飛舞的幻想

一個WebWork實現的簡單登錄過程以及遇到問題并附代碼

1.login.jsp中點擊submit按紐后,請求將被發送到web容器的login.action,
2.web容器檢索web.xml,通過
<servlet-mapping>
??????? <servlet-name>webwork</servlet-name>
??????? <url-pattern>*.action</url-pattern>
??? </servlet-mapping>

這一段得到webwork關鍵字,再通過
??? <servlet>
??????? <servlet-name>webwork</servlet-name>
??????? <servlet-class>
??????????? com.opensymphony.webwork.dispatcher.ServletDispatcher
??????? </servlet-class>

??????? <load-on-startup>1</load-on-startup>
??? </servlet>

將請求轉發給com.opensymphony.webwork.dispatcher.ServletDispatcher類來處理,這個類會讀取xwork.xml文件
3.通過和最初login.jsp提交的"login.action"中去掉web.xml中的定義的".action", 得到"login",在xwork.xml中的
??????? <action name="login" class="com.cdpgc.salary.LoginAction">
??????????? <result name="failed" type="dispatcher">login-failed.jsp</result>
??????????? <result name="success" type="dispatcher">login-success.jsp</result>
??????? </action>

找到"login"的定義,并尋找com.cdpgc.salary.LoginAction來處理這個請求,當該對象的execute()方法返回
<result>節點"name"屬性定義的字符串的時候,將結果使用某個jsp來響應.這里是
success->login-success.jsp
failed->login-failed.jsp
4.兩個jsp中使用了
<ww:property value="user" />

來訪問處理類(com.cdpgc.salary.LoginAction)的屬性,它依賴于
<%@ taglib uri="webwork" prefix="ww" %>

定義的標簽庫,而這個標簽庫定義中的uri依賴于web.xml中的
??? <taglib>
??????? <taglib-uri>webwork</taglib-uri>
??????? <taglib-location>
??????????? /WEB-INF/lib/webwork-2.1.7.jar
??????? </taglib-location>
??? </taglib>

定義的taglib-uri名稱

另外,在LoginAction.java中webwork會將發出請求的form中的值--------在<input type='xxx' name='xxx'>中的值
填入到自己的屬性中(如果有同名屬性的化),這樣我們可以獲得請求參數.在處理完畢后,同樣可以設置它,
而在結果jsp中,webwork又會將該值提供給jsp訪問,當然還是基于名稱相同.

遇到問題
一、webwork jar文件添加,需要的Jar需要添加完備。
二、java.lang.NoSuchMethodError: javax.xml.transform.dom.DOMResult.getNextSibling()Lorg/w3c/dom/Node;
??? org.apache.xalan.transformer.TransformerIdentityImpl.createResultContentHandler(TransformerIdentityImpl.java:199)
??? org.apache.xalan.transformer.TransformerIdentityImpl.setDocumentLocator(TransformerIdentityImpl.java:880)
??? com.opensymphony.xwork.util.DomHelper$DOMBuilder.setDocumentLocator(DomHelper.java:233)
??? com.opensymphony.xwork.util.location.LocationAttributes$Pipe.setDocumentLocator(LocationAttributes.java:302)
??? com.opensymphony.xwork.util.DomHelper$StartHandler.setDocumentLocator(DomHelper.java:292)
??? org.apache.xerces.parsers.AbstractSAXParser.startDocument(Unknown Source)
??? org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(Unknown Source)
??? org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(Unknown Source)
??? org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(Unknown Source)
??? org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
??? org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
??? org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
??? org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
??? javax.xml.parsers.SAXParser.parse(Unknown Source)
??? com.opensymphony.xwork.util.DomHelper.parse(DomHelper.java:122)
??? com.opensymphony.xwork.config.providers.XmlConfigurationProvider.loadConfigurationFile(XmlConfigurationProvider.java:642)
??? com.opensymphony.xwork.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:91)
??? com.opensymphony.xwork.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:85)
??? com.opensymphony.xwork.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:54)
??? com.opensymphony.xwork.DefaultActionProxy.<init>(DefaultActionProxy.java:57)
??? com.opensymphony.xwork.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:46)
??? com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:216)
??? com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:111)
???
問題原因原來是因為使用了tomcat5.0.28它里面的xml-api.jar把jdk1.5里面的DOMResult沖掉了 ，改用Tomcat的5.5版本問題解決。
三、javax.xml.transform.TransformerFactoryConfigurationError: Provider org.apache.xalan.processor.TransformerFactoryImpl not found
javax.xml.transform.TransformerFactory.newInstance(Unknown Source)
com.opensymphony.xwork.util.DomHelper$DOMBuilder.<clinit>(DomHelper.java:168)
com.opensymphony.xwork.util.DomHelper.parse(DomHelper.java:116)
com.opensymphony.xwork.config.providers.XmlConfigurationProvider.loadConfigurationFile(XmlConfigurationProvider.java:642)
com.opensymphony.xwork.config.providers.XmlConfigurationProvider.init(XmlConfigurationProvider.java:91)
com.opensymphony.xwork.config.impl.DefaultConfiguration.reload(DefaultConfiguration.java:85)
com.opensymphony.xwork.config.ConfigurationManager.getConfiguration(ConfigurationManager.java:54)
com.opensymphony.xwork.DefaultActionProxy.<init>(DefaultActionProxy.java:57)
com.opensymphony.xwork.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:46)
com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:216)
com.opensymphony.webwork.dispatcher.ServletDispatcher.service(ServletDispatcher.java:111)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
問題原因缺少xalan.jar文件,去http://xml.apache.org/xalan-j/index.html下載即可。

代碼：login.jsp,loginsucess.jsp,loginfailed.jsp,LoginAction.java.
????? 我們登錄login.jsp,輸入用戶名,post之后,請求將提交給LoginAction處理,如果成功則返回login-success.jsp,否則返回loginfailed.jsp
?
????? login.jsp
<html>
<head>
<title>WebWork Tutorial - Lesson 3 - Example 1</title>
</head>

<body>

<p>
Click the [post] button below to Login.
</p>

<form action="login.action" method="post">
<p>user:<input type="text" name="user" value="" /></p>
<p>password:<input type="password" name="password" value="" /></p>
<p><input type="submit" value="post" /></p>
</form>

</body>
</html>

login-success.jsp

<%@ taglib uri="webwork" prefix="ww" %>
<html>
<head>
<title>welcome to salary</title>
</head>
<body>

<font color="green">

<ww:property value="user" /> has logon [SalaryQueryModule]

</font>
<br>



</body>
</html>

login-failed.jsp

<%@ taglib uri="webwork" prefix="ww" %>
<html>
<head>
<title>failed login</title>
</head>
<body>
<font color="red">
error login by [<ww:property value="user" /> ],invalid user or pwd
</font>
<br>
</body>
</html>

web.xml,位于web-inf目錄下
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
??? xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
??? xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
??? http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

??? <display-name>My WebWork Application</display-name>
??? <servlet>
??????? <servlet-name>webwork</servlet-name>
??????? <servlet-class>
??????????? com.opensymphony.webwork.dispatcher.ServletDispatcher
??????? </servlet-class>

??????? <load-on-startup>1</load-on-startup>
??? </servlet>
??? <servlet-mapping>
??????? <servlet-name>webwork</servlet-name>
??????? <url-pattern>*.action</url-pattern>
??? </servlet-mapping>
???
??? <taglib>
??????? <taglib-uri>webwork</taglib-uri>
??????? <taglib-location>
??????????? /WEB-INF/lib/webwork-2.1.7.jar
??????? </taglib-location>
??? </taglib>
</web-app>

xwork.xml位于web-inf\classes目錄下
<!DOCTYPE xwork PUBLIC "-//OpenSymphony Group//XWork 1.0//EN"
"http://www.opensymphony.com/xwork/xwork-1.0.dtd">

<xwork>
??? <!-- Include webwork defaults (from WebWork JAR). -->
??? <include file="webwork-default.xml" />
???
??? <!-- Configuration for the default package. -->
??? <package name="default" extends="webwork-default">
??????? <!-- Default interceptor stack. -->
??????? <default-interceptor-ref name="defaultStack" />
???????
??????? <!-- Action: Lesson 03: HelloAction. -->
??????? <action name="login" class="com.cdpgc.salary.LoginAction">
??????????? <result name="failed" type="dispatcher">login-failed.jsp</result>
??????????? <result name="success" type="dispatcher">login-success.jsp</result>
??????? </action>
??? </package>
</xwork>

LoginAction.java
?1/**//*
?2 * Created on 2005-8-4
?3 *
?4 * TODO To change the template for this generated file go to
?5 * Window - Preferences - Java - Code Style - Code Templates
?6 */
?7package com.cdpgc.salary;
?8
?9import com.opensymphony.xwork.ActionSupport;
10
11/**//**
12 * @author codemyth
13 *
14 * TODO To change the template for this generated type comment go to Window -
15 * Preferences - Java - Code Style - Code Templates
16 */
17public class LoginAction extends ActionSupport {
18
19??? String user;
20??? String password;
21
22??? /**//*
23???? * (non-Javadoc)
24???? *
25???? * @see com.opensymphony.xwork.Action#execute()
26???? */
27??? public String execute() throws Exception {
28??????? // TODO verify user-password
29??????? if (user.equals("bbb"))
30??????????? return super.SUCCESS;
31??????? else
32??????????? return "failed";
33??? }
34??? /**//**
35???? * @return Returns the user.
36???? */
37??? public String getUser() {
38??????? return user;
39??? }
40??? /**//**
41???? * @param user
42???? *??????????? The user to set.
43???? */
44??? public void setUser(String user) {
45??????? this.user = user;
46??? }
47??? /**//**
48???? * @return Returns the password.
49???? */
50??? public String getPassword() {
51??????? return password;
52??? }
53??? /**//**
54???? * @param password
55???? *??????????? The password to set.
56???? */
57??? public void setPassword(String password) {
58??????? this.password = password;
59??? }
60}
文章大部分內容來自http://www.tkk7.com/codemyth/archive/2005/08/06/9453.html

posted on 2006-12-06 14:39 飛舞的幻想 閱讀(1232) 評論(1)  編輯  收藏 所屬分類: 框架學習