How to get Java web application path?

Question

I have a fileupload servlet in java. And i want to set path to upload folder, to it waork on any server. I say:

 File disk = new File("/myportlet/upload/"+item.getName());
 item.write(disk);

But nothing saved. When i use absolute path to upload folder all work fine.
So how to set path to upload folder in server?

You should be aware that you violate the servlet spec by wanting to write inside the server. — Thorbjørn Ravn Andersen
– Thorbjørn Ravn Andersen, Commented Dec 19, 2012 at 12:15
Look at the path. If the applet runs on linux, the first slash would set you to the root. Try ./myportlet/upload/ — looper
– looper, Commented Dec 19, 2012 at 12:18
This probably fails due to / being interpreted as "root of filesystem" in the File() constructor. As Thorbjørn writes above, you're violating the spec if you actually write to the server area. I'd suggest using a welldefined space on the filesystem for these files instead. — Thomas
– Thomas, Commented Dec 19, 2012 at 12:18
@looper you are not guaranteed that the current working directory is set to anything useful to you. — Thorbjørn Ravn Andersen
– Thorbjørn Ravn Andersen, Commented Dec 19, 2012 at 12:21

Isaac · Accepted Answer · 2012-12-19 12:37:24Z

2

The leading "/" at the new File() constructor refers to the root of the file system. The file will be written into a directory named /myportlet/upload, in your code.

As the comments implied, writing into appserver-internal directories violates the spec and is generally a terrible idea - I honestly can't think of one proper use for doing so. What you want to do is to read the target path from a parameter - for example, a servlet's initialization parameter or a context initialization parameter - and use that.

edited Dec 19, 2012 at 12:37

answered Dec 19, 2012 at 12:32

Isaac

16.8k5 gold badges63 silver badges83 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Kliver Max Over a year ago

servlet's initialization parameter or a context initialization parameter - and use that. Can you give a example? Im not good in java.

Isaac Over a year ago

Google is your best friend here... :-) see this for example: tutorials.jenkov.com/java-servlets/web-xml.html#initParams

Sainatha Reddy Rajanala · Accepted Answer · 2012-12-19 12:33:48Z

2

I used the below snippet. It worked fine in windows server.

File f=new File("sample.xls");
        f.createNewFile();
        FileOutputStream fos=null;
        if(f != null){
            fos=new FileOutputStream(f);
            fos.write(b);
            fos.flush();
            fos.close();
        }

answered Dec 19, 2012 at 12:33

Sainatha Reddy Rajanala

2921 gold badge3 silver badges13 bronze badges

Collectives™ on Stack Overflow

How to get Java web application path?

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related