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Thread: Problem with accessing resources in JAR

  1. #1
    Join Date
    Jun 2012
    Uppsala, Sweden
    Thanked 1 Time in 1 Post

    Post Problem with accessing resources in JAR

    Hi, I'm making a test program for resource loading inside a jar and I'm having problems.

    I've read that you should use ClassLoader or alternatively getClass() to access a file inside a jar. Since the method that i use to load the resource is static, I use ClassLoader.getSystemResource(String path).
    My program finds the file but says that the path contains invalid syntax for filenames or directory names. This is the code that I use to load my resources:

    String path = ClassLoader.getSystemResource(file).getPath();
    			try {
    				wave = WaveData.create(new BufferedInputStream(new FileInputStream(path)));
    			} catch (FileNotFoundException e) {
    			AL10.alBufferData(buffers.get(i), wave.format, wave.data, wave.samplerate);

    Yes, I'm loading soundfiles for OpenAL.

    Anyway, I should remind you that it actually finds the file but the path has invalid syntaxing. This is an example of the path I get when I run it in jar form:

    file:\C:\Users\name\development\jars\test.jar!\sou nds\test.wav

    I've tried to remove the "!" and I still get the same error. If i remove the "file:" it doesn't find the file. Note that the program runs fine when I'm running in Eclipse.

  2. #2
    Forum VIP
    Join Date
    Jul 2010
    Thanked 329 Times in 305 Posts

    Default Re: Problem with accessing resources in JAR

    Running fine in Eclipse is expected, since it is a closed environment and doesn't operate from a jar.
    What is the value of: file?
    Have you tried to get the resource with the ClassLoader's getResourceAsStream() method?
    It doesn't matter if the method is static, you can get the Class Object by saying: foo.class
    And then you can get the ClassLoader from the Class Object like you would with the getClass() method (I think, I haven't tried).

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  3. #3
    Member andbin's Avatar
    Join Date
    Dec 2013
    Thanked 122 Times in 114 Posts

    Default Re: Problem with accessing resources in JAR

    Quote Originally Posted by Dr.Code View Post
    String path = ClassLoader.getSystemResource(file).getPath();
    That getSystemResource returns an URL. Don't try to get path, remove parts or other tricks. An URL contains a resource specification in a particular format (especially for resources in jars!) and should be used only with APIs that deals correctly with URL objects.

    From ClassLoader use:
    public static InputStream getSystemResourceAsStream(String name)

    which gives an InputStream you can use instead of any trick you was trying with FileInputStream.
    Andrea, www.andbin.net SCJP 5 (91%) SCWCD 5 (94%)

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