I'm totally new in jsp/servlet and working with an application that I have many jsp pages and servlet.
In the first jsp page I choose a customer.
<select id ="sel" name="customer">
<option>customer1</option>
<option>customer2</option>
<option>customer3</option>
<option>customer4</option>
</select>
In the second jsp page it shows me the menu related to this customer(for example I choose configuration and goes to the third jsp page )
<% HttpSession session = request.getSession(true);
String chos_cust=request.getParameter("customer");
session.setAttribute("cust_menu",chos_cust); %>
....
<%= session.getAttribute("cust_menu")%>
In the third jsp page I choose cateories related to this customer(there are many categories for each customer)
An sql query runs here to show categories as radio buttons:
<input type="radio" name="chos_gr" value="${groups.group_name}"checked > ${groups.group_name}
In the forth jsp page according to the chosen category it will show subcategories. In this jsp page I have three div
in html form with hidden type.In the first div list of products has been shown , the second div is for adding a product and in the last div products can be deleted.
String config_gr = request.getParameter("chos_gr");
session.setAttribute("config_menu",config_gr);
I have used a servlet to do these operations(add, delete). It works well but when I add or delete a product and use requestDispstcher/forward in servlet to back to the last jsp to see the result(list of products) it
shows null for category and nothing in list of products.
If I should return the value of category in the servlet to the last jsp?
Could someone tell me what the problem is?
I can't add a comment for this post. As #underdog suggested I used ${sessionScope.config_menu} in the last jsp and it still shows null for category. It's weird because I get the customer value when I return to the last jsp to see the result but nothing for category.
You are adding all the object/values in a session attribute. With request dispatcher you forward the flow to a jsp with request & response objects. The request object contains no info of the customer you have set in the session object.
In the jsp try accessing the values from the session scope.
${sessionScope.config_menu} would give you the desired output.
Instead of using a response.sendRedirect(url), consider using following:
RequestDispatcher dispatcher = request.getRequestDispatcher(url);
dispatcher.forward(request,response);
Above code with the getRequestDispatcher() will allow you to include your calling servlet's request by using dispatcher.forward, which will include the session attributes you were missing.
[NOTE: OP was already doing the above]
[UPDATE]
Based on the way you were suggesting to code certain parameters in <input type="hidden" name="myfield"> fields, I suspect, you did nothing else to store the values. Which means, the first time around, they might have been set using the parameters from the previous request, but when using the dispatcher.forward, this did not happen.
For fields to be initiated with the appropriate value, they require to be made available either through request parameters (e.g. GET parameters, encoded in the URL), or otherwise set within the JSP itself trough <input type="hidden" value="${whatever}" name="myfield"> or similar code. I am also missing that part of the code to be able to validate.
Using a dispatcher.forward(), you might not have required parameters set.
I would like to set a value of bean from another bean once a page is displayed. The target dataTable is included because it is also used in another context.
Like I said before, there are two beans involved:
bean1 'gets' a parameter, will load an object and display some properties.
bean2 is the bean that is responsible for the filtering / search in the dataTable.
relevant parts:
<f:metadata>
<f:viewParam name="objectId" value="#{bean1.objectId}" />
</f:metadata>
<!-- resolving works -->
#{bean1.object.name}
included search:
<p:dataTable>...<p:inputText value="#{bean2.value}">...</p:dataTable>
How to assign (a substring of) bean1.object.name to the value of the input text once at page request but keep the existing value attribute of the field? I don't want to mess up the included page but would prefer to solve it "outside" in my including jsf/xhtml file.
The best way to do this is using javascript.
Define a input hidden tag to hold the value of #{bean1.object.name}.
Now in javascript get the value of this field using document.getElementById("").value
Take the substring and assign to input text field using javascript.
Sometimes, when using <h:commandLink>, <h:commandButton> or <f:ajax>, the action, actionListener or listener method associated with the tag are simply not being invoked. Or, the bean properties are not updated with submitted UIInput values.
What are the possible causes and solutions for this?
Introduction
Whenever an UICommand component (<h:commandXxx>, <p:commandXxx>, etc) fails to invoke the associated action method, or an UIInput component (<h:inputXxx>, <p:inputXxxx>, etc) fails to process the submitted values and/or update the model values, and you aren't seeing any googlable exceptions and/or warnings in the server log, also not when you configure an ajax exception handler as per Exception handling in JSF ajax requests, nor when you set below context parameter in web.xml,
<context-param>
<param-name>javax.faces.PROJECT_STAGE</param-name>
<param-value>Development</param-value>
</context-param>
and you are also not seeing any googlable errors and/or warnings in browser's JavaScript console (press F12 in Chrome/Firefox23+/IE9+ to open the web developer toolset and then open the Console tab), then work through below list of possible causes.
Possible causes
UICommand and UIInput components must be placed inside an UIForm component, e.g. <h:form> (and thus not plain HTML <form>), otherwise nothing can be sent to the server. UICommand components must also not have type="button" attribute, otherwise it will be a dead button which is only useful for JavaScript onclick. See also How to send form input values and invoke a method in JSF bean and <h:commandButton> does not initiate a postback.
You cannot nest multiple UIForm components in each other. This is illegal in HTML. The browser behavior is unspecified. Watch out with include files! You can use UIForm components in parallel, but they won't process each other during submit. You should also watch out with "God Form" antipattern; make sure that you don't unintentionally process/validate all other (invisible) inputs in the very same form (e.g. having a hidden dialog with required inputs in the very same form). See also How to use <h:form> in JSF page? Single form? Multiple forms? Nested forms?.
No UIInput value validation/conversion error should have occurred. You can use <h:messages> to show any messages which are not shown by any input-specific <h:message> components. Don't forget to include the id of <h:messages> in the <f:ajax render>, if any, so that it will be updated as well on ajax requests. See also h:messages does not display messages when p:commandButton is pressed.
If UICommand or UIInput components are placed inside an iterating component like <h:dataTable>, <ui:repeat>, etc, then you need to ensure that exactly the same value of the iterating component is been preserved during the apply request values phase of the form submit request. JSF will reiterate over it to find the clicked link/button and submitted input values. Putting the bean in the view scope and/or making sure that you load the data model in #PostConstruct of the bean (and thus not in a getter method!) should fix it. See also How and when should I load the model from database for h:dataTable.
If UICommand or UIInput components are included by a dynamic source such as <ui:include src="#{bean.include}">, then you need to ensure that exactly the same #{bean.include} value is preserved during the view build time of the form submit request. JSF will reexecute it during building the component tree. Putting the bean in the view scope and/or making sure that you load the data model in #PostConstruct of the bean (and thus not in a getter method!) should fix it. See also How to ajax-refresh dynamic include content by navigation menu? (JSF SPA).
The rendered attribute of the component and all of its parents and the test attribute of any parent <c:if>/<c:when> should not evaluate to false during the apply request values phase of the form submit request. JSF will recheck it as part of safeguard against tampered/hacked requests. Storing the variables responsible for the condition in a #ViewScoped bean or making sure that you're properly preinitializing the condition in #PostConstruct of a #RequestScoped bean should fix it. The same applies to the disabled and readonly attributes of the component, which should not evaluate to true during apply request values phase. See also JSF CommandButton action not invoked, Form submit in conditionally rendered component is not processed, h:commandButton is not working once I wrap it in a <h:panelGroup rendered> and Force JSF to process, validate and update readonly/disabled input components anyway
The onclick attribute of the UICommand component and the onsubmit attribute of the UIForm component should not return false or cause a JavaScript error. There should in case of <h:commandLink> or <f:ajax> also be no JS errors visible in the browser's JS console. Usually googling the exact error message will already give you the answer. See also Manually adding / loading jQuery with PrimeFaces results in Uncaught TypeErrors.
If you're using Ajax via JSF 2.x <f:ajax> or e.g. PrimeFaces <p:commandXxx>, make sure that you have a <h:head> in the master template instead of the <head>. Otherwise JSF won't be able to auto-include the necessary JavaScript files which contains the Ajax functions. This would result in a JavaScript error like "mojarra is not defined" or "PrimeFaces is not defined" in browser's JS console. See also h:commandLink actionlistener is not invoked when used with f:ajax and ui:repeat.
If you're using Ajax, and the submitted values end up being null, then make sure that the UIInput and UICommand components of interest are covered by the <f:ajax execute> or e.g. <p:commandXxx process>, otherwise they won't be executed/processed. See also Submitted form values not updated in model when adding <f:ajax> to <h:commandButton> and Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes.
If the submitted values still end up being null, and you're using CDI to manage beans, then make sure that you import the scope annotation from the correct package, else CDI will default to #Dependent which effectively recreates the bean on every single evaluation of the EL expression. See also #SessionScoped bean looses scope and gets recreated all the time, fields become null and What is the default Managed Bean Scope in a JSF 2 application?
If a parent of the <h:form> with the UICommand button is beforehand been rendered/updated by an ajax request coming from another form in the same page, then the first action will always fail in JSF 2.2 or older. The second and subsequent actions will work. This is caused by a bug in view state handling which is reported as JSF spec issue 790 and currently fixed in JSF 2.3. For older JSF versions, you need to explicitly specify the ID of the <h:form> in the render of the <f:ajax>. See also h:commandButton/h:commandLink does not work on first click, works only on second click.
If the <h:form> has enctype="multipart/form-data" set in order to support file uploading, then you need to make sure that you're using at least JSF 2.2, or that the servlet filter who is responsible for parsing multipart/form-data requests is properly configured, otherwise the FacesServlet will end up getting no request parameters at all and thus not be able to apply the request values. How to configure such a filter depends on the file upload component being used. For Tomahawk <t:inputFileUpload>, check this answer and for PrimeFaces <p:fileUpload>, check this answer. Or, if you're actually not uploading a file at all, then remove the attribute altogether.
Make sure that the ActionEvent argument of actionListener is an javax.faces.event.ActionEvent and thus not java.awt.event.ActionEvent, which is what most IDEs suggest as 1st autocomplete option. Having no argument is wrong as well if you use actionListener="#{bean.method}". If you don't want an argument in your method, use actionListener="#{bean.method()}". Or perhaps you actually want to use action instead of actionListener. See also Differences between action and actionListener.
Make sure that no PhaseListener or any EventListener in the request-response chain has changed the JSF lifecycle to skip the invoke action phase by for example calling FacesContext#renderResponse() or FacesContext#responseComplete().
Make sure that no Filter or Servlet in the same request-response chain has blocked the request fo the FacesServlet somehow. For example, login/security filters such as Spring Security. Particularly in ajax requests that would by default end up with no UI feedback at all. See also Spring Security 4 and PrimeFaces 5 AJAX request handling.
If you are using a PrimeFaces <p:dialog> or a <p:overlayPanel>, then make sure that they have their own <h:form>. Because, these components are by default by JavaScript relocated to end of HTML <body>. So, if they were originally sitting inside a <form>, then they would now not anymore sit in a <form>. See also p:commandbutton action doesn't work inside p:dialog
Bug in the framework. For example, RichFaces has a "conversion error" when using a rich:calendar UI element with a defaultLabel attribute (or, in some cases, a rich:placeholder sub-element). This bug prevents the bean method from being invoked when no value is set for the calendar date. Tracing framework bugs can be accomplished by starting with a simple working example and building the page back up until the bug is discovered.
Debugging hints
In case you still stucks, it's time to debug. In the client side, press F12 in webbrowser to open the web developer toolset. Click the Console tab so see the JavaScript conosle. It should be free of any JavaScript errors. Below screenshot is an example from Chrome which demonstrates the case of submitting an <f:ajax> enabled button while not having <h:head> declared (as described in point 7 above).
Click the Network tab to see the HTTP traffic monitor. Submit the form and investigate if the request headers and form data and the response body are as per expectations. Below screenshot is an example from Chrome which demonstrates a successful ajax submit of a simple form with a single <h:inputText> and a single <h:commandButton> with <f:ajax execute="#form" render="#form">.
(warning: when you post screenshots from HTTP request headers like above from a production environment, then make sure you scramble/obfuscate any session cookies in the screenshot to avoid session hijacking attacks!)
In the server side, make sure that server is started in debug mode. Put a debug breakpoint in a method of the JSF component of interest which you expect to be called during processing the form submit. E.g. in case of UICommand component, that would be UICommand#queueEvent() and in case of UIInput component, that would be UIInput#validate(). Just step through the code execution and inspect if the flow and variables are as per expectations. Below screenshot is an example from Eclipse's debugger.
If your h:commandLink is inside a h:dataTable there is another reason why the h:commandLink might not work:
The underlying data-source which is bound to the h:dataTable must also be available in the second JSF-Lifecycle that is triggered when the link is clicked.
So if the underlying data-source is request scoped, the h:commandLink does not work!
While my answer isn't 100% applicable, but most search engines find this as the first hit, I decided to post it nontheless:
If you're using PrimeFaces (or some similar API) p:commandButton or p:commandLink, chances are that you have forgotten to explicitly add process="#this" to your command components.
As the PrimeFaces User's Guide states in section 3.18, the defaults for process and update are both #form, which pretty much opposes the defaults you might expect from plain JSF f:ajax or RichFaces, which are execute="#this" and render="#none" respectively.
Just took me a looong time to find out. (... and I think it's rather unclever to use defaults that are different from JSF!)
I would mention one more thing that concerns Primefaces's p:commandButton!
When you use a p:commandButton for the action that needs to be done on the server, you can not use type="button" because that is for Push buttons which are used to execute custom javascript without causing an ajax/non-ajax request to the server.
For this purpose, you can dispense the type attribute (default value is "submit") or you can explicitly use type="submit".
Hope this will help someone!
Got stuck with this issue myself and found one more cause for this problem.
If you don't have setter methods in your backing bean for the properties used in your *.xhtml , then the action is simply not invoked.
I recently ran into a problem with a UICommand not invoking in a JSF 1.2 application using IBM Extended Faces Components.
I had a command button on a row of a datatable (the extended version, so <hx:datatable>) and the UICommand would not fire from certain rows from the table (the rows that would not fire were the rows greater than the default row display size).
I had a drop-down component for selecting number of rows to display. The value backing this field was in RequestScope. The data backing the table itself was in a sort of ViewScope (in reality, temporarily in SessionScope).
If the row display was increased via the control which value was also bound to the datatable's rows attribute, none of the rows displayed as a result of this change could fire the UICommand when clicked.
Placing this attribute in the same scope as the table data itself fixed the problem.
I think this is alluded to in BalusC #4 above, but not only did the table value need to be View or Session scoped but also the attribute controlling the number of rows to display on that table.
I had this problem as well and only really started to hone in on the root cause after opening up the browser's web console. Until that, I was unable to get any error messages (even with <p:messages>). The web console showed an HTTP 405 status code coming back from the <h:commandButton type="submit" action="#{myBean.submit}">.
In my case, I have a mix of vanilla HttpServlet's providing OAuth authentication via Auth0 and JSF facelets and beans carrying out my application views and business logic.
Once I refactored my web.xml, and removed a middle-man-servlet, it then "magically" worked.
Bottom line, the problem was that the middle-man-servlet was using RequestDispatcher.forward(...) to redirect from the HttpServlet environment to the JSF environment whereas the servlet being called prior to it was redirecting with HttpServletResponse.sendRedirect(...).
Basically, using sendRedirect() allowed the JSF "container" to take control whereas RequestDispatcher.forward() was obviously not.
What I don't know is why the facelet was able to access the bean properties but could not set them, and this clearly screams for doing away with the mix of servlets and JSF, but I hope this helps someone avoid many hours of head-to-table-banging.
I had lots of fun debugging an issue where a <h:commandLink>'s action in richfaces datatable refused to fire. The table used to work at some point but stopped for no apparent reason. I left no stone unturned, only to find out that my rich:datatable was using the wrong rowKeyConverter which returned nulls that richfaces happily used as row keys. This prevented my <h:commandLink> action from getting called.
One more possibility: if the symptom is that the first invocation works, but subsequent ones do not, you may be using PrimeFaces 3.x with JSF 2.2, as detailed here: No ViewState is sent.
I fixed my problem with placing the:
<h:commandButton class="btn btn-danger" value = "Remove" action="#{deleteEmployeeBean.delete}"></h:commandButton>
In:
<h:form>
<h:commandButton class="btn btn-danger" value = "Remove" action="#{deleteEmployeeBean.delete}"></h:commandButton>
</h:form>
This is the solution, which is worked for me.
<p:commandButton id="b1" value="Save" process="userGroupSetupForm"
actionListener="#{userGroupSetupController.saveData()}"
update="growl userGroupList userGroupSetupForm" />
Here, process="userGroupSetupForm" atrribute is mandatory for Ajax call. actionListener is calling a method from #ViewScope Bean. Also updating growl message, Datatable: userGroupList and Form: userGroupSetupForm.
<ui:composition>
<h:form id="form1">
<p:dialog id="dialog1">
<p:commandButton value="Save" action="#{bean.method1}" /> <!--Working-->
</p:dialog>
</h:form>
<h:form id="form2">
<p:dialog id="dialog2">
<p:commandButton value="Save" action="#{bean.method2}" /> <!--Not Working-->
</p:dialog>
</h:form>
</ui:composition>
To solve;
<ui:composition>
<h:form id="form1">
<p:dialog id="dialog1">
<p:commandButton value="Save" action="#{bean.method1}" /> <!-- Working -->
</p:dialog>
<p:dialog id="dialog2">
<p:commandButton value="Save" action="#{bean.method2}" /> <!--Working -->
</p:dialog>
</h:form>
<h:form id="form2">
<!-- .......... -->
</h:form>
</ui:composition>
I have a problem with RichFaces and creating lists of links. If you attempt to use any type of commandLink inside a list (I've tried ui:repeat and rich:list) the action on that link is not called. I've also tried commandButton and the a4j variations of those. I'm using JSF 2, RichFaces 4 on Jboss 6.
<rich:list var="venue" value="#{searchManager.results}" type="definitions" stateVar="status">
<h:form>
<h:commandLink value="CLICK IT" immediate="true" action="#{score.selectVenue}" />
</h:form>
</rich:list>
The position of the form also doesn't matter.
<h:form>
<rich:list var="venue" value="#{searchManager.results}" type="definitions" stateVar="status">
<h:commandLink value="CLICK IT" immediate="true" action="#{score.selectVenue}" />
</rich:list>
</h:form>
If I just have the link by itself (no list) it works.
Any help would be greatly appreciated.
When you click a command link or press a command button to submit a form, JSF will during the apply request values phase scan the component tree for the command link/button in question so that it can find the action expression associated with it, which is in your case #{score.selectVenue}.
However to be able to ever reach that, you would need to ensure that #{searchManager.results} returns exactly the same list as it did when the form was displayed. Because with an empty result list, there would be no command link/button in the view at all during the apply request values phase of the form submit.
Your #{searchManager} bean seems to be request scoped. Request scoped beans have a lifetime of exactly one request-response cycle. So when you submit the form, you'll get a brand new and another instance of the request scoped bean than it was when the form was displayed. The results property seems not to be preserved during (post)construction of the bean and thus remains empty. So JSF cannot find the command link/button in question and thus cannot find the action expression associated with it and thus cannot invoke it.
As you're using JSF2, an easy fix is to place the bean in the view scope. This way the bean will live as long as you're submitting and navigating to exactly the same view by returning null or void in action methods.
#ManagedBean
#ViewScoped
public class SearchManager {
// ...
}
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated
Is there any way to set request attributes (not parameters) when a form is posted?
The problem I am trying to solve is: I have a JSP page displaying some data in a couple of dropdown lists. When the form is posted, my Controller servlet processes this request (based on the parameters set/specified in the form) and redirects to the same JSP page that is supposed to display addition details. I now want to display the same/earlier data in the dropdown lists without having to recompute or recalculate to get that same data.
And in the said JSP page, the dropdown lists in the form are populated by data that is specified through request attributes. Right now, after the Form is POSTed and I am redirected to the same JSP page the dropdown lists are empty because the necessary request attributes are not present.
I am quite the n00b when it comes to web apps, so an obvious & easy solution to this problem escapes me at the moment!
I am open to suggestions on how to restructure the control flow in the Servlet.
Some details about this app: standard Servlet + JSP, JSTL, running in Apache Tomcat 6.0.
Thanks.
.. and redirects to the same JSP page ..
You shouldn't fire a redirect here, but a forward. I.e. do not do
response.sendRedirect("page.jsp");
but rather do
request.getRequestDispatcher("page.jsp").forward(request, response);
This way the original request remains alive, including all the parameters and attributes. A redirect namely instructs the client to fire a brand new request, hereby garbaging the initial request.
In JSP you can access request parameters by ${param} in EL and you can access request attributes the same way with ${attributeKey} where attributeKey is the attribute key which you've used to set the object in the request scope in the servlet as follows:
request.setAttribute("attributeKey", someObject);
As to retaining HTML input values in a JSP, you just need to set the <input> element's value attribtue accordingly with the request parameter value:
<input name="foo" value="${param.foo}">
This prints the outcome of request.getParameter("foo") in template text. This has however a XSS risk, better is to escape any user-controlled input with help of JSTL's fn:escapeXml() as follows:
<%# taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
...
<input name="foo" value="${fn:escapeXml(param.foo)}">
Retaining the selected option in a dropdown is a bit different story. You basically need to set the selected attribute of the <option> element in question. Assuming that you're -as one usually would do- using JSTL's <c:forEach> tag to display a Map<String, String> or maybe a List<JavaBean> of option values, you can solve it as follows (assuming ${countries} is a Map<String, String> which you've placed as an attribute in the request, session or application scope):
<select name="country">
<c:forEach items="${countries}" var="country">
<option value="${country.key}" ${country.key == param.country ? 'selected' : ''}>${country.value}</option>
</c:forEach>
</select>
This prints the selected attribute when the currently iterated option key equals the submitted one in the request parameter map.