Clearing values from request in decode method

I am using a custom table paginator. In its decode method I have the next code to control whether next link is clicked:
String pLink = (String)requestMap.get("pLink" + clientId);
if ((pLink != null) && (!pLink.equals(""))) {
     if (pLink.equals("next")) {
     } else if (pLink.equals("previous")) {
}But the next sequence produces some problems:
1.     Initial page load.
2.     Click on next link.
3.     Table navigates ok to next page.
4.     Reload page (push F5).
5.     The previous click still remains in the request, so decode method think next link is pressed again.
6.     Application abnormal behaviour arises.
So, I am trying to clear the next_link key from the request, but next code throws an UnsupportedOperationException:
String pLink = (String)requestMap.get("pLink" + clientId);
if ((pLink != null) && (!pLink.equals(""))) {
     if (pLink.equals("next")) {
     } else if (pLink.equals("previous")) {
     requestMap.put("pLink" + clientId, "");
}Do any of you have some ideas?

Hey, where are you RaymondDeCampo, rLubke, BalusC ... the masters of JSF Universe?
;-)

Similar Messages

Clearing variable from Request object

Hi everyone,
After getting value from request.getParameter("var"), I want to clear this "var" variable from request scope. So that in the next coming statements if i again call the same request.getParameter("var") statement than it must return null
So how to handle this issue of clearing certain variable from request scope or flushing the whole request object

I don't know what you are trying to do but it sounds confused. I would suggest you read the parameter once, at the beginning of the code. Store it in a variable and use that variable as necessary. If you still need help then would you explain what you are trying to achieve here.

Passing values from HTML to JSP method,

Hello:
I am starting to wonder if what I am doing will ever work...
Ok, I am trying to avoid javascript. I have a drop-down list named "year" and I wish to call a JSP method that is defined/declared in the same JSP.
First, I want to pass the chosen option to the method and then store the name/value in a global variable.
Second, depending on what the user selects, I will get values from an array defined/initialized on page load AND display those values in another drop-down list.
As a test, and until now, I have done this. I am not passing anything yet, I just wanted to test this "fuzzy logic" I am having:
<%!
String currentYear;
private void showDaysInDDList()
currentYear = request.getparameter("year");
%>
Then on the HTML part of the page I have a drop-down list:
<html>
<head>
<title></title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body bgcolor="ffffcc">
<form method="POST" name="form1" action="left.jsp">
<select name="year" onchange="<%=showDaysInDDList()%>">
     <option></option>
     </select>
I am getting the following errors:
An error occurred at line: 105 in the jsp file: /p1/left.jsp
request cannot be resolved
....and regarding to the onchange="<%=showDaysInDDList()%>"> part I am getting the following:
An error occurred at line: 204 in the jsp file: /p1/left.jsp
The method print(boolean) in the type JspWriter is not applicable for the arguments (void)
In the action="left.jsp", left.jsp is the same page where the drop-down list and the method is. I am not sure if that is another error.
I will continue here with my coffee ... any help will be extremely appreciated !!..
I'll have to shut down my "asp.net mind" for a while..
I'll reply later,
MMS

Ok, this is a bit messy here. I don't know how much you've read up on JSP but you seem confused about some fundamentals to me. However, you mention that you've worked with ASP .net so I'm going to assume you do have some notion of how thing should work in general.
1. JSP is on the server-side and events like onchange that you've used take place on the client-side after the JSP/ servlet code has run and produced the HTML page. So calling your showDaysInDDList() will not work.
2. Are you sure you know how the declaration tags ( <%! %> ) work? When you normally write JSP code without these tags, all that code gets compiled into the service method of the corresponding servlet that the JSP gets turned into. But, you can declare your own methods and variables outside the service method by using these tags.
So what you're effectively doing is declaring
private String/ void showDaysInDDList()
}and followed by your usual _jspService()
public void _jspService(HttpServletRequest request,
   HttpServletResponse response)
     throws IOException, ServletException
}Now it may be clear, that the request object is not available in the showDaysInDDList() method by default; you'll either have to declare it ( not sure if it's good programming practice or not ) or pass the required parameters in the call.
3. Like you seem to have realized, that error about the printing of booleans was related to the return type of your method because <%= %> translates to out.println(); and since the argument was the method call, the return value was to be printed which here was a void ( not sure why it says boolean though :D ).
Read up on this introduction to JSPs http://java.sun.com/developer/onlineTraining/JSPIntro/contents.html, seems to be pretty good and covers everything in quick, short chunks.
Hope this helps.

Help with getting values from request. Very Strange!!

Hello,
My very strange problem is the following.
I have created three dynamic list boxes. When the user select
the first list box, the second becomes populated with stuff
from a database. The third becomes populated when the second
is selected. Now, I have used hidden values in order for
me to get the selected value from the first listbox. The
following code is my first listbox:
<SELECT NAME="resources" onChange="document.hiddenform.hiddenObject.value = this.option [this.selectedIndex].value; document.hiddenform.submit();">
<OPTION VALUE =""> Resource</OPTION>
<OPTION VALUE ="soil"> Soil </OPTION>
<OPTION VALUE ="water"> Water </OPTION>
<OPTION VALUE ="air"> Air </OPTION>
<OPTION VALUE ="plants"> Plants </OPTION>
<OPTION VALUE ="animals"> Animals </OPTION>
</SELECT>
I use the getRequest method to get the value of hiddenObject.
At this time I am able to get the value of hiddenObject to populate
the second list box.
But, when the user selects an item from the second list box
and the second form is also submitted,
I lose the value of hiddenObject. Why is this??
The code to populate my second listbox is the following:
<SELECT NAME ="res_categories" onChange="document.hiddenform2.hiddenObject2.value = this.options[this.selectedIndex].value; document.hiddenform2.submit(); ">
<OPTION VALUE ="" SELECTED> Category</OPTION>
Here I access a result set to populate the list box.
Please help!!

Form parameters are request-scoped, hence the request.getParameter("hiddenObject"); call after the submission of the second form returns a null value because the hiddenObject parameter does not exist within the second request.
A solution would be to add a hiddenObject field to your second form and alter the onChange event for res_categories to read
document.hiddenform2.hiddenObject.value=document.1stvisibleformname.resources.option[document.1stvisibleformname.resources.selectedIndex].value;
document.hiddenform2.hiddenObject2.value = this.options[this.selectedIndex].value;
document.hiddenform2.submit();You will then come across a similar problem with your third drop-down if indeed you need to resubmit the form...
A far better approach would be to create a session scoped bean, and a servlet to handle these requests. Then when the servlet is called, it would set the value of the bean property, thus making it available for this request, and all subsequent requests within the current session. This approach would eliminate the need for the clunky javascript, making your application far more stable.

Get all values from request.getParameter

In ASP, I can do something like that...
For each item in Request.Form
Response.write "Name is:" & item & " value is:" & Request(item)
Next
How about in JSP? How do i get the names and values of the form using a loop?

You can use request.getParameterNames() which will return an enumeration, then you can iterate through the enumeration and use request.getParameterValue(String paramName) method to get the values.

Returning several values from a C native method

Hi,
I need to return 3 values from a native methode : an int (the return code), a string of variable length and a double.
In pure C, my function would be defined as "int f ( char* s, double* d)", and I would "malloc" the string into the calling function, then copy my string to "s" and use "*d" to return the double...
Is there a way to do that with JNI? I found some examples where the native function returns only one parameterlike: "return(*env)->NewStringUTF(env, buffer);" But I didn't find examples where the native function returns several parameters, including a string.
Thanks in advance!
JM

This really has nothing to do with JNI.
You have a method, and you want to return more than one type of value.
The following solutions are possible.
1. Return an array that contains all the values (actual return value.)
2. Return an object that contains all the values (actual return value.)
3. Use an array via the parameter list and fill in a value.
4. Use an object via the parameter list and fill in the values.

How can I get the variable with the value from Thread's run method

We want to access a variable from the run method of a Thread externally in a class or in a method. Even though I make the variable as public /public static, I could get the value till the end of the run method only. After that scope of the variable gets lost resulting to null value in the called method/class..
How can I get the variable with the value?
This is sample code:
public class SampleSynchronisation
     public static void main(String df[])
sampleThread sathr= new sampleThread();
sathr.start();
System.out.println("This is the value from the run method "+sathr.x);
/* I should get:
Inside the run method
But I get only:
Inside*/
class sampleThread extends Thread
     public String x="Inside";
     public void run()
          x+="the run method";
NB: if i write the variable in to a file I am able to read it from external method. This I dont want to do

Your main thread continues to run after the sathr thread is completed, consequently the output is done before the sathr thread has modified the string. You need to make the main thread pause, this will allow sathr time to run to the point where it will modify the string and then you can print it out. Another way would be to lock the object using a synchronized block to stop the main thread accessing the string until the sathr has finished with it.

Capture Return Value from Contextual Events Subscriber Method

Hi
I was wondering if anyone knew whether you could capture the return value from a method exposed as a subscriber for a contextual event?
Requirement: We have 2 bounded task flows (parent-child) with the child task flow embedded as a region in a view activity in the parent task flow. Based on an action in the parent task flow we raise a contextual event which calls an application module method exposed as a data control within the child task flow. We need to be able to capture the return value from the method on the managed bean.
Example method within child task flow application module:
public String contextualEventSub(){
Return "Y";
So here we would like to capture String value when the event is raised by the event producer (parent task flow action).
Within the Event Map on the page definition of the parent task flow view activity it is possible to set parameters to pass to the subscriber but it’s not obvious where you can capture the return value.
Many thanks!
Technology:
ADF 11.1.1.7 – ADFbc with ADF task flows and page fragments

Check this URL it may help you
One size doesn't fit all: JDev 11g: Programmatic Contextual Events

Unable to retrieve values from request.getAttribute()

I had a JSP file called targetJspPage.jsp that contains the following statement within a set of <form> tags:
<% request.setAttribute "url","/myProj/targetJspPage.jsp");%>This information is then submitted to a servlet using POST method which will use a RequestDispatcher to retrieve the the url from the request attribute that I had set just now. The statement is as follows:
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher((String)request.getAttribute("url"));
if (dispatcher != null)
dispatcher.forward(request, response);The purpose of this procedure is to let the servlet know which JSP file it is suppose to forward the processed results. The url is always the url of the page that is calling the servlet. Eg. In this case, my JSP file is targetJspPage.jsp which resides in myProj folder. So, in this JSP file, the url set for the servlet will be /myProj/targetJspPage.jsp. But my problem now is that the (String)request.getAttribute("url") statement in the servlet always returns null. Why is that so?
This type of question was asked numerous times in the forums but the solutions aren't working. I do not want to use a session to store the value. However, I also tried using session before and the result is the same.

Hi Sad,
1.
Is it possible that you post the codes that we can see clearly what is going on? (If possible only).
(Unless I'm wrong, it may be that the request.setAttribute is used to pass object on the server side only, ie you can't use the request.setAttribute to keep data like the session object during the client-server trips of request/response.
The fact that you get null for (String)request.getAttribute("url") is because the Browser send a new request object which is different from the old one (request.setAttribute which is gone once we down the client)
(2. I want to learn too, and hope some one will find a solution for you)
-- Paul.

Reading Null Values From Request Object

For a proof-of-concept, I wrote a mini program that has 2 files. File #1 is main.html. There's a javascript function called addNewRowToThisTable that isn't displayed but it basically allows the user to create as many rows in the table as user desires. When the "Submit" button is clicked the file ReadIt.jsp is called and it's supposed to display on the first and last names of the people who had the checkbox for that row checked. The best way to illustrate the problem I'm having is through an example. Let's say there are 3 rows:
[x] Alan Anderson [Add New Row]
[ ] Bob Brady [Add New Row]
[x] Carl Chadwick [Add New Row]
[Submit]
Let's assume that only rows 1 and 3 are clicked. After the form is submitted the JSP will print...
firstNameArr .length = 3
lastNameArr .length = 3
isSelectedArr.length = 2
firstNameArr[0] = Alan
lastNameArr[0] = Anderson
firstNameArr[1] = Bob
lastNameArr[1] = Brady
Unfortunately firstNameArr[1] and lastNameArr[1] should be "Carl", and "Chadwick" respectively. I know the reason why it's failing is because my program relies on the array index of the "isSelected" field to perfectly match up with the "firstName" and "lastName" fields. It's unreliable because if the checkbox for a row is not checked then it won't show up in the JSP String array isSelectedArr. I'm not really sure how to get around this problem. I have 2 ideas at the beginning of solutions but I'm not sure how to follow through on either and I'm also not sure if either is the proper approach to take. My guesses are...
1) There's some way in JSP to use "getParameterValues('isSelected')" to retrieve the full array of "isSelected" items regardless of whether or not they're checked. That would guarantee that my arrays would match up correctly. Unfortunately, I haven't been able to find this.
2) Maybe I can put in some sort of ID in the "isSelected" field that would relate the checkbox to the rest of the data in the row. The problem with this is that I've got a dynamic # of rows due to my addNewRowToThisTable method.
So the bottom line is that I'm thoroughly stumped. If anyone can offer advice I'd be very grateful.
main.html
<html><head><title></title></head><body>
<form method="get" action="ReadIt.jsp">
<table>
<tr>
     <td><input type="checkbox" name="isSelected" /></td>
     <td><input type="text" name="firstName" /> </td>
     <td><input type="text" name="lastName" /></td>
     <td><input type="button" value="Add New Row" onClick="addNewRowToThisTable(this)" />
</tr>
<tr>
     <td colspan=4><input type="submit" value="submit"></input></td>
</tr>
</table>
</form>
</body></html>
ReadIt.jsp
<%
String[] isSelectedArr = request.getParameterValues("isSelected");
String[] firstNameArr = request.getParameterValues("firstName");
String[] lastNameArr = request.getParameterValues("lastName");
if (firstNameArr != null) System.out.println("firstNameArr .length = " + firstNameArr .length);
if (lastNameArr != null) System.out.println("lastNameArr .length = " + lastNameArr .length);
if (isSelectedArr != null) {
     System.out.println("isSelectedArr.length = " + isSelectedArr.length);
     for (int i=0; i < isSelectedArr.length; i++) {
          System.out.println("firstNameArr["+i+"] = " + firstNameArr);
          System.out.println("lastNameArr["+i+"] = " + firstNameArr[i]);
%>

it's sort of a kludge, but try this:
your javascript function adds new for fields that get submitted to the servlet. name the checkboxes uniquely with a patterm with said function, say isSelected-1, isSelected-2, isSelected-3... now also name the first and last name fields the same way. fname-1, fname-2, fname-3... lname-1,lname-2,lname-3.
when you get to the page that is supposed to match them up, go through all the request parameters looking for those that start with "isSelected-" take the last char (the index), convert it to an int, and then from your request do:
String first = request.getParameter("fname-" + indexThatWasFound);
          String last = request.getParameter("lname-" + indexThatWasFound);in looping over the request for each index recovered from the searching of the request for the isSelected-n values, you will get the matching first and last name.
I TOLD you it was a kludge.

Store value from request message to be processed in response mapping

Hi,
I have the following synchronous scenario:
R/3 (ABAP Proxy) <> XI/PI <> 3rd party Web Service
I need to reference a value in the sender (request) message in the response mapping.
For example:
A request with a user ID is received from R/3 to XI/PI. I want to store the user ID in the request message. A response is received from the web service. I then want to use the user ID in the response mapping.
I believe XI/PI can meet this requirement with a BPM using container or possibly using a custom table to store Message GUID and the variable value in the request message mapping.
Are there any other methods that can be used to meet this scenario?
Thanks and regards,
Duke

Hi All,
This is the first time I've encountered such a requirement. Most of the time we create our own programs that call the sender proxy, so to interogate the results and call another proxy would be the ideal solution. But, in this case the standard LSO process controls the execution of the proxy. We may look into doing an enhancement to the standard code, but I was looking for a way we can do this in PI with minimal effort.
As Stefan stated, I also noticed that the DynamicConfiguration is emptied in the response.
We will explore the use of BPM, but from what I can see, utilizing a custom table with the runtime constant MESSAGE_ID may be the simplest solution in PI.
Thanks and regards,
Duke

Problem getting arraylist values from request

Hi All,
I am trying to display the results of a search request.
In the jsp page when I add a scriplet and display the code I get the values else it returns empty as true.Any help is appreciated.
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %>
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
     <%@ include file="/includes/header.jsp"%>
     <title>Research Results</title>
</head>
<body>
<div class="ui-widget ui-widget-content">
    <%
    ArrayList<Research> research = (ArrayList<Research>) request.getAttribute("ResearchResults");
     Iterator iterator = research.iterator();
          while(iterator.hasNext()){
          Research r = (Research) iterator.next();
          out.println("Result Here"+r.getRequesterID());
          out.println("Result Here"+r.getStatus());
    %>
     <form>
     <c:choose>
     <c:when test='${not empty param.ResearchResults}'>
     <table cellspacing="0" cellpadding="0" id="research" class="sortable">
     <h2>RESEARCH REQUESTS</h2>
               <tr>
               <th><a href="#">RESEARCH ID</a></th>
               <th><a href="#">REQUESTOR NAME</a></th>
               <th><a href="#">DUE DATE</a></th>
               <th><a href="#">REQUEST DATE</a></th>
               <th><a href="#">CLIENT</a></th>
               <th><a href="#">STATUS</a></th>
               <th><a href="#">PRIORITY</a></th>
               </tr>
          <c:forEach var="row" items="${param.ResearchResults}">
                    <tr title="">
                         <td id="researchID">${row.RESEARCH_ID}</td>
                         <td>${row.REQUESTER_FNAME} ${row.REQUESTER_LNAME}</td>
                         <td><fmt:formatDate pattern="MM/dd/yyyy" value="${row.DUE_DATE}"/></td>
                         <td><fmt:formatDate pattern="MM/dd/yyyy" value="${row.CREATED_DATE}"/></td>
                         <td>${row.CLIENT}</td>
                         <td>
                         <c:choose>
                           <c:when test="${row.STATUS=='10'}">New Request</c:when>
                           <c:when test="${row.STATUS=='20'}">In Progress</c:when>
                           <c:when test="${row.STATUS=='30'}">Completed</c:when>
                          </c:choose>
                         </td>
                         <td>
                         <c:choose>
                           <c:when test="${row.PRIORITY=='3'}">Medium</c:when>
                           <c:when test="${row.PRIORITY=='2'}">High</c:when>
                           <c:when test="${row.PRIORITY=='1'}">Urgent</c:when>
                          </c:choose>
                         </td>
                         </tr>
          </c:forEach>
     </table>
     </c:when>
     <c:otherwise>
     <div class="ui-state-highlight ui-corner-all">
               <p><b>No results Found. Please try again with a different search criteria!</b> </p>
          </div>
     </c:otherwise>
     </c:choose>
     </form>
          <%@ include file="/includes/footer.jsp"%>
     </div>
     </body>
</html>

What is ResearchResults?
Is it a request parameter or is it a request attribute?
Parameters and attributes are two different things.
Request parameters: the values submitted from the form. Always String.
Request attributes: objects stored into scope by your code.
They are also accessed slightly differently in EL
java syntax == EL syntax
request.getParameter("myparameter") == ${param.myparameter}
request.getAttribute("myAttribute") == ${requestScope.myAttribute}
You are referencing the attribute in your scriptlet code, but the parameter in your JSTL/EL code.
Which should it be?
cheers,
evnafets

Geting null values from request

hi!
i m producing this code through out.println() method in my page and then using java script
i am submiting this page to another page
<td width="56%"><textarea name="question_no_1"></textarea></td>
<input name="question_no_1_radio1" type="radio" value="radio"></td>
<td width="59%"> <textarea name="question_no_1_ans1"></textarea></td>
<input type="radio" name="question_no_1_radio2" value="radio"></td>
<td><textarea name="question_no_1_ans2"></textarea></td>
<input type="radio" name="question_no_1_radio3" value="radio"></td>
<td><textarea name="question_no_1_ans3"></textarea></td>
<input name="question_no_1_radio4" type="radio" value="radio"></td>
<td><textarea name="question_no_1_ans4"></textarea></td>
but when i submit it to the other page and try to retrieve value of parameter "question_no_1"
through the bellow statement it shows a null value but i have given a value previously by
typing a question in it
System.out.println("the Body Of The First Question Is "+request.getParameter("question_no_1"));
can anybody help me what is going on here.
also if i try to normaly submit first page (ie <form="form1" method="post" action="other_jsp_page.jsp"> ) then the statement in the next page gives me the correct value but
i have to submit the first paper through java script.
if u want to see full detail of my code then go to the following link
http://forum.java.sun.com/thread.jsp?thread=309254&forum=45&message=1237097
thanx in advance

OK, your problem is that you are not submmiting the values to the other page. When you do the
--> document.forms[0].submit();
in JavaScript, the form has to action defined
--> <form name="form1" method="" action="">
So, the page does nothing. The line following the submit just changes the location of the page, IT DOES NOT POST the values.
One solutions is the following:
1.- define an action for your form:
<form name="form1" method="POST" action="'save_paper.jsp">
2.- Then create a JavaScript function that validates the fields and simply return "true" if the form is correct, and false if there is a problem (just a little modification of the one you have).
3.- Then modify your submit button:
Instead of:
<input type="button" name="Save" value="Save" onClick="validateField()">
Try:
<input type="SUBMIT" value="Save" onclick="validateField();">

How to get Int value from request.getParameter()?

Hi all,
I have a integer value which is passed from one page to another page.
i am geting this value in the next page using
request.getParameter().
Eg.
Suppose value of "i" in page1 is 32, i pass this as hidden variable to next page.
<input type="hidden" Value="<%=i%>" NAME="limit">
in page2, i fethch this value to a variable by name "limit"
String limit=request.getParameter("limit");
but, since value stored in limit is int, i can't assign it to string.
i can't use request.getParameter for int values.
How to solve my problem.
I know it is simple,
Pls. help me
Regards
ASh
String limit=request.getParameter("limit");

String limitSTR = request.getParameter("limit");
int limit = -1;
if (limitSTR != null) limit = Integer.parseInt(limitSTR);

How to trap null return values from getters when using Method.invoke()?

Hi,
I am using Method.invoke() to access getters in an Object. I need to know which getters return a value and which return null. However, irrespective of the actual return value, I am always getting non-null return value when using Method.invoke().
Unfortunately, the API documentation of Method.invoke() does not specify how it treats null return values.
Can someone help?
Thanks

What do you get as a result?I think I know what the problem is.
I tested this using following and it worked fine:
public class TestMethodInvoke {
public String getName() {
return null;
public static void main(String args[]) throws SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException {
Object o = new TestMethodInvoke();
Class cls = o.getClass();
Method m = cls.getMethod("getName", (Class[]) null);
Object result = m.invoke(o, (Object[])null);
if (result == null) {
System.err.println("OK: Return value was null as expected");
else {
System.err.println("FAILED: Return value was NOT null as expected");
However, when I use the same technique with an EJB 3.0 Entity class, the null return value is not returned. Instead, I get a String() object. Clearly, the problem is the the EJB 3.0 implementation (Glassfish/Toplink) which is manipulating the getters.
Regards
Dibyendu

Clearing values from request in decode method

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