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Thread: Keeping Variable Values

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    Default Keeping Variable Values

    Hello, I was just wondering if it's possible to keep the variable values every time someone runs the program without using anything web based. So for example: x=0, when the person runs the program x=1. The next time the person starts that program I want x to = 1. Is this possible?


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    Default Re: Keeping Variable Values

    It may be. If you read in the values from a text file. The trouble is that they'd have to have the text file I think somewhere on their computer. Also, if they got rid of it or it wasn't in the same directory as the text file, it couldn't find it. Also, I fear that you'd have to create a text file to start with.

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    The_Mexican (November 26th, 2010)

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    Default Re: Keeping Variable Values

    Thank you, this works.

    EDIT: Okay, so this now brings up the problem of being able to always have the location of the file the same. So for me it would be C:\\UserName\ThisPartIsProbablyTheSame but how do I get the name given to the username each time? Is that possible?
    Last edited by The_Mexican; November 26th, 2010 at 04:18 PM.

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    Default Re: Keeping Variable Values

    You would have to keep track of what OS the user is running (see: Find Operating Systems Information,Java Code to Get Operating System Information)

    Depending on their OS, where the standard user data location is different, and how to get this information is also different.

    Ex.:
    For windows 7 (possibly older versions of Windows too, don't know about this for sure), you can find the user's profile with the environment variable USERPROFILE

    System.out.println("The current user's profile is located at " + System.getenv("USERPROFILE"));

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    Default Re: Keeping Variable Values

    Thanks! I solved the problem using:
    (System.getenv("USERPROFILE")+"\\Downloads\\txtfile.txt"));
    I haven't actually tested this, but I assume it'll work for at least all windows users.

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    Default Re: Keeping Variable Values

    Load the file relative to the application and not he users hard drive, this will remove any platform specific paths. Simply create a dummy file, then do some string operations to get the true file's path...assuming your application is distributed as a jar:
    File file = new File("temp");//create a file - this will be in the same directory as your jar
    String dir = file.getAbsolutePath().substring(0, file.getAbsolutePath().length() - 4 );//remove the temp - this gives you the directory
    File myFile = new File(dir + "myfilename.txt" );
    //read file, or create a new one if it does not exist

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    The_Mexican (November 27th, 2010)

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    Default Re: Keeping Variable Values

    Ah thanks copeg! So this will make it so that no matter where the text file resides, the program will find it, cool.

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