cnhzliye

飞云小侠 2005-7-27 http://www.jscud.com 转载请注明作者


我在项目中经常用到这样的功能:例如添加完一个文章,我通常会提示用户"操作完成",然后转向到文章列表页面或者文章详情页面.以前的做法是使用WebWork本身的dispatcher结果类型,设置结果页面为信息提示页面,在程序中设置目标页面和提示信息.这样虽然也可以完成我的目标,但是目标页面是在程序里面写死的,无法放在配置里.

这几天研究了一下WebWork的Result Type,发现写一个新的Result Type很容易,于是诞生了我的一个新的Result Type:

功能:信息提示并转向到目标页面
流程:在Action中设置提示信息(当然也可以改到配置文件里,但是配置起来略麻烦,所以还是写在程序里了),然后使用我的结果类型msgto,在配置文件里面配置目标页面.


代码如下

1.页面信息提示类(包含页面提示信息和目标页面,停留时间)


package com.jscud.www.support.web;


/*
* Created Date 2004-11-23
*
*/

/**
* 用于页面提示的信息类.
*
* @author scud
*
*/
public class PageMessage
{
/**标题*/
private String msgTitle;

/**内容体*/
private String msgContent;

/**要转向到的网址*/
private String msgToURL;

/**停留时间*/
private int msgToTime = 1 ;


public String getMsgContent()
{
return msgContent;
}

public void setMsgContent(String msgContent)
{
this.msgContent = msgContent;
}

public String getMsgTitle()
{
return msgTitle;
}

public void setMsgTitle(String msgTitle)
{
this.msgTitle = msgTitle;
}

public int getMsgToTime()
{

return msgToTime;
}

public void setMsgToTime(int msgToTime)
{
this.msgToTime = msgToTime;
}

public String getMsgToURL()
{
return msgToURL;
}

public void setMsgToURL(String msgToURL)
{
this.msgToURL = msgToURL;
}
}





2."msgto" Result Type ,借鉴了WebWork本身的几个ResultType,部分代码是copy过来的

package com.jscud.www.support.web;

//import com.jscud.util.LogMan;
import com.opensymphony.webwork.config.Configuration;
import com.opensymphony.webwork.dispatcher.ServletDispatcher;
import com.opensymphony.webwork.dispatcher.WebWorkResultSupport;

import com.opensymphony.webwork.ServletActionContext;
import com.opensymphony.xwork.ActionContext;
import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.util.OgnlValueStack;

import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/*
* Created on 2005-7-26
*
*/

/**
* WebWork Result Type for "msgto".
*
* Message Hint to User then Refresh to another Page.
*
* @author scud.
*
*/
public class ServletMessageToResult extends WebWorkResultSupport
{

//~ Static fields/initializers /////////////////////////////////////////////

private static final String DefaultMessagePage = "/WEB-INF/public/page/msgto.jsp";

protected String messagePage;

protected boolean prependServletContext = true;


//~ Methods ////////////////////////////////////////////////////////////////

public void setMessagePage(String sPagePath)
{
this.messagePage = sPagePath;
}

public String getMessagePage()
{
if (null == messagePage)
{
if (Configuration.isSet("jscud.page.messageto"))
{
this.messagePage = Configuration.getString("jscud.page.messageto");
}
else
{
this.messagePage = DefaultMessagePage;
}
}

return messagePage;
}


/**
* Sets whether or not to prepend the servlet context path to the redirected URL.
*
* @param prependServletContext <tt>true</tt> to prepend the location with the servlet context path,
* <tt>false</tt> otherwise.
*/
public void setPrependServletContext(boolean prependServletContext) {
this.prependServletContext = prependServletContext;
}

/**
* Dispatches to the Message Page. Does its forward via a RequestDispatcher. If the
* dispatch fails a 404 error will be sent back in the http response.
*
* @param finalLocation the location to dispatch to.
* @param invocation the execution state of the action
* @throws Exception if an error occurs. If the dispatch fails the error will go back via the
* HTTP request.
*/
public void doExecute(String finalLocation, ActionInvocation invocation)
throws Exception
{
String messageLocation = getMessagePage();

HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();

RequestDispatcher dispatcher = request.getRequestDispatcher(messageLocation);

// if the view doesn't exist, let's do a 404
if (dispatcher == null)
{
response.sendError(404, "message page '" + messageLocation + "' not found");

return;
}

request.setAttribute("webwork.view_uri", messageLocation);
request.setAttribute("webwork.request_uri", request.getRequestURI());

//set refresh target url
if (isPathUrl(finalLocation))
{
if (!finalLocation.startsWith("/"))
{
String actionPath = request.getServletPath();
String namespace = ServletDispatcher
.getNamespaceFromServletPath(actionPath);

if ((namespace != null) && (namespace.length() > 0))
{
finalLocation = namespace + "/" + finalLocation;
}
else
{
finalLocation = "/" + finalLocation;
}
}

// if the URL's are relative to the servlet context, append the servlet context path
if (prependServletContext && (request.getContextPath() != null)
&& (request.getContextPath().length() > 0))
{
finalLocation = request.getContextPath() + finalLocation;
}

finalLocation = response.encodeRedirectURL(finalLocation);
}

//LogMan.debug("Refreshing to finalLocation " + finalLocation);

//设置属性
OgnlValueStack stack = ActionContext.getContext().getValueStack();

PageMessage aPageMessage = (PageMessage)stack.findValue("pagemessage",PageMessage.class);

if(null!=aPageMessage)
{
aPageMessage.setMsgToURL(finalLocation);
}

dispatcher.forward(request, response);
}

//copy from ServletRedirectResult
private static boolean isPathUrl(String url)
{
// filter out "http:", "https:", "mailto:", "file:", "ftp:"
// since the only valid places for : in URL's is before the path specification
// either before the port, or after the protocol
return (url.indexOf(':') == -1);
}
}





3.信息提示页面

缺省为/WEB-INF/public/page/msgto.jsp,可以在webwork.properties里面配置"jscud.page.messageto",还可以通过配置文件配置.

可以根据自己需要更改页面内容.

<%@ page contentType="text/html; charset=GBK" %>
<%@ taglib uri="webwork" prefix="ww" %>

<html>
<head>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="Cache-Control" content="no-cache, must-revalidate">
<meta http-equiv="expires" content="0">

<meta http-equiv="Content-Type" content="text/html; charset=GBK">

<meta http-equiv="refresh" content="<ww:property value="pagemessage.msgToTime" />;URL=<ww:property value="pagemessage.msgToURL" />">

<title><ww:property value="pagemessage.msgTitle" /></title>
</head>
<body >
<div align=center>
<table width=90% border="0" cellspacing="0" cellpadding="0" align="center" bgcolor=#ffffff>
<tr valign="top">
<td width="2"> 　
</td>
<td width="5"></td>
<td colspan="3">
<center><br><br>
<table align="center" border="0" cellpadding="5" cellspacing="0" width="100%">
<tbody>
<tr>
<td><ww:property value="pagemessage.msgTitle" />
<hr noshade size="1" color="#808000">
</td>
</tr>
<tr>
<td><ww:property value="pagemessage.msgContent" /><br><br><br>
请稍后......<br>
</td>
</tr>
</tbody>
</table>
</center>

</td>
</tr>
</table>

</div>
</body>
</html>






4.配置示例

<result-types>
<result-type name="msgto" class="com.jscud.www.support.web.ServletMessageToResult" />
</result-types>


<action name="doAddCata" class="catagoryAction" method="doSet">
<result name="input" type="dispatcher">
<param name="location">/WEB-INF/jsp/news/catagory_add.jsp</param>
</result>
<result name="success" type="msgto">
<param name="location">/news/admin/admin.jspa</param>
</result>
</action>





5.Action中的代码示例



/**
* 增加/编辑类别
*
* @return 结果
*/
public String doSet()
{
//输入界面
if (null == catagory)
{
return INPUT;
}
catagoryManager.updateCatagory(getCatagory(), getWork());
//return goException("设置分类时发生了错误",ex);

setPageMessageProp("操作成功", "操作成功");

return SUCCESS;
}









以下代码放在基础Action里:(自己要做适当修改)


/**
* 设置信息提示的内容.
*
* @param sTitle
* @param sHintMsg
*/
protected void setPageMessageProp(String sTitle, String sHintMsg)
{
PageMessage apm = new PageMessage();
if ((null == sTitle) || (sTitle.equals("")))
{
sTitle = getText("core.errorhint.title.default");
}

apm.setMsgTitle(sTitle);
apm.setMsgContent(sHintMsg);

setPagemessage(apm);
}

/**
* 设置信息提示的参数.(转向)
*
* @param sTitle
* @param sHintMsg
* @param toURL
* @param nToTime
*/
protected void setPageMessageProp(String sTitle, String sHintMsg,int nToTime)
{
PageMessage apm = new PageMessage();

if ((null == sTitle) || (sTitle.equals("")))
{
sTitle = getText("core.errorhint.title.default");
}

apm.setMsgTitle(sTitle);
apm.setMsgContent(sHintMsg);
//apm.setMsgToURL(toURL);
apm.setMsgToTime(nToTime);

setPagemessage(apm);
}


public PageMessage getPagemessage()
{
return pagemessage;
}

public void setPagemessage(PageMessage pagemessage)
{
this.pagemessage = pagemessage;
}




ok,很简单,不是吗?