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Hi Abuzar,
I recently did a project where I needed to use a temporary folder to store some things on the file system. To create the temp folder I used:

<span class="hljs-keyword">Path</span> newTempDir&nbsp;= Files.createTempDirectory(<span class="hljs-string">"newTempDirPrefix"</span>);
<span class="hljs-keyword">File</span> newTempFile = new <span class="hljs-keyword">File</span>(newTempDir, <span class="hljs-string">"newTempFile.txt"</span>);

The above code creates a temporary folder in the location defined by the java.io.tmpdir system property.

But I could have also used the app server temp dir property (and that might be a better option):

File tempDir = (File) FacesContext<span class="hljs-preprocessor">.getCurrentInstance</span>()
    <span class="hljs-preprocessor">.getExternalContext</span>()<span class="hljs-preprocessor">.getApplicationMap</span>()<span class="hljs-preprocessor">.get</span>(ServletContext<span class="hljs-preprocessor">.TEMPDIR</span>)<span class="hljs-comment">;</span>
File newTempFile = new File(tempDir, <span class="hljs-string">"newTempFile.txt"</span>)<span class="hljs-comment">;</span>

Is there a reason that you cannot use one of these techniques?

For more information on creating and using temporary directories in web/portlet applications, check out this excellent StackOverflow post by BalusC: https://stackoverflow.com/questions/31255366/how-to-save-generated-file-temporarily-in-servlet-based-web-application. It's also worth checking out his related Q&A on getRealPath() (he essentially says that you should never use getRealPath()): https://stackoverflow.com/questions/12160639/what-does-servletcontext-getrealpath-mean-and-when-should-i-use-it.

- Kyle

Abuzar Rana:

I'm trying to keep (store) files into $TOMCAT_HOME/webapps/projectnamefolder/temp I've created folder manually inside webapps because I'm storing files into that folder.

This is completely discouraged and very much unsupported by app servers. The webapp is not meant to be yours to to modify, it is the purview of the application server itself.

Tomcat has always been known to be a little lax at its assertion of ownership on that folder allowing, for example, direct modification to files in the exploded war directory.

That said, you still shouldn't do it.