How to create a file using java in a webapp?

Question

I am trying to make a webapps which creates a file in a specific folder. This app should work both on windows and ubuntu but they have different file structures. So how do I mention path in creation of file and again in Ubuntu I also need to use permissions. How can I give permissions to the folder in which I am trying to create a file. I am using java for this and this is my code:

 //bfr=new BufferedReader(new InputStreamReader(System.in));
 String fileName="/home/hemant/"+credentials[3];
 String content=String.valueOf(n)+"\n"+messages.length;
 File file=new File(fileName);       
 if(!file.exists()){
      System.out.println("filecreated");
      file.createNewFile();
 }

my app is a tomcat based app. What should I do? I am new to this and don't have any idea.

Try using a properties file, or `System.getProperty("os.name");` in a pinch. — Elliott Frisch, Jun 25 '14 at 06:09
Assuming you're wanting to save files server-side then this question is basically a duplicate of http://stackoverflow.com/a/2663855/3651800 (although that answer basically says "don't do this") — Matt Coubrough, Jun 25 '14 at 06:12

score 0 · Answer 1 · answered Jun 25 '14 at 06:11

0

If you are using servlet,you can find path using this -

String path = servletConfig.getServletContext().getRealPath("/WEB-INF")

It will work on Ubantu and WIndows.

answered Jun 25 '14 at 06:11

Ninad Pingale

6,801
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score 0 · Answer 2 · answered Jun 25 '14 at 06:14

0

You can check operating system, on which your webapp is deployed by:

System.getProperty("os.name");

You can create file accordingly , For giving permissions to file , full control over file attributes is available in Java 7, as part of the "new" New IO facility (NIO.2)

Or you can checkout this link for more information : http://www.mkyong.com/java/how-to-set-the-file-permission-in-java/

answered Jun 25 '14 at 06:14

Abhijeet Panwar

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Actually I want to change the permission of folder to 777 where I am creating the file so that it can be created without any problem.. – cooljohny Jun 25 '14 at 06:22
Refer this article : http://www.journaldev.com/855/how-to-set-file-permissions-in-java-easily-using-java-7-posixfilepermission you can also write your native code in java to change permissions of that folder. – Abhijeet Panwar Jun 25 '14 at 06:26

score 0 · Accepted Answer · answered Jun 25 '14 at 06:15

You can get the information of Operating System using this code :

public class OSValidator {

    private static String OS = System.getProperty("os.name").toLowerCase();

    public static void main(String[] args) {

        System.out.println(OS);

        if (isWindows()) {
            System.out.println("This is Windows");
        } else if (isMac()) {
            System.out.println("This is Mac");
        } else if (isUnix()) {
            System.out.println("This is Unix or Linux");
        } else if (isSolaris()) {
            System.out.println("This is Solaris");
        } else {
            System.out.println("Your OS is not support!!");
        }
    }

    public static boolean isWindows() {

        return (OS.indexOf("win") >= 0);

    }

    public static boolean isMac() {

        return (OS.indexOf("mac") >= 0);

    }

    public static boolean isUnix() {

        return (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.indexOf("aix") > 0 );

    }

    public static boolean isSolaris() {

        return (OS.indexOf("sunos") >= 0);

    }

}

What abt the permissions part.I want to give all the permissions to the folder I am creating the file in so that the file is created without any problem.. — cooljohny, Jun 25 '14 at 06:23
give the permission to folder you can visit this link http://stackoverflow.com/questions/664432/how-do-i-programmatically-change-file-permissions — Keval Trivedi, Jun 25 '14 at 06:29

How to create a file using java in a webapp?

3 Answers3