I'm creating a custom framework (something like portal) for numerous JSF 1.x and 2.x applications. For that purpose I created a servlet filter that "enrich" application HTML with framework menu, breadcrumb, logout, etc. In that filter I read app's HTML, modify it and write it to an output stream. So far everything worked great but now I'm having problem with creating a custom error page.
I tried to read a response status code and based on that code, I'm creating output HTML:
public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
HttpServletRequest req = (HttpServletRequest) req;
HttpServletResponse res = (HttpServletResponse) resp;
StringServletResponseWrapper responseWrapper = new StringServletResponseWrapper(res);
// Invoke resource, accumulating output in the wrapper.
chain.doFilter(req, responseWrapper);
String contentType = res.getContentType();
byte[] data;
if (contentType.contains("text/html")) {
String html = null;
int statusCode = res.getStatus();
LOG.debug("status: {}, committed: {}", statusCode, res.isCommitted());
if (statusCode != 200) {
html = "<!DOCTYPE html>\r\n" +
"<html xmlns=\"http://www.w3.org/1999/xhtml\">\r\n" +
"<head>\r\n" +
"<script type=\"text/javascript\" src=\"/path/to/jquery/jquery-1.11.1.min.js\"></script>\r\n" +
"<title>Error</title>\r\n" +
"</head>\r\n" +
"<body>\r\n" +
"<h1>Error</h1>\r\n" +
"</body>\r\n" +
"</html>";
Collection<String> headerNames = res.getHeaderNames();
Map<String, String> headerMap = new HashMap<String, String>();
for (String header : headerNames) {
headerMap.put(header, res.getHeader(header));
}
res.reset();
for (Map.Entry<String,String> entry : headerMap.entrySet()) {
res.setHeader(entry.getKey(), entry.getValue());
}
res.setStatus(statusCode);
response.setContentType("text/html");
} else {
html = responseWrapper.getCaptureAsString();
}
if (ObjectUtils.isNotEmpty(html)) {
// do some modification
String modifiedResponse = doModification(html);
data = modifiedResponse.getBytes("UTF-8");
response.setContentLength(data.length);
response.getOutputStream().write(data); // this line causes error
}
} else {
data = responseWrapper.getCaptureAsBytes();
response.setContentLength(data.length);
response.getOutputStream().write(data);
}
}
This code works without any problem if status code equals 200 (else clause), but when it's not equal to 200 (I triggered 404 error), the following error occures:
com.ibm.ws.webcontainer.webapp.WebApp logServletError SRVE0293E: [Servlet Error]-[Faces Servlet]: java.lang.IllegalStateException: SRVE0209E: Writer already obtained
I don't really understand why does this error appear. The only difference between two cases is HTML content which is valid in both cases. Any help?
Using Websphere Application Server 8.5.5.18.
EDIT: I've tried to call reset() and then set headers and status code again, but that reset() call causes an IllegalStateException - as stated in javadoc, apparently response has already been committed. As far as I understand, flush() method of ServletOutputStream could cause response to be committed, but I'm not calling it anywhere. I've also added some log to see if response really is committed. In both cases (status 200 and 404) response.isCommitted() returns true. Does that mean that response is committed before doFilter is called?
Option 1 - downgrade JAX-RS to 1.1
Once JAX-RS version is changed back to 1.1 the errors in SystemOut.log will not be shown.
Do the following steps:
Change the JAX-RS version to 1.1 using WAS 9 Admin console. See the detailed instructions at
https://www.ibm.com/support/knowledgecenter/SSEQTP_9.0.0/com.ibm.websphere.base.doc/ae/twbs_jaxrs_coexist_adminconsole.html
Option 2 - move chain.doFilter to the end of your doFilter method
chain.doFilter(req, resp);
}
Option 3 - Remove other usages of PrintWriter or OuputStream
Review application to determine if both PrintWriter and OuputStream were obtained. Modify the failing servlet/JSP to only obtain one or the other.
Related
I am trying to compress my response when the request header contains gzip in Accept-Encoding. However, adding following to app.properties only works when controller method is returning an object.
server.compression.enabled=true
server.compression.min-response-size=1
server.compression.mime-types=application/json,application/xml,text/html,text/xml,text/plain,application/javascript,text/css
I am writing directly to response stream. So, above compression properties don't work.
My method looks like this:
#GetMapping(path = "/something", produces = MediaType.TEXT_PLAIN_VALUE)
public void getSomething(#RequestParam(name = "paramA") String paramA,
HttpServletRequest request,
HttpServletResponse response) throws IOException {
PrintWriter writer = null;
if (request.getHeader("Accept-Encoding").contains("gzip")) {
writer = new PrintWriter(new OutputStreamWriter(new GZIPOutputStream(response.getOutputStream())));
response.addHeader(HttpHeaders.CONTENT_ENCODING, "gzip");
} else {
writer = response.getWriter();
}
final PrintWriter fwriter = writer;
someObjectInstance.getSomething(paramA).forEach(x -> {
fwriter.write(x.toString());
});
fwriter.flush();
}
When I curl the above method, I get an empty file.
I did try to use the GzipFilter by referring to the following link.
http://www.javablog.fr/javaweb-gzip-compression-protocol-http-filter-gzipresponsewrapper-gzipresponsewrapper.html, which works by the way.
However, the filter requires alot of boilerplate code. Is there a way I can make changes in controller method and solve the problem as in the link mentioned above.
Just realised I was not closing the writer.
After adding fwriter.close(); in the end, the problem was solved.
I have implemented a #OneWay JAX-RS service with Apache CXF ( a dropwizard application ). When called with invalid structure, causing an unmarshalling error in DocLiteralInInterceptor, http status code 200 is returned to client. To make the calling process recognize the fault, I need to return status 400 or 500, along with the error text from Unmarshalling Error.
I recognized that, after the error, the "in" interceptor chain is unwound ( interceptors handleFault-methods are called in reverse order ), so I installed an interceptor at the start of the "in"-chain ( last on unwinding ) with
public CustomSOAPInterceptor(String chainname) {
super(Phase.RECEIVE);
getBefore().add(PolicyInInterceptor.class.getName());
this.chainname=chainname;
}
Within my handleFault-Method I can seperate the fault message and recognize the unmarshall error. But I am not succeeding in setting the response.
I tried
Fault f = (Fault) e;
f.setStatusCode(Response.Status.BAD_REQUEST.getStatusCode());
and
Response response = Response
.status(Response.Status.BAD_REQUEST)
.entity(Response.Status.BAD_REQUEST.getStatusCode() + " " + f.getLocalizedMessage())
.build();
soapMessage.getExchange().put(Response.class, response);
and
message.put(Message.RESPONSE_CODE, Response.Status.BAD_REQUEST.getStatusCode());
Where is the response set and how can I overwrite it ?
Tx for any advice.
I know, its kind of late, but for those who are looking for a solution:
In my application, the following works:
public void handleFault(SoapMessage soapMessage) {
/* some code to test for specific error deleted */
Exchange exchange = soapMessage.getExchange();
Message outMessage = exchange.getOutMessage();
if (outMessage == null) {
Endpoint endpoint = exchange.get(Endpoint.class);
outMessage = endpoint.getBinding().createMessage();
exchange.setOutMessage(outMessage);
}
try {
EndpointReferenceType target = exchange.get(EndpointReferenceType.class);
Conduit conduit = exchange.getDestination().getBackChannel(soapMessage);
exchange.setConduit(conduit);
conduit.prepare(outMessage);
} catch (IOException ex) {
LOG.error(ex.getMessage(), ex);
}
Object resp = outMessage.get("HTTP.RESPONSE");
if (resp != null && resp instanceof HttpServletResponse) {
HttpServletResponse response = (HttpServletResponse) resp;
response.setStatus(Response.Status.BAD_REQUEST.getStatusCode());
}
soapMessage.getInterceptorChain().abort();
}
My RSS servlet uses try-with-resource for the OutputStream out of the HttpServletResponse and the writer for it. In some cases SomeException is thrown whilst generating the RSS document, in which case I need to return an HTTP status 500 to the client:
try (ServletOutputStream out = response.getOutputStream();
OutputStreamWriter writer = new OutputStreamWriter(out, "utf-8")) {
response.setContentType("text/xml");
// Generate RSS here
} catch (SomeException e) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e.getMessage());
return;
}
However, by the time response.sendError() is called, the $out$ has already been closed and I get said IllegalStateException saying that the response has already been committed (closing the stream seems to commit the response automatically ).
If I move the initialization of out and writer outside of the try-block and close them in a finally-block (the pre-Java7 way), the error code gets sent correctly.
I was wondering whether there's a way to keep using try-with-resource and still be able to return error codes in case of an exception.
Thanks!
You don't need to close resources which you didn't create yourself. The container created the underlying OutputStream all by itself and is therefore also all by itself responsible for properly closing it. You should visualise it that the container has already put a try-with-resources around the servlet's doXxx() method. See also Should I close the servlet outputstream?
Differently put, the whole try-with-resources on OutputStream inside doXxx() is unnecessary.
Just do:
try {
// Generate RSS here
OutputStreamWriter writer = new OutputStreamWriter(response.getOutputStream(), "UTF-8")) {
response.setContentType("text/xml");
// Write RSS here.
} catch (SomeException e) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e.getMessage());
}
Unrelated to the concrete problem, if you rethrow any checked exception as ServletException, then the container will also all by itself take care of the proper response code and message.
try {
// ...
} catch (SomeException e) {
throw new ServletException(e);
}
I'm using Jetty 9's implementation of HttpServletRequest#getPart(name), and it appears to eagerly processes the entire request (or at least the Part in question) before continuing, even though the resulting Part exposes a getInputStream() method.
Is there a way for getPart to return immediately, and leave request streaming to the resulting Part's InputStream?
For reference, here's the relevant snippet from my Servlet implementation:
override def doPost(req: HttpServletRequest, res: HttpServletResponse) {
println("ABOUT TO GET PART") // this happens immediately
val file = req.getPart("file")
println("GOT PART") // it takes a long time to get here if the upload is large
It's wicked tedious, but this can be done using MultipartStream from commons-fileupload:
try {
MultipartStream multipartStream = new MultipartStream(input, boundary);
boolean nextPart = multipartStream.skipPreamble();
OutputStream output;
while(nextPart) {
String header = multipartStream.readHeaders();
// process headers
// create some output stream
multipartStream.readBodyData(output);
nextPart = multipartStream.readBoundary();
}
} catch(MultipartStream.MalformedStreamException e) {
// the stream failed to follow required syntax
} catch(IOException e) {
// a read or write error occurred
}
This requires the use of the InputStream from HttpServletRequest#getInputStream(), and the boundary delimiter encoded in the HTTP request's content type:
Content-Type: multipart/form-data; boundary=------------------------bd019839518ca918
I am trying to implement restful protocol on jetty server. I have runnable server and i can access it from my rest client. My server side project is a maven project. I have a problem about the character encoding.When i check response, before send it from controller, there is no encoding problem. But after i return response to client, i see broken data. Response header is UTF-8. Also i have a listener for this problem and i am setting to request and response to UTF-8. I guess problem happens when i try to write my response data to response.
#GET
#Path("/")
#Produces({"application/xml;charset=UTF-8","application/json;charset=UTF-8"})
public String getPersons(#Context HttpServletRequest request, #Context HttpServletResponse response) {
List<Person> persons = personService.getPersons(testUserId, collectionOption, null);
if (persons == null) {
persons = new ArrayList<Person>();
}
String result = JsonUtil.listToJson(persons);
//result doesnt has any encoding problem at this line
response.setContentType("application/json");
response.setContentLength(result.length());
response.setCharacterEncoding("utf-8");
//i guess problem happen after this line
return result;
}
Is there any jetty configuration or resteasy configuration for it? Or is there any way to solve this problem? Thanks for your helps.
Which resteasy version are you using? There is a known issue (RESTEASY-467) with Strings in 2.0.1 an prior.
These are your options:
1) force the encoding returning byte[]
public byte[] getPersons
and then
return result.getBytes("UTF8");
2) return List (or create a PersonListing if you need it)
public List<Person> getPersons
and let resteasy handle the json transformation.
3) return a StreamingOutput
NOTE: with this option the "Content-Length" header will be unknown.
return new StreamingOutput()
{
public void write(OutputStream outputStream) throws IOException, WebApplicationException
{
PrintStream writer = new PrintStream(outputStream, true, "UTF-8");
writer.println(result);
}
};
4) upgrade to 2.2-beta-1 or newer version.