A strange problem about InputStream

Question

I meet a strange problem.
I have a data file named data.dat whose size is 16k.
I write a passage of code to read the binary data from data.dat
       byte[] gbData = new byte[8177 * 2];
       // it's length equals to the size of data.dat
       InputStream in = ClassLoader.getSystemResourceAsStream(
           "com/sunway/james/st/res/data.dat");
       in.read(gbData);
       in.close();When I run the program, It's can work well. Then I put all class and resources into a jar file.
When I run the jar file, I can only get first 600 (and serval more) bytes right. left bytes are 0.
Who can tell me what happen?

Answer 1

Thank you.
I tried to use java.nio to read the data, and there is still the problem.
flowing is the new codes:
        FileInputStream in =
            new FileInputStream("com/sunway/james/st/res/BIG5.dat");
        ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
        in.getChannel().read(buffer);
        byte[] big5Data = buffer.array();
        in.close();