JSP - Checking if a file exists.

[croyce]

I am writing a web page, where I would like to check if an image exists on the server or not. ie..

if(imageExists(image1.gif))
{
   <img src='image1.gif'/>
}
else
{
   //Do nothing
}

Something like above.

I've tried...

File file1 = new file(image1.gif);
if(file1.exists()) do this;

but it always returns false, even when the image exists. ??

Any ideas?

 

[sedj]

When you say :

File f = new File("image.gif");

You are saying "create a file object where the file is located in my current working directory".
Now, if you started Tomcat from TOMCAT_HOME/bin - then that directory would be your current working directory.

If you started tomcat from "/home/user" then that would be the current working directory ... .and I'm guessing that neither of those directories is actually where your file is.

So the question is .... where is your file ?

--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[croyce]

Funny you should mention that, i've just tried this.. Still no joy.

String strPicUrl = "../images/07News/news" + id + "image1Thumb.jpg'"; 

File theFile = new File(application.getRealPath(strPicUrl));
													out.print("File Exists: " + theFile.exists() + "<br>");

The file is in my

http://www.url.com/images/07...etc..

the jsp file is being run from

http://www.url.com/admin/

(hence the ../ )

 

[croyce]

ServletContext app = getServletContext();

String path = app.getRealPath("");

File theFile = new File(path + "/images/07News/news/" + "news4image1.jpg");

out.print("File Exists: " + theFile.exists() + "<br>");

I've got to be close?

Cheers

 

[sedj]

String path = app.getRealPath("/");

Note the slash. That will return the base directory of your webapp - eg : TOMCAT_HOME/webapps/yourWebapp

Then build up the file path from that ...


--------------------------------------------------
Free Java/J2EE Database Connection Pooling Software

http://www.primrose.org.uk

 

[croyce]

ServletContext app = getServletContext();
String path1 = app.getRealPath("images/07News/news" + id + "image1Thumb.jpg");
File theImage1 = new File(path1);

String imageURL1 = "/images/noImage.gif";

if(theImage1.exists())
{
	imageURL1 = "../images/07News/news" + id + "image1Thumb.jpg";
}

Works perfectly, just posting an answer incase anyone else reads this thread. Coz that's the kinda guy I am lol.

Cheers for the help people.

Chris