一般來(lái)說(shuō),Ajax程序中,ResponseXml輸出一般使用XML拼接,舉例如下:
PrintWriter out = response.getWriter();
out.println("<response>");
List<InOutType> types = service.search(predicate);
out.println("<status>passed</status>");
out.println("<message>查詢出的記錄數(shù)為:" + types.size() + "條</message>");
for (InOutType typeTmp : types) 
{
out.println("<type>");
out.println("<name>" + typeTmp.getName() + "</name>");
out.println("</type>");
}
out.println("</response>");
個(gè)人認(rèn)為這樣的方式用在小規(guī)模(編輯器一屏之內(nèi))ResponseXml還行,大規(guī)模就容易出錯(cuò)了,它有以下缺點(diǎn):
1.節(jié)點(diǎn)開(kāi)始如<response>和節(jié)點(diǎn)結(jié)束</response>必須成對(duì)書寫,容易遺忘出錯(cuò).
2.節(jié)點(diǎn)和子節(jié)點(diǎn)關(guān)系不清晰.
我設(shè)想用dom4j來(lái)解決這個(gè)問(wèn)題,具體就是把上述代碼中的XML轉(zhuǎn)化成一個(gè)Document的節(jié)點(diǎn),這樣成對(duì)書寫問(wèn)題和節(jié)點(diǎn)關(guān)系的問(wèn)題都能解決了.
具體的類如下:
package com.sitinspring.nnyy.util;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
public class XmlAssemble{
private Document document;
private Element root;
public XmlAssemble(String rootName){
document=DocumentHelper.createDocument();
root = document.addElement(rootName);
}
public String getXml(){
return document.asXML();
}
public Element add(String elmName){
return root.addElement(elmName);
}
public Element add(String elmName,String elmTxt){
Element elm=root.addElement(elmName);
elm.setText(elmTxt);
return elm;
}
public Element getRoot() {
return root;
}
}
在這個(gè)類的幫助下,原有代碼改寫為:
List<InOutType> types = service.search(predicate);
XmlAssemble xmlAssemble=new XmlAssemble("response");
xmlAssemble.add("status","passed");
xmlAssemble.add("message","查詢出的記錄數(shù)為:"+ types.size() + "條");
for (InOutType typeTmp : types) {
Element typeElm=xmlAssemble.add("type");
Element nameElm=typeElm.addElement("name");
nameElm.setText(typeTmp.getName());
}
PrintWriter out = response.getWriter();
out.println(xmlAssemble.getXml());
明顯,上述代碼沒(méi)有書寫問(wèn)題和節(jié)點(diǎn)關(guān)系問(wèn)題,它的書寫過(guò)程是逐漸深入子節(jié)點(diǎn)的,代碼連貫性好多了,即使代碼超過(guò)一屏也能有效控制.
以上.