Response setHeader in scriptless manner?

isn't there a way to get something like
<%
response.setHeader("Pragma","no-cache");
response.setHeader("Cache-Control","no-cache");
response.setHeader("Expires","0");
%>
in a scriptless manner?

thank you, as a lot can be done with plain JSP, EL, JSTL I hoped there was a way to set headers too. Anyway, meanwhile I implemented a small EL function to do the job:
call in JSP:
<c:set var="id" value="${comundus:disableCaching(pageContext.response)}"/>
(it is not really necessary to set a variable though)
TLD entry:
<function>
<name>disableCaching</name>
<function-class>com.comundus.util.HTTPUtil</function-class>
<function-signature>
void disableCaching(javax.servlet.http.HttpServletResponse)
</function-signature>
</function>
Java method:
public static void disableCaching(HttpServletResponse res) {
res.setHeader("Pragma","no-cache");
res.setHeader("Cache-Control","no-cache");
res.setHeader("Expires","0");
}

Similar Messages

Response.setHeader() does not work

Hi,
          We have not been able to set any header parameters using response.setHeader() method. Has anybody else seen this problem ? I read a posting in this newsgroup ( Subject: RE: Re: setHeader with Response.sendRedirect ) which mentioned a change request # CR073102 filed for this with BEA. Any update or workaround for this issue ?
          Thanks in advance.
          Amar


I'm assuming that you are attempting to bypass the sign-on prompt from the other site. What you will have to do is access the other site from within your servlet and foward the content to the user. In other words, you would be setting your servlet(s) up as a proxy. This can become rather complex as you may run into the need to handle cookies and such from your servlet. Another alternative, if you can modify the remote site, is to set up the other site to accept some sort of keyword or password that your servlet can include in the URL string which would bypass the initial signon.

Doubt in response.setHeader();

If I tried to set the header using
response.setHeader(�My Header Name�,�My Header Value�);
But while retrieving using getHeader(�My Header Name�); it is giving me null�..
I am setting and getting the header in the same serlvet�.
What might be the problem?
Thanks In Advance.
Bennet Xavier. X
Edited by: Bennet on May 12, 2008 3:05 AM

i added my own header in the servlet using response Object and trying to get the header back in the same servlet using request Object...
i dont know whether its correct or not.It isn't. A response is not a request. Client sends a request, server sends a response. It is astounding that you would think that setting a property of some object would enable you to get that property from a different, unrelated object.
if not, Tell me how to set the header and get back header values.When you set a header on an object, ask that object for the header. Look at the following code; it's roughly equivalent to what you seem to be expecting:public class Foo {
    public static void main(String[] args) {
        A a = new A();          // 1.
        B b = new B();          // 2.
        a.set(42);              // 3.
        int x = b.get();        // 4.
        assert x != 42;         // 5.
        assert 42 == a.get();   // 6.
class A {
    int i;
    void set(int i) {
        this.i = i;
    int get() {
        return i;
class B {
    int n;
    void set(int n) {
        this.n = n;
    int get() {
        return n;
}Have a good look at line 4. Following the same logic you're applying to the request/response, you would expect x to have the value 42. If this doesn't immediately strike you as nonsensical, step away from the Java EE and brush up on the fundamentals of OOP. That's not meant to be an insult; just think carefully about what you're trying to do.
~

Adding custome header : response.setHeader()

HI
I have an application where in authorization is done from a different server. When we hit our app's URL proxy redirects to that othorizing server and that server adds a header named sn_userdn in the header and we read that header and accordingly we do the further processing based on that.
But now I need to bypass this thing. I need to develop a login page which gets the user information and sets same header this is because we are going to not use the third party authorization any more.
I am useing response.addHeader("sn_userdn","binoyb9");but while trying to read it as we were doing it previously it gives null.
can you tell me why?
How do i set custom headers in jsp?

response.addHeader() will add a header that goes back to the response, usually to the browser. If something isn't intercepting that after that, it's not going to be there. I think it seems you are adding something to the wrong place. Perhaps a servlet filter could be used to add the header before the servlet/jsp page gets it.

Re: How do I pass the session when I use response.setHeader

Got it..
I was using setHeader("Location","second.jsp") instead of setHeader("location","second.jsp").
Headers are case sensititve for SunOne Appserver.
-Srinivas

If you are using the Standalone version, then first of all make sure to UNCHECK (BIP10g 10.1.3.4.1)
"AUTO RUN" (it is under General Settings when you select your Report Definition)
Next, you should define the parameters in the corresponding parameter Section.
Its simplest form is of "Text" type so you will have to enter values at runtime.
Then these parameters can be used in your query as bind variables.
When you run the report it will prompt for parameter values. Enter these values
and you would get a sample of your XML data.
This should work and you should not find any issues.
regards
Jorge

Error while processing a response

Hi, i have the next error while my class is processing the response. The
error is:
java.lang.NoSuchMethodError at
com.bea.portal.appflow.servlets.internal.PortalWebflowServlet.doGet(PortalWe
bflowServlet.java:214) at
javax.servlet.http.HttpServlet.service(HttpServlet.java:740) at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at ...
My class only retrieve a param by request and send to response a image
archive from a DB. The code is:
response.setContentType(img.getMimetype().trim());
response.setHeader("Content-disposition","attachment; filename=\"" +
img.getNombre().trim()+"\"");
response.setHeader("Cache-Control", "no-cache");
response.setContentLength(img.getTamanoBytes());
try {
ServletOutputStream servletoutputstream =
response.getOutputStream();
servletoutputstream.write(buffer);
servletoutputstream.flush();
servletoutputstream.close();
catch (IOException ex3) {
throw new ProcessingException(ex3.toString());
The "img" object contains my image properties and the "buffer" variable
contains the byte array with the image.
Has anybody idea whats happening??
Thanks in advance.

Hi Sambo44,
Thanks for your posting!
I am not totally understanding your meaning. How did you get this error?Did you want to login on Azure form your VS? From your error message, I am not sure you can login on Azure portal using your account. Please make sure your account is right.
Or did you try to use ACS or WIF in your project for authorization? If it is , I suggest you can post this issue on Azure AD forum for more details.
Any question about this issue, please feel free to let me know.
Regards,
Will
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How to Modify Data in a Servlet Response

Hi..
I have a servlet that upon receving an http request from client sends some data to the client browser, but i want to modify the data that is being sent to the client and resend it somehow (like its a kind of bypassing...without sending the original data..i want to modify the data and send the response ON THE FLY.
Any ideas of suggestions how to do it, if some one of you has already done it then pls do send some code snippet.
Thanx in advance
mark.

Aha... now the truth comes out. You asked how to do it, but your secret question was that you were already doing it and you were having some problems. It's generally just better to come out and ask the question, even though it may be embarrassing that what you did isn't working.
To me, what you did sounds like a perfectly good method, except that writing the data to a temp file is going to run you into problems as soon as you get two requests at about the same time. I would do that in memory instead (write to a ByteArrayOutputStream, get the resulting array of bytes, modify it, and write the end result out to the servet response's output stream).
The problem you describe, though, is probably caused because the browsers are caching requests to your servlet. Do you have something like this code in your servlet that tells the browsers not to cache it?response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");

File get currupt if downloaded by response.getOutputStream();

Hi,
I am trying to download file (of any type pdf/rar/any etc...) using following code,
but SOME TIME downloaded file is currupted.
            File file = new File(filePath);
            if (file.exists()) {
                if(isDebugEnabled)
                    log.debug("File Found");
            String quotes = "\"";
            attachmentName = quotes.concat(attachmentName).concat(quotes);
            response.setContentType("application/unknown");
            response.setHeader("Pragma", "public");
            response.setHeader("Cache-Control", "max-age=0");
            response.addHeader("Content-Disposition", "attachment; filename="
                    + attachmentName);
            fileInputStream = new FileInputStream(file);
            OutputStream tempStream = response.getOutputStream();
            if (tempStream instanceof FileOutputStream && tempStream != null) {
                destination = ((FileOutputStream) tempStream).getChannel();
                source = new FileInputStream(file).getChannel();
                destination.transferFrom(source, 0, source.size());
            } else {
                outputStream = tempStream;
            int bytesRead;
            while ((bytesRead = fileInputStream.read()) != -1){
                outputStream.write(bytesRead);
{code}
but when I use
{code}
       File f1=new File("MyFile");
       OutputStream outputStream=new FileOutputStream(f1);
{code}
insted of
{code}OutputStream tempStream = response.getOutputStream(); {code}
It works, & download file by name "MyFile" in bin of tomcat folder.
but not work with response object.

I did that in finally, here is the whole function code,
public static boolean downloadAttachment(HttpServletResponse response,
               String filePath, String attachmentName) throws Exception {
          boolean fileDownloadedStatus = false;
          FileInputStream fileInputStream = null;
          OutputStream outputStream = null;
          FileChannel source = null;
          FileChannel destination = null;
          try {
               File file = new File(filePath);
               if (file.exists()) {
                    if(isDebugEnabled)
                         log.debug("File Found");
               String quotes = "\"";
               attachmentName = quotes.concat(attachmentName).concat(quotes);
               response.setContentType("application/unknown");
               response.setHeader("Pragma", "public");
               response.setHeader("Cache-Control", "max-age=0");
               response.addHeader("Content-Disposition", "attachment; filename="
                         + attachmentName);
               fileInputStream = new FileInputStream(file);
               OutputStream tempStream = response.getOutputStream();
               if (tempStream instanceof FileOutputStream && tempStream != null) {
                    destination = ((FileOutputStream) tempStream).getChannel();
                    source = new FileInputStream(file).getChannel();
                    destination.transferFrom(source, 0, source.size());
               } else {
                    outputStream = tempStream;
               int bytesRead;
               while ((bytesRead = fileInputStream.read()) != -1){
                    outputStream.write(bytesRead);
               fileDownloadedStatus = true;
          } catch (FileNotFoundException fileNotFoundException) {
               log.error("FileNotFoundException");
               throw fileNotFoundException;
          } catch (Exception exception) {
               log.error("Exception");
               throw exception;
          } finally {
               if (source != null)
                    source.close();
               if (destination != null)
                    destination.close();
               if (fileInputStream != null)
                    fileInputStream.close();
               if (outputStream != null)
                    outputStream.close();
          return fileDownloadedStatus;
     }     {code}
I also checked with outputstream.flush, but not working.

Setting File Name in response

Hi,
On server side I read the (Pdf) file and then stream the file content thru response object so that this pdf file opens in browser using Adobe reader. This works just fine.
And right now, if user wants to save this file in browser, complete jsp url appears as file name in save as dialog box.
For eg.:
If my jsp has stream the pdf file from this url
http://www.xy.com/jsp/displayFileJsp?f=xyz.pdf
then
when user tries to save this file, browser save as dialog displays file name as "http://www.xy.com/jsp/displayFileJsp?f=xyz.pdf"
But I want user should download that file name with specific file name like xyz.pdf.
I tried to set the content type
response.setHeader("Content-Disposition", " filename=xyz.pdf" );
But it didn't work.
any suggestions ?
rk

i have created a zip file and i have to make it downloadable i.e. pop-up box should be invoked. my code is
try {
          outFilename = "D:\\Product.zip";
          ZipOutputStream out = new ZipOutputStream(new FileOutputStream(outFilename));
          for (int i=0; i<filenames.length; i++) {
          FileInputStream in = new FileInputStream(filenames);
          out.putNextEntry(new ZipEntry(filenames[i]));
          int len;
          while ((len = in.read(buf)) > 0) {
          out.write(buf, 0, len);
          out.closeEntry();
          in.close();
          out.close();
          catch (IOException e)
               e.printStackTrace();
          String d1file = outFilename;
          File f1 = new File (d1file);
               response.setContentType ("text/plain");
               response.setHeader("Content-Disposition", "attachment;filename=\"" + d1file + "\"");
          try {
          InputStream in = new FileInputStream(f1);
          ServletOutputStream outs = response.getOutputStream();
          int bit = 256;
               while ((bit) >= 0)
                    bit = in.read();
                    outs.write(bit);
               outs.flush();
               outs.close();
               in.close();
          catch (IOException ioe)
               ioe.printStackTrace(System.out);
it is creating zip file and placing it at D:\\ . I want to invoke download "Save As" pop up box, which is not appearing here! what should I do?

Down excel file in managed bean, no response?

Hi,
I used JDev 11.1.2
I want to download an excel file by click one button, and I want to implement this function in the managed bean, but after I click the button, no file download, and just refresh the page.
JSP snippet code:
<af:commandToolbarButton text="View Report" id="ctb1" actionListener="#{reportBean.viewReport}">
Method of managed bean(not show exception process ):
public void viewReport(ActionEvent actionEvent) {
// some validation here
FacesContext facesContext = FacesContext.getCurrentInstance();
ExternalContext externalContext = facesContext.getExternalContext();
HttpServletResponse response = (HttpServletResponse)externalContext.getResponse();
BufferedInputStream input = null;
BufferedOutputStream output = null;
String filePath = "c:/a.xls";
File file = new File(filePath);
try {
input = new BufferedInputStream(new FileInputStream(file), 1024);
response.reset();
response.setHeader("Content-Disposition", "attachment; filename=\"" + filePath + "\"");
response.setContentType("application/ms-excel");
output = new BufferedOutputStream(response.getOutputStream(), 10240);
byte[] buffer = new byte[10240];
int length;
while ((length = input.read(buffer)) > 0) {
output.write(buffer, 0, length);
output.flush();
}catch(Exception e){
} finally {
//close output and input
facesContext.responseComplete();
BTW: I can implement the download function by using fileDownloadActionListener, but our requirement needs to validate some information before download(such as status validation, file existence), and I add those validation to fileDownloadActionListener method, but seems no useful.
Any advices?
Thanks,
zeroxin

Timo,
I used the solution mentioned in your blog, and it really can enter into fileDownloadActionListener method, but still not display download file dialog, just seems no useful, I test it using Firefox4 and IE9, the same result.
JSP snippet code:
<af:commandToolbarButton text="View Report" id="ctb1"
actionListener="#{reportBean.viewReport}"/>
<af:commandToolbarButton text="Export..." id="ctb2" visible="false"
binding="#{reportBean.exportReportButton}">
<af:fileDownloadActionListener contentType="application/vnd.ms-excel" filename="Report.xls" method="#{reportBean.reportFileDownload}" />
</af:commandToolbarButton>
Bean method(Snippet code)
private RichCommandToolbarButton exportReportButton;
public void viewReport(ActionEvent actionEvent) {
// validate code here
ActionEvent ae = new ActionEvent(exportReportButton);
ae.queue();
public void reportFileDownload(FacesContext facesContext, java.io.OutputStream outputStream) throws Exception {
DCIteratorBinding dciter = (DCIteratorBinding)getBindings().get("SReportView1Iterator");
Object outputLoc = dciter.getCurrentRow().getAttribute("OutputLoc");
BufferedInputStream input = null;
try {
input = new BufferedInputStream(new FileInputStream((String)outputLoc), 1024);
byte[] buf = new byte[1024];
int count=0;
while ((count = input.read(buf)) >= 0) {
outputStream.write(buf, 0, count);
input.close();
outputStream.flush();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
thanks,
zeroxin

Writing different Content Types to Response

I am writing the part of an application that will display documents that users have stored on the system. The types we allow or .tiff, , .PDF, Word, and Excel.
I am sending the contents of the file to the response with this code:
PrintWriter out = response.getWriter();
File file;
ServletContext sc = getServletContext();
String mimetype;
file = new File(pathToFile);
mimetype = sc.getMimeType(pathToFile);
response.setContentType(mimetype);
// Read in the file and send chars to response
FileReader fReader = new FileReader(file);
char[] chars = new char[500];
while((fReader.read(chars)) != -1) {
out.write(chars);
fReader.close();
out.flush();
out.close();The mime types I am using are
application/msword
application/vnd.ms-excel
application/pdf
image/tiff
Word works great. Excel sort of works. IE displays an error that data may be lost, but then displays the worksheet.
PDF half works. The table of contents displays in the left frame, but the right content frame is blank. And tiff only shows a distorted version of the image.
And it doesn't work in Firefox at all. I just get a blank frame regardless of the file type.
My question is, am I doing this correctly? Am I reading in the file and writing it back to the response the correct way? PDF and TIFF are working partially but not 100%. I feel like I am missing something.
Thanks,
Karl

Thanks a lot. It works perfectly now........in IE.
In Firefox PDF and images work ok, but for Word and Excel I get endless "Open With.." dialogs. Is this a plugin issue? I added the following line to my servlet with no change in result:
response.setHeader("Content-Disposition","inline");
Thanks,
Karl

SetHeader problem when user downloads a file from a server

Hi everyone,
I have a question about the way to let a user download a file. A created a jsp that handles the download. This is the code:
<%@ page import="java.io.*" %><%
    response.setHeader("Content-Disposition", "attachment; filename=" + session.getAttribute("executedCommand").toString());
    response.setContentType("text/csv");
    int iRead;
    FileInputStream stream = null;
    try {
        File f = new File(session.getAttribute("executedCommand").toString());
        stream = new FileInputStream(f);
        while ((iRead = stream.read()) != -1) {
            out.write(iRead);
        out.flush();
    }finally {
        if (stream != null) {
            stream.close();
%>When I run this, I get a download window, so that the right file can be downloaded, but I would like the application to show me the name of that file in the download window and in my save dialog, and that's something I haven't managed to do yet, because I always get the name of the servlet (that redirects to the jsp page). So the problem is, the right file is downloaded but it's name is never shown in the download window. How can I resolve that?
Thanks for your help!
E_J

I forgot to say that my session variable contains the absolute path of the file the user can download. Maybe using session variables is not the best solution in this case, but it should have to work, shouldn't it?
Still waiting for some help. I really appreciate it...
E_J

Bug setting Content-Disposition of response with the July 20th build of Weblogic 6.1

          I am using the July 20th Beta build, weblogic610_bld_127633_sol.bin, running under
          Solaris OS 2.6.
          I have two basic questions:
          1. Why am I seeing the error I describe below.
          2. Will this problem be fixed either by:
          A. A new release of the iisproxy.dll accompanying Weblogic 6.1 GA release on July
          30th (I currently use the iisproxy.dll which accompanied Weblogic 6.0 sp 1).
          B. A fix in the jsp response handling of the application server in the GA release.
          When used with the iisproxy.dll, in Weblogic 6.1 a jsp can not contain code to
          alter the filename in the response it is returning based on a request. This functionality
          worked in both Weblogic 4.5 and Weblogic 6.0 sp2.
          I use the following code to send back a tab seperated value file with a variable
          filename from a jsp page.
          response.setHeader("Content-Disposition", "filename=" + strFileName ".tsv");
          response.setContentType("text/tab-separated-values");
          When hitting Weblogic Server directly, this code works fine in Weblogic 6.1.
          My browser presents me with a download prompt, with a default filename equal to
          the variable filename I am setting in the jsp page.
          When hitting Weblogic Server through iisproxy.dll, iisproxy.dll gets the response
          from the application server, ignores it, then repeatedly resends the request to
          the application server. It gives up after 6 "bad" responses, and returns
          "No backend server available for connection: timed out after 20 seconds.".
          The functionality was perfect with the identical iisproxy.dll used with either
          Weblogic 4.5 or Weblogic 6.0 sp2.
          Things I have already tried:
          I can't find a newer version of the iisproxy.dll than the one that came with Weblogic
          6.0 sp1 (This is the 696 KB one).
          I have confirmed that the exact line of code which breaks the iisproxy.dll is
          the line where you set the filename. The download prompt works fine if you don't
          try to alter the response to set a specific filename.
          I have confirmed that changing the file extension to .jsp while still trying to
          alter the filename fails.


As you said, it could be the WLS6 truststore which doesn't contain the certificate authority. Just check which files are used (cacerts, cacerts.jks,..), and maybe you can find it by checking the option startup : -Dweblogic.security.SSL.trustedCAKeyStore
It doesn't matter when the exception is triggered (you can do an explicit handshake, or just write in the socket and then wait for an implicit handshake)

SetHeader("Content-disposition ) does not work in NN

response.setHeader("Content-disposition", "attachment; filename="+ fileName + strExt);
works for IE 5.5 but not in netscape .
IE 5.5 shows the save as dialog box
NN4.79 display the contents
how can i get the save as dialog box in NN4.79

try adding response.setContentType("your_content_type...") just before calling response.setHeader("Content-disposition", ...).
It seems that netscape requires it.

Weblogic 12c Servlet Response - Special characters show up as question mark

My web app is running on Weblogic 12c (12.1.1) using WebWork + Hibernate. The program streams data (bytes making up a pdf) from a CLOB in an Oracle Database to the AsciiStream of the servlet output response. No exceptions are thrown, but the generated pdf contains blank pages. Comparing the bytes of the generated pdf, special characters are showing up as question marks.
Some of the bytes read in from the database contain 8 bits (correct data), but the bytes that the servlet return contain only 7 (all bytes with 8 bits become "1111111"). The number of bytes returned from the servlet is correct.
Code:
//Response is HttpServletResponse
response.setContentType("application/pdf");
response.setHeader("Content-Disposition", "inline; filename=\"test.pdf\"");
out = response.getOutputStream();
byte[] buf = new byte[16 * 1024];
InputStream in = clob.getAsciiStream();
int size = -1;
while ((size = in.read(buf)) != -1){
// buf contains the correct data
out.write(buf, 0, size);
// other exception handling code, etc
out.flush();
out.close();
"Correct" pdf byte example:
10011100
10011101
1010111
1001011
1101111
11011011
Incorrect pdf byte example:
111111
111111
1010111
1001011
1101111
111111
I have verified that the data read from the CLOB in the database IS correct. My guess is that the Weblogic server has some strange servlet settings that causes the bytes to be written to the servlet output stream incorrectly, or a character encoding issue. Any ideas?
Edited by: 944705 on Jul 26, 2012 10:17 AM

Solution found, I'll post the work around to those who might encounter the same problem.
Somewhere in the layers of technology (webwork or weblogic I'd guess), the servlet response is encoded into UTF-8 regardless. The encoding in the database was ISO-8859-1. Sending ISO encoded bytes by UTF-8 caused the conflicting character codes (anything above 127) to show up as undefined.
The fix is to decode the input byte array into ISO-8859 string, then encode that string into UTF-8, which can be send by Weblogic.
isoConvert = new String(buf, "ISO-8859-1");
out.write(isoConvert.getBytes("UTF-8"), 0, isoConvert.getBytes("UTF-8").length);

Response setHeader in scriptless manner?

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