean() ...{

    }
/** *//**
 * 初始化XML文件路徑,加載文件
 * */
    public CommentBean(String path) ...{
        this.filepath = path;
        builder = new SAXBuilder();
        try ...{
            doc = builder.build(filepath);
        } catch (JDOMException e) ...{
            System.out.print("找不到指定的XML文件");
            e.printStackTrace();
        } catch (IOException e) ...{
            System.out.print("找不到指定的文件");
            e.printStackTrace();
        }
    }
 /** *//**
  * 添加評論
  * @param nikename 評論者暱稱
  * @param comment 評論內容
  * @param attitude 評論者的結論(yes-存在,no-不存在)
  * */
    public String addComment(String nikename, String comment, String attitude) ...{
        Element root = doc.getRootElement();

        Element el = new Element("comment");
        Random rand = new Random();
        int id = rand.nextInt(10000);
        el.setAttribute("id", "comment_" + id);
        el.setAttribute("attitude", attitude);

        Element name = new Element("nikename");
        CDATA cname = new CDATA(nikename);
        name.addContent(cname);

        Element data = new Element("data");
        CDATA ctext = new CDATA(comment);
        data.addContent(ctext);

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = new Date();
        Text tdate = new Text(format.format(date));
        Element pubdate = new Element("pubdate");
        pubdate.addContent(tdate);

        el.addContent(name);
        el.addContent(data);
        el.addContent(pubdate);
        root.addContent(el);
        XMLOutputter outputter = new XMLOutputter("  ", true, "GB2312");
        // 清除comment元素間的空格
        outputter.setTrimAllWhite(true);
        try ...{
            outputter.output(doc, new FileWriter(filepath));
        } catch (IOException e) ...{
            System.out.println("指定路徑有錯");
            e.printStackTrace();
        }
        return tdate.getText();
    }
/** *//**
 * 刪除指定ID的評論
 * @param commentId 評論ID
 * @return 返回操作結果字符串(成功或失敗)
 * */
    public String removeComment(String commentId) ...{
        Element root = doc.getRootElement();
        List comments = root.getChildren();
        int size = comments.size();
        Element dist = null;
        for (int i = 0; i < size; i++) ...{
            Element comment = (Element) comments.get(i);
            String id = comment.getAttributeValue("id");
            if (id.equals(commentId)) ...{
                dist = comment;
                break;
            }
        }
        if (dist != null) ...{
            root.removeContent(dist);
            XMLOutputter outputter = new XMLOutputter("  ", true, "GB2312");
            // 清除comment元素間的空格
            outputter.setTrimAllWhite(true);
            try ...{
                outputter.output(doc, new FileWriter(filepath));
            } catch (IOException e) ...{
                System.out.println("重寫文件有出錯");
                e.printStackTrace();
            }
            return "成功刪除指定元素!";
        } else
            return "指定元素不存在!";
    }
/** *//**
 * 批量刪除評論
 * @param commentIdArgs 評論ID數組
 * @return 返回操作結果字符串(成功或失敗)
 * */
    public String removeComments(String[] commentIdArgs) ...{
        Element root = doc.getRootElement();
        List comments = root.getChildren();
        int size = comments.size();
        int len = commentIdArgs.length;
        List<Element> dist = new ArrayList<Element>();
        outer:for (int i = 0; i < size; i++) ...{
            Element comment = (Element) comments.get(i);
            String id = comment.getAttributeValue("id");

            for (int j = 0; j < len; j++)
                if (id.equals(commentIdArgs[j])) ...{
                    dist.add(comment);
                    continue outer;
                }
        }
        int dist_size=dist.size();
        if (dist_size != 0) ...{
            for (int i = 0; i < dist_size; i++)
                root.removeContent(dist.get(i));
            XMLOutputter outputter = new XMLOutputter("  ", true, "GB2312");
            // 清除comment元素間的空格
            outputter.setTrimAllWhite(true);
            try ...{
                outputter.output(doc, new FileWriter(filepath));
            } catch (IOException e) ...{
                System.out.println("重寫文件有出錯");
                e.printStackTrace();
            }
            return "成功刪除指定的元素集合!";
        } else
            return "指定元素集合的不存在!";
    }

    /** *//**
     * @return the filepath
     */
    public String getFilepath() ...{
        return filepath;
    }

    /** *//**
     * @param filepath
     *            the filepath to set
     */
    public void setFilepath(String filepath) ...{
        this.filepath = filepath;
    }

    /** *//**
     * @return the builder
     */
    public SAXBuilder getBuilder() ...{
        return builder;
    }

    /** *//**
     * @param builder
     *            the builder to set
     */
    public void setBuilder(SAXBuilder builder) ...{
        this.builder = builder;
    }
}

3.處理AJAX請求的Servlet  AddCommentServlet.java

package com.ceun.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.ceun.bean.CommentBean;
/** *//**
 * <p>後臺處理Servlet</p>
 *2007-01-30
 * * @author ceun
 * 聯繫作者:<br>
 *    <a href="mailto:[email protected]">ceun</a><br>
 * @version 1.0 2007-01-30 實現基本功能<br>
 * */
public class AddCommentServlet extends HttpServlet ...{

    /** *//**
     * serialVersionUID long
     */
    private static final long serialVersionUID = 1L;

    /** *//**
     * The doGet method of the servlet. <br>
     * 
     * This method is called when a form has its tag value method equals to get.
     * 
     * @param request
     *            the request send by the client to the server
     * @param response
     *            the response send by the server to the client
     * @throws ServletException
     *             if an error occurred
     * @throws IOException
     *             if an error occurred
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        response.setHeader("Cache-Control", "no-cache");
    
        PrintWriter out = response.getWriter();
        String nikename = request.getParameter("nn");
    
        String comment = request.getParameter("rsn");
        String attitude = request.getParameter("atti");
        String filepath = request.getSession().getServletContext().getRealPath(
                "data/comment.xml");
        CommentBean bean = new CommentBean(filepath);
        String str = bean.addComment(nikename, comment, attitude);
        out.println(str);
    }

    /** *//**
     * The doPost method of the servlet. <br>
     * 
     * This method is called when a form has its tag value method equals to
     * post.
     * 
     * @param request
     *            the request send by the client to the server
     * @param response
     *            the response send by the server to the client
     * @throws ServletException
     *             if an error occurred
     * @throws IOException
     *             if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{

        doGet(request, response);
    }

}

4.JSP視圖 ufo.jsp

<%...@ page contentType="text/html;charset=UTF-8"%>
<%...
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh_CN" lang="zh_CN">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
        <meta http-equiv="pragma" content="no-cache" />
        <meta http-equiv="cache-control" content="no-cache" />
        <meta http-equiv="expires" content="0" />
        <title>ufo</title>
        <link rel="stylesheet" type="text/css" href="css/ufo.css"/>
        <script src="<%=basePath%>js/prototype.js" type="text/javascript"></script>
        <script src="<%=basePath%>js/ufo.js" type="text/javascript"></script>
    </head>
    <SCRIPT type="text/javascript">...
<!--
window.onload=function()...{
getComments("<%=basePath%>data/comment.xml");
}
//-->
</SCRIPT>
    <body>
        <div id="cinfoDiv" style="display:none;">
            <h2>
                信息提示
            </h2>
            <p id="cinfomsg">
            </p>
        </div>
        <table id="process-indicator"
            style="display:none;z-index:100;width:300px;">
            <tr>
                <td>
                    <img src="images/loading.gif" />
                    <p>
                        正在處理中...
                    </p>
                </td>
            </tr>
        </table>
        <center>
            <div id="comment-lists">

            </div>

            <div id="comment">
                <div style="display:none;top:100px;left:200px;" id="locateDiv1">

                </div>
                <div id="comment-bar">
                    你認爲外星人存在嗎?
                </div>
                <div id="comment-form">
                    <form onsubmit="return false;" name="cform">
                        暱稱:
                        <input type="text" id="nn" name="nn" />
                        <input type="radio" id="exist" name="exist" value="yes" />
                        存在
                        <input type="radio" id="exist" name="exist" value="no" />
                        不存在
                        <br />
                        <textarea name="reason" style="width: 480px;height:200px;"
                            id="reason"></textarea>
                        <button id="btnsubmit" class="button"
                            onclick="addComment('<%=path%>/addCommentServlet');">
                            發表你的看法
                        </button>
                        <input type="reset" id="btnreset" class="button" />
                    </form>
                </div>
            </div>
        </center>
    </body>
</html>

5.前臺腳本 ufo.js

var Browser = ...{};
Browser.isMozilla = (typeof document.implementation != "undefined") && (typeof document.implementation.createDocument != "undefined") && (typeof HTMLDocument != "undefined");
Browser.isIE = window.ActiveXObject ? true : false;
Browser.isFirefox = (navigator.userAgent.toLowerCase().indexOf("firefox") != -1);
Browser.isSafari = (navigator.userAgent.toLowerCase().indexOf("safari") != -1);
Browser.isOpera = (navigator.userAgent.toLowerCase().indexOf("opera") != -1);
String.prototype.trim=function()...{return this.replace(/^s+|s+$/g,"");};
function addComment(url)...{
var nn=$F("nn");
var rsn=$F("reason");
var atti=false;
var rbgroup=document.cform.elements["exist"];
for(i=0;i<rbgroup.length;i++)...{
  if(rbgroup[i].checked) ...{atti=rbgroup[i].value;break;};
}
var locateTop=$("locateDiv1").parentNode.offsetTop-50;
var locateLeft=$("locateDiv1").parentNode.offsetLeft+150;
var alertMsg="";
if(!atti)
  alertMsg+="<br/>請表明你的態度!";
if(nn.trim()=="")
  alertMsg+="<br/>暱稱不能爲空!"
if(rsn.trim()=="")
  alertMsg+="<br/>請寫下你的理由!";

var cinfomsg=$("cinfomsg");
if(alertMsg!="")...{
  cinfomsg.className="failure";
  cinfomsg.innerHTML=alertMsg;
  showDialog($("cinfoDiv"),locateTop,locateLeft);
  return;
}else...{
  cinfomsg.className="success";
  cinfomsg.innerHTML="正處理數據中...";
  showDialog($("cinfoDiv"),locateTop,locateLeft);
}

var pars="nn="+nn+"&atti="+atti+"&rsn="+rsn;
var http=Ajax.getTransport();
var contentType = "application/x-www-form-urlencoded; charset=utf-8";
http.open("POST",url,true);
http.setRequestHeader("Content-Type", contentType);
http.onreadystatechange=function()...{
     if (http.readyState == 4)...{
      if (http.status==200)...{
         afterAdd(http);
       }
     }
  }
http.send(pars);
}
function afterAdd(request)...{
hideDialog();
var atti=false;
var rbgroup=document.cform.elements["exist"];
for(i=0;i<rbgroup.length;i++)...{
  if(rbgroup[i].checked) ...{atti=rbgroup[i].value;break;};
}
var nn=$F("nn");
var rsn=$F("reason");
generateCommentList(atti,nn,request.responseText,rsn)
$("nn").value="";
$("reason").value="";
}
function generateCommentList(atti,nn,date,rsn)...{
var commentLists=$("comment-lists");

var commentlist=document.createElement("div");
commentlist.className="comment-list";

var observerInfo=document.createElement("div");
observerInfo.className="observer-info";

var attitude=(atti=="yes")?"認爲存在":"認爲不存在";
var info=document.createTextNode("評論者:"+nn+" 觀點:"+attitude+" "+date);
observerInfo.appendChild(info);

var observerComment=document.createElement("div");
observerComment.className="observer-comment";

var reason=document.createTextNode(rsn);
observerComment.appendChild(reason);

commentlist.appendChild(observerInfo);
commentlist.appendChild(observerComment);
if(commentLists.hasChildNodes())...{
  var tmp=commentLists.firstChild;
  commentLists.insertBefore(commentlist,tmp);
}else
  commentLists.appendChild(commentlist);
}
function getComments(url)...{

Element.show("process-indicator");
Element.makePositioned("process-indicator");
var top = document.body.scrollTop + 200;
var left = "";
if ($("process-indicator").style.width) ...{
    left =window.document.body.scrollWidth/2-100;
} else ...{
left = parseInt(document.body.clientWidth / 2);
}
var style = ...{top:top + "px", left:left + "px"};
Element.setStyle("process-indicator", style);
//加個隨機數,去除緩存影響
var pars="rd=rd_"+parseInt(Math.random()*10000);

var http=Ajax.getTransport();
var contentType = "application/x-www-form-urlencoded; charset=utf-8";
http.open("POST",url,true);
http.setRequestHeader("Content-Type", contentType);
http.onreadystatechange=function()...{
     if (http.readyState == 4)...{
      if (http.status==200)...{
         afterGetComments(http);
       }
     }
  }
http.send(pars);
}
function afterGetComments(request)...{
//提示框
Element.hide("process-indicator");
var xmldata=request.responseXML;
var comments=xmldata.getElementsByTagName("comment");
if(!comments)...{alert("暫無評論");return;}
var len=comments.length;
for(var i=0;i<len;i++)...{
  var atti=comments[i].getAttribute("attitude");
  var nn=comments[i].getElementsByTagName("nikename")[0].firstChild.nodeValue;
  var rsn=comments[i].getElementsByTagName("data")[0].firstChild.nodeValue;
  var date=comments[i].getElementsByTagName("pubdate")[0].firstChild.nodeValue;
  generateCommentList(atti,nn,date,rsn)
}
}
 //對話框模塊
var lastDialog=null;
function showDialog(dialog,offsetTop,offsetLeft)...{
    if (lastDialog) lastDialog.style.display="none";
    dialog.style.top=offsetTop+"px";
    dialog.style.left=offsetLeft+"px";
    dialog.style.display="";
    lastDialog=dialog;
    document.onmousedown=toHideDialog
}

function toHideDialog(event)...{
    if (!lastDialog) ...{document.onclick=null;return;}
    var obj=null;
    if(Browser.isIE) obj=window.event.srcElement;
    else obj=event.target;
    hideDialog();
}
    
function hideDialog()...{
    if (lastDialog) lastDialog.style.display="none";
    lastDialog=null
    document.onmousedown=null;
}

6.CSS ufo.css

#comment{...}{
    background-color: InactiveCaptionText;
    width: 550px;
    height:300px;
    margin-top:10px;
    }
    #comment-bar{...}{
        color:white;
        padding-top: 5px;
        padding-bottom: 5px;
        text-align: center;
        background-color: ActiveCaption;
    }
    #comment-form{...}{
        padding-left:20px;
    }
    .button{...}{
        BORDER-RIGHT: #283043 1px solid; PADDING-RIGHT: 1px; BORDER-TOP: #9097a2 1px solid;
    PADDING-LEFT: 1px; BACKGROUND: ActiveCaption;; PADDING-BOTTOM: 1px; 
    BORDER-LEFT: #9097a2 1px solid; COLOR: #fff; 
    PADDING-TOP: 1px; BORDER-BOTTOM: #283043 1px solid;
    margin: 10px;
    }
    #comment-lists{...}{
    background-color: InactiveCaptionText;
    width: 550px;
    margin-bottom:10px;
    }
    div.comment-list{...}{
        text-align: left;
        border:1px solid ActiveCaption;
        margin: 5px;
    }
    div.observer-info{...}{
        color:white;
        padding-top: 5px;
        padding-bottom: 5px;
        padding-left: 5px;
        text-align: left;
        background-color: ActiveCaption;
        font-size: 14px;
    }
    div.observer-comment{...}{
        padding-top: 5px;
        padding-bottom: 5px;
        text-align: left;
    }
    #process-indicator{...}{
     margin:10px;padding-top:15px;padding-right:5px;padding-left:5px;
     background-color:cyan;position:absolute;border:2px solid ActiveCaption;
    }
    .success {...}{
    COLOR: Blue;
}
.failure {...}{
    COLOR: #ff665b
}
#cinfoDiv {...}{
    position:absolute;
    top:10px;
    width:200px;
    height:120px;
    z-index:1000;
    background-color:#F0F8FF;
    border:1px solid #009999
}
#cinfoDiv h2{...}{
background-color:#483D8B;
font-size:14px;
color:#fff;
text-align:center;
margin-top:0px;
}
#cinfoDiv p{...}{
margin:5px;
text-align:center;
vertical-align: top;
font-size:14px;
}

7.comment.xml

 

<?xml version="1.0" encoding="GB2312"?>
<comments>
  <comment id="comment_4119" attitude="yes">
    <nikename><![CDATA[薜荔女蘿衣]]></nikename>
    <data><![CDATA[這個問題要全面分析。 
外星很簡單，相對於地球之外而言。 
人嗎，就給這個生物一個限定性標準了，至少要像人啊。 
存在本身就是一個問題。誰能證明存在是存在的呢？ 
誰又能全面地證明存在是不存在的呢？類似高爾吉亞的智者派的方法就不要再用了。 
之後纔要探討是與否的問題。 
]]></data>
    <pubdate>2007-01-31 20:53:33</pubdate>
  </comment>
  <comment id="comment_5953" attitude="yes">
    <nikename><![CDATA[ぁあ宇宙過客]]></nikename>
    <data><![CDATA[肯定會存在，難道真麼大一個宇宙就只有地球有生物？ 
]]></data>
    <pubdate>2007-01-31 20:56:17</pubdate>
  </comment>
  <comment id="comment_2199" attitude="yes">
    <nikename><![CDATA[匿名]]></nikename>
    <data><![CDATA[存在。如果沒有的話怎麼會在恐龍的肚子中找到一個相似外星化石呢？]]></data>
    <pubdate>2007-01-31 21:00:43</pubdate>
  </comment>
  <comment id="comment_8637" attitude="yes">
    <nikename><![CDATA[互相幫助小組]]></nikename>
    <data><![CDATA[有高等智慧生物吧，但不一定是人的形勢啊！我堅信它們的存在。]]></data>
    <pubdate>2007-01-31 21:03:21</pubdate>
  </comment>
  <comment id="comment_237" attitude="yes">
    <nikename><![CDATA[秦國園林]]></nikename>
    <data><![CDATA[我就是外星人,我乘坐的大型飛行器----地球,不知什麼時侯回到我的家鄉----宇宙的起點.自從人類產生就和那失去了聯繫,你能告訴我航行的方向嗎?船長先生. 
]]></data>
    <pubdate>2007-01-31 21:11:06</pubdate>
  </comment>
</comments>