Background
Generate a report in various formats (e.g., PDF, delimited, HTML) using an ADF Task Flow.
Problem
HTTP headers are being sent twice: once by the framework and once by a bean.
Source Code
The source code includes:
Button Action
Managed Bean
Task Flow
Button Action
The button action:
<af:commandButton text="Report" id="submitReport" action="Execute" />
Managed Bean
The Managed Bean is fairly complex. The code to responseComplete is getting called, however it does not seem to be called sufficiently early to prevent the application framework from writing the HTTP headers.
HTTP Response Header Override
/**
* Sets the HTTP headers required to indicate to the browser that the
* report is to be downloaded (rather than displayed in the current
* window).
*/
protected void setDownloadHeaders() {
HttpServletResponse response = getServletResponse();
response.setHeader( "Content-Description", getContentDescription() );
response.setHeader( "Content-Disposition", "attachment, filename="
+ getFilename() );
response.setHeader( "Content-Type", getContentType() );
response.setHeader( "Content-Transfer-Encoding",
getContentTransferEncoding() );
}
Issue Response Complete
getFacesContext().responseComplete();
Bean Run and Configure
public void run() {
try {
Report report = getReport();
configure(report.getParameters());
report.run();
} catch (Exception e) {
e.printStackTrace();
}
}
private void configure(Parameters p) {
p.put(ReportImpl.SYSTEM_REPORT_PROTOCOL, "http");
p.put(ReportImpl.SYSTEM_REPORT_HOST, "localhost");
p.put(ReportImpl.SYSTEM_REPORT_PORT, "7002");
p.put(ReportImpl.SYSTEM_REPORT_PATH, "/reports/rwservlet");
p.put(Parameters.PARAM_REPORT_FORMAT, "pdf");
p.put("report_cmdkey", getReportName());
p.put("report_ORACLE_1", getReportDestinationType());
p.put("report_ORACLE_2", getReportDestinationFormat());
}
Task Flow
The Task Flow calls Execute, which refers to the bean's run() method:
entry -> main -> Execute -> ReportBeanRun
Where:
<method-call id="ReportBeanRun">
<description>Executes a report</description>
<display-name>Execute Report</display-name>
<method>#{reportBean.run}</method>
<outcome>
<fixed-outcome>success</fixed-outcome>
</outcome>
</method-call>
The bean is assigned to the request scope, with a few managed properties:
<control-flow-rule id="__3">
<from-activity-id>main</from-activity-id>
<control-flow-case id="ExecuteReport">
<from-outcome>Execute</from-outcome>
<to-activity-id>ReportBeanRun</to-activity-id>
</control-flow-case>
</control-flow-rule>
<managed-bean id="ReportBean">
<description>Executes a report</description>
<display-name>ReportBean</display-name>
<managed-bean-scope>request</managed-bean-scope>
...
</managed-bean>
The <fixed-outcome>success</fixed-outcome> strikes me as incorrect -- I don't want the method call to return to another task.
Restrictions
The report server receives requests from the web server exclusively. The report server URL cannot be used by browsers to download directly, for security reasons.
Error Messages
The error message that is generated:
Duplicate headers received from server
Error 349 (net::ERR_RESPONSE_HEADERS_MULTIPLE_CONTENT_DISPOSITION): Multiple distinct Content-Disposition headers received. This is disallowed to protect against HTTP response splitting attacks.
Nevertheless, the report is being generated. Preventing the framework from writing the HTTP headers would resolve this issue.
Question
How can you set the HTTP headers in ADF while using a Task Flow to generate a PDF by calling a managed bean?
Ideas
Some additional ideas:
Override the Page Lifecycle Phase Listener (ADFPhaseListener + PageLifecycle)
Develop a custom Servlet on the web server
Related Links
http://www.oracle.com/technetwork/middleware/bi-publisher/adf-bip-ucm-integration-179699.pdf
http://www.slideshare.net/lucbors/reports-no-notes#btnNext
http://www.techartifact.com/blogs/2012/03/calling-oracle-report-from-adf-applications.html?goback=%2Egde_4212375_member_102062735
http://docs.oracle.com/cd/E29049_01/web.1112/e16182/adf_lifecycle.htm#CIABEJFB
Thank you!
The problem was an incorrect implementation of RFC 2183:
response.setHeader( "Content-Disposition", "attachment; filename="
+ getFilename() );
The ; cannot be a ,.
Related
We having a specific problem in using Wicket 7.10, creating an Ajax-Response with multiple entries.
In our application, we are using onRequestHandlerResolved to do some initialization stuff and onRequestHandlerExecuted to save changes done on our data during requestHandlerExecutor.execute().
For this purpose, we have created an own AbstractRequestCycleListener which overwrites both methods and calls our specific code.
RequestCycle:
private void execute(IRequestHandler handler)
{
try
{
listeners.onRequestHandlerResolved(this, handler);
requestHandlerExecutor.execute(handler);
listeners.onRequestHandlerExecuted(this, handler);
}
catch (RuntimeException e)
{
}
}
Our problem is, that an Exception thrown in onRequestHandlerExecuted after requestHandlerExecutor.execute() has already created an ajax-response creates an invalid response:
Wicket.Ajax: Wicket.Ajax.Call.failure: Error while parsing response: Error: Invalid XML:
<?xml version="1.0" encoding="UTF-8"?>
<ajax-response>
<!-- Result of requestHandlerExecutor.execute() -->
</ajax-response>
<ajax-response>
<!—Redirect to specific Exception Page, result of onRequestHandlerExecuted -->
<redirect>
<![CDATA[./wicket/bookmarkable/our.package.ExceptionPage?locale=en]]>
</redirect>
</ajax-response>
To solve our problem, we tried to clear the existing Response during Exception in onRequestHandlerExecuted (RequestCycle.get().getResponse().reset()), but we are not able to clear the Response, created in requestHandlerExecutor.execute(), because Wicket uses HeaderBufferingWebResponse by default which did not allow to reset already created Response in encapsulated ServletWebResponse. Calling reset in HeaderBufferingWebResponse instead throws an IllegalStateException.
We think that the problem came from ServletWebResponse which simply adds multiple ajax-response entries to the HttpServletResponse which results in the mentioned, invalid XML.
ServletWebResponse:
#Override
public void sendRedirect(String url)
{
try
{
if (webRequest.isAjax())
{
/*
* usually the Ajax-Location header is enough and we do not need to the redirect url
* into the response, but sometimes the response is processed via an iframe (eg
* using multipart ajax handling) and the headers are not available because XHR is
* not used and that is the only way javascript has access to response headers.
*/
httpServletResponse.getWriter().write(
"<ajax-response><redirect><![CDATA[" + url + "]]></redirect></ajax-response>");
}
else { }
}
catch (IOException e) { }
}
How we could handle the problem when throwing an Exception in onRequestHandlerExecuted? And how is it possible, that code run after requestHandlerExecutor.execute(), redirects correctly to an Exception page?
How we can run specific code, after the request has been processed, is there maybe another way instead of overwriting onRequestHandlerExecuted?
For each Ajax request Wicket executes two request handlers:
ListenerInterfaceRequestHandler
AjaxRequestHandler
I assume your #onRequestHandlerExecuted is failing after the second one. This might be too late since the response is already generated and written.
You could check:
why does your listener fail after anything else has happened already?
what do you want your application to do when your listener fails?
can't the listener fail after the first handler already? why wait any longer?
I'm trying to integrate swagger in MYcommercewebservices.
I read post and done all steps listed on it, but still having this error.
https://localhost:9002/mycommercewebservices/v2/v2/api-docs working fine. https://localhost:9002/mycommercewebservices/v2/swagger-ui.html - return UnknownResourceError.
Furthermore - if I navigate to https://localhost:9002/mycommercewebservices/swagger-ui.html (without 'v2') it'll show me this message (javascript alert):
Unable to infer base URL. This is common when using dynamic servlet
registration or when the API is behind an API Gateway. The base URL is
the root of where all the swagger resources are served. For e.g. if
the API is available at http://example.org/api/v2/api-docs then the
base URL is http://example.org/api/. Please enter the location
manually:
I found this controller, and probably part of the problem was in it because it was throwing an exception when I navigated to https://localhost:9002/mycommercewebservices/v2/swagger-ui.html
#Controller
public class DefaultController
{
#RequestMapping
public void defaultRequest(final HttpServletRequest request)
{
throw new UnknownResourceException("There is no resource for path " + YSanitizer.sanitize(request.getRequestURI()));
}
}
Now I disabled controller, but still having the same exception, but now it's in json format instead of .xml.
Thank you!
The main problem was in DefaultController (in MYcommercewebservices)
#Controller
public class DefaultController
{
#RequestMapping
public void defaultRequest(final HttpServletRequest request)
{
throw new UnknownResourceException("There is no resource for path " + YSanitizer.sanitize(request.getRequestURI()));
}
}
It was catching my request and throwing the exception.
When I disabled this controller, I continued to receive an exception, but now it was in json format(before it was in xml).
Than I added this to springmvc-v2-servlet.xml
<mvc:default-servlet-handler/>
<mvc:resources mapping="swagger-ui.html" location="classpath:/META-INF/resources/"/>
<mvc:resources mapping="/webjars/**" location="classpath:/META-INF/resources/webjars/"/>
Now UI works fine!
Also there were another manipulation before all this, but you can find them in hybris experts(quite big post).
I'm developing a dart application which will consume a REST service I'm building. I started writing out the dart code to perform an ajax request to my login endpoint. However, even when my dart ajax request should fail, it claims to succeed.
I don't have any services up and running (and even if I did it would be using the wrong domain / port right now), but this code gives a 200 OK HttpResponse every time:
class PlayerController {
const PlayerController();
static const String LOGIN_URL = "login";
void login(String username, String password) {
Map<String, String> headers = {"Content-Type": "application/x-www-form-urlencoded"};
String body = "j_username=$username&j_password=$password&submit=Login";
HttpRequest.request(LOGIN_URL, method: "POST", requestHeaders: headers, sendData: body)
.then((request) => processLogin(request, username))
.catchError((e) => processLoginError(e));
}
void processLogin(var whatIsThis, String username) {
query("#loginButton").text = "Logout";
//TODO get the player then set them
}
void processLoginError(var e) {
print("total failure to login because of $e");
}
}
It always hits the processLogin method, and never hits the processLoginError method. Does anyone have any idea why this would be? Should I be performing this ajax request in a different way? (If you couldn't guess, it will be signing into spring security).
I read somewhere that file system requests always succeed. Is Dart somehow making this a file system request rather than a web request?
This is because the request actually completes successfully.
Your request to "login" will actually call http://127.0.0.1:6521/[Path_to_your_Dart_file]/login
The server started by Dart when running in Dartium (127.0.0.1:6521) seems to answer to every POST request with HTTP 200 and an empty response body.
If you change the method from POST to GET, it will fail as expected.
As for why the server does this - I don't really know. This would have to be answered by the Dart team.
I have an action that is called using requests with application/jsonin the Content-type header. These requests will automatically create a JsonValueProvider that tries to deserialize the request's content. When the json is malformed, the value provider will throw an exception leading to the application's error page.
To reproduce this behavior, simply POST invalid json data to an action sending application/json as the Content-type header. This will trigger the exception.
[Edit]
Not much code is needed. Simply create an empty controller method and use a tool like Firefox "Poster" to send an invalid request to the action.
public class HomeController
{
public ActionResult Index()
{
return this.Json(true);
}
}
Then use Poster:
Set Content-type to application/json
Set Request content to {"This is invalid JSON:,}
Send the request
The result will be the full-blown standard ASP.NET HTML error page (either generic or custom, depending on your application).
[/Edit]
Since my action is called by embedded devices, I would like to send short responses, instead of the HTML error page. I would like to be able to create a response with status code 500, Content-type: text/plain, and the exception's message as it's content.
I have already tried a custom model binder and a custom error handler attribute but neither are called since the exception occurs earlier on in the processing pipeline. Is there a way to handle this error?
As a workaround, I have currently disabled the JsonValueProvider for the whole application and load the values from the request body myself. If there is a way to disable the JsonValueProvider on a per action basis, this would also help.
Thanks in advance for any pointers!
You could subscribe to the Application_Error event in your Global.asax and handle the exception as you want:
protected void Application_Error(object sender, EventArgs e)
{
var exception = Server.GetLastError();
Response.TrySkipIisCustomErrors = true;
Response.Clear();
Server.ClearError();
Response.StatusCode = 500;
Response.ContentType = "text/plain";
Response.Write("An error occured while processing your request. Details: " + exception.Message);
}
I have a JSF Phase Listerner that checks to see if the user is logged in, and if not, redirects them to the login page. This is working fine for non-ajax requests. However, if the user is on a page, in my case, one that has a primefaces data table, and clicks on a button that invokes an ajax request -- but their session has timed out -- the code gets executed that issues the redirect (using ExternalContext#redirect), however the user is not navigated to the login page.
Any idea why this is not working?
Here is my phase listener:
private static final String IS_LOGGED_IN_INDICATOR = "loggedIn";
private static final String LOGIN_PAGE = "/login.jsp";
public PhaseId getPhaseId() {
return PhaseId.RESTORE_VIEW;
}
public void beforePhase(PhaseEvent event) {
ExternalContext ec = FacesContext.getCurrentInstance().getExternalContext();
HttpSession session = (HttpSession)ec.getSession(false);
if (session==null || session.getAttribute(IS_LOGGED_IN_INDICATOR) == null) {
try {
ec.redirect(LOGIN_PAGE);
}
catch(IOException e) {
// log exception...
}
}
}
public void afterPhase(PhaseEvent event) {
// no-op
}
}
It failed because the ajax context is trying to obtain the render kit from the view root, while there is no view root at all. It has not been restored at that point yet. This resulted in a NullPointerException in PartialViewContext#createPartialResponseWriter(). This exception is in turn not been thrown, but instead been put in an ajax exception queue which is supposed to be handled by a custom ExceptionHandler. You apparently don't have any one. This exception is visible if you create/use such one like the FullAjaxExceptionHandler (see also this blog for more detail).
To fix the particular problem, do the job in afterPhase() instead. The view root is then fully restored and the ajax context can obtain the render kit from it in order to write a specialized XML response which instructs the JSF ajax engine in JavaScript to change the window location. Without ajax, a render kit was not necessary as a redirect is basically just a matter of setting a response header.
Whether the particular NullPointerException is in turn a bug in Mojarra or not is a different question which can better be posted in flavor of an issue report at their own issue tracker.
this is because you have to send a special response in XML for Ajax request in order to do redirect (check this answer) , I have implemented this in a Filter like this..
// Check if it's an Ajax Request
if ("partial/ajax".equals(((HttpServletRequest) request).getHeader("Faces-Request"))) {
//redirect
response.setContentType("text/xml");
response.getWriter()
.append("<?xml version= \"1.0\" encoding=\"UTF-8\"?>")
.printf("<partial-response><redirect url=\"%s\"></redirect></partial-response>",url);
you should port this to your Phase Listener.