How to show file in GWT client side, instead of Downloading: - gwt

Question

I need little help to achieve this, in my app user can upload files to server and its stored as blob object, and now i need to show them to user up on there request.
What I am up to is show in below code,
On server side I put content to response:
(This code is implemented based on this blog post WaterTalks)
resp.setContentType("text/plain");
resp.setHeader("Content-Disposition", "attachment; filename=output.txt");
PrintWriter out = resp.getWriter();
out.println("This is the output content");
out.println("Probably something dynamic should go in here:::::");
PersistenceManager pm = null;
try {
pm = PMF.get().getPersistenceManager();
javax.jdo.Transaction transaction = pm.currentTransaction();
Extent e = pm.getExtent(WaterTalkFiles.class, true);
Iterator iter = e.iterator();
String returns = "";
WaterTalkFiles file = (WaterTalkFiles)iter.next();
Blob blob = file.getData();
byte[] buffer = blob.getBytes();
String s = new String(buffer);
out.println(s);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != pm)
pm.close();
}
Now in client side when user click show button i want to show the file content in browser, not to download it.
My client side code is:
showfilecontentButton.addClickHandler(new ClickHandler() {
#Override
public void onClick(ClickEvent event) {
String link = "/FileUploadByWaterTalks";
container.add(new HTML("ShowFile"));
}
});
The code above (Client side code) not showing content of file its just downloading the file.
But I don't want user to download it, I want show them the content of it.
And, do I have to configure something over here to work it out.
resp.setContentType("text/plain");
resp.setHeader("Content-Disposition", "attachment; filename=output.txt");
Hope you got what my problem is. Please be free to share your thoughts and solutions to achieve this.
Thanks.
UPDATED
Up on the bases of first answer here, I changed some portion of my code:
updated code sections are:
resp.setHeader("Pragma", "no-cache");
final String url = "http://127.0.0.1:8888/FileUploadByWaterTalks";
String name = "output.txt";
Anchor link1 = new Anchor(name);
RootPanel.get().add(link1);
link1.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
Frame f = new Frame(url);
f.setSize("600px", "400px");
f.getElement().getStyle().setBorderWidth(0, Unit.PX);
RootPanel.get().add(f);
}
});
But still the browser asking me to save the file instead of showing it in the browser itself.

Answer 1

First remove the 'Content-Disposition' in your servlet.
Second, use a GWT Anchor in your code and when the user clicks open the link in a new window or an iframe.
Here you have a example using new window, and another using iframe:
final String url = "http://gwtquery.googlecode.com/git/README.txt";
String name = "README.txt";
Anchor link1 = new Anchor(name);
RootPanel.get().add(link1);
link1.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
Window.open(url, "_blank", "");
}
});
Anchor link2 = new Anchor(name);
RootPanel.get().add(link2);
link2.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
Frame f = new Frame(url);
f.setSize("600px", "400px");
f.getElement().getStyle().setBorderWidth(0, Unit.PX);
RootPanel.get().add(f);
}
});
This approach works for any file which the browser is capable to display, but be sure that you send the appropriate Content-Type header (text/plain, text/html, image/png etc.)