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Thread: How to specify FileOutputStream location?

  1. #1
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    Default How to specify FileOutputStream location?

    So I'm using the following code below to serialize my arraylist of obejcts. it is work except that I want to be able to specify where it outputs the file.

    I thought I could change:
    FileOutputStream fout = new FileOutputStream("AccList.dat");
    to something like:
    FileOutputStream fout = new FileOutputStream("C:\Program Files\test\AccList.dat");

    but then it just crashes. I kind of understand that its just declaring FileOutputStream as AccList.dat I think... But how do I specify a save location?

    says:
    Exception in thread "main" java.lang.Error: Unresolved compilation problem:
    Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \\ )


    public void SaveArray()
    	{
    		/* serialize arraylist */
    		try
    		{
    			System.out.println("serializing list");
    			FileOutputStream fout = new FileOutputStream("AccList.dat");
    			ObjectOutputStream oos = new ObjectOutputStream(fout);
    			oos.writeObject(AAL.accArray);
    			oos.close();
    		} catch (Exception e)
    		{
    			e.printStackTrace();
    		}
    	}// end SaveArray


  2. #2
    Super Moderator Json's Avatar
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    Default Re: How to specify FileOutputStream location?

    It's because the backslash is a special character in Java string land. You will need to escape it or turn it into a forwardslash.

    FileOutputStream fout = new FileOutputStream("C:\\Program Files\\test\\AccList.dat");
    OR

    FileOutputStream fout = new FileOutputStream("C:/Program Files/test/AccList.dat");
    That should do the trick.

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    Hallowed (May 25th, 2011)

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    Default Re: How to specify FileOutputStream location?

    You have been so helpful! Thank you!

    Now.. Any chance you have an ftp server I can host a read/write AccList.dat file? haha.
    I want to see if I can get my program to save over internet. =P
    Last edited by Hallowed; May 25th, 2011 at 11:49 PM.

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    Default Re: How to specify FileOutputStream location?

    Do you know why I wouldn't be able to load a picture from the internet for example: "http://i52.tinypic.com/307rt36.jpg"
    as an icon for a button? It just acts like there isn't one at all.
    well I guess not really cause it crashes if there is nothing there. but still?

    Icon sword1 = new ImageIcon ( ("http://i52.tinypic.com/307rt36.jpg"));

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    Default Re: How to specify FileOutputStream location?

    Do you know why I wouldn't be able to load a picture from the internet
    See the API for ImageIcon, it contains a constructor which accepts a URL object that you can use to specify the location
    try{
        Icon sword1 = new ImageIcon ( new URL("http://i52.tinypic.com/307rt36.jpg") );
    }catch(MalformedURLException e){
        e.printStackTrace();
    }

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    Hallowed (May 27th, 2011)

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    Default Re: How to specify FileOutputStream location?

    so I imported these:
    import java.net.MalformedURLException;
    import java.net.URL;
    and
    I put this into my code:
    try
    		{
    			Icon sword2 = new ImageIcon(new URL(
    					"http://i52.tinypic.com/307rt36.jpg"));
    		} catch (MalformedURLException e)
    		{
    			e.printStackTrace();
    		}

    But now this wont work.



    fancyJButton.setRolloverIcon(sword2); // set rollover image
    Exception in thread "main" java.lang.Error: Unresolved compilation problem:
    sword2 cannot be resolved to a variable

    at JTabbedPaneFrame.<init>(JTabbedPaneFrame.java:41)
    at JTabbedPaneDemo.main(JTabbedPaneDemo.java:9)


    I tried looking at the api before too but it didn't work for me when i tried it.
    I don't think I was doing it right cause all it said is:
    ImageIcon(URL location)

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    Default Re: How to specify FileOutputStream location?

    In the code you posted, the Icon 'sword2' is declared as a local variable inside the 'try' scope of a 'try..catch'. This means it is local to that block and disappears at the end, i.e. when the closing curly brace } is reached. If you want it to be accessible to other code, either put that other code inside the 'try' scope, i.e. after the 'sword2' declaration (this is how 'try...catch' is generally used), or move the declaration (but not the initialization) of 'sword2' outside the 'try' scope so it is in the scope of the code that wants to use it.

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    Hallowed (May 29th, 2011)

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    Default Re: How to specify FileOutputStream location?

    Thank you. Totally forgot about that for some reason. =/ I'll try it out.
    Works! =]
    Last edited by Hallowed; May 29th, 2011 at 06:38 PM.

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