Hi all,
I'm working on something that requires a static array of almost 400k.
I figured that the best way to initialize this array would be to
compress the data, add a static array with an initializer to put the
compressed data there (gzip compresses it to about 22k, which seems
reasonable), and then add a static {} block that uses java.util.zip
to decompress this data.
Here's the code, edited for clarity:
import java.util.zip.*;
public class MyClass
{
private static final byte myGzippedData =
{
31, -117, 8, 8, -3, -3, 14, 54, 0, 3, 97, 0, -19, 93, 11,
-126, -37, -86, 14, -35, 42, 60, 46, -39, -1, 18, -34, 88, 31,
// and so on and so on... 22426 bytes in all
}
private static byte[] myData;
static
{
Inflater inf = new Inflater(true);
myData = new byte[368212];
inf.setInput(myGzippedData, 0, myGzippedData.length);
try
{
inf.inflate(myData);
}
catch (DataFormatException e) {}
}
public static void main(String[] argv)
{
for (int i=0; i<myData.length; i++)
{
System.out.write(myData[i]);
}
}
}
I'm having all sorts of problems with this. First of all, it just
doesn't work. Inflater.inflate() throws a DataFormatException with
message "invalid block type" (the initializer for myGzippedData was
generated from a .gz file, and if I dump that data to System.out
using write(), and pipe that to gunzip, it works fine).
Also, the .class file is huge -- more than 330k. I would expect an
initializer that initializes a 22k-array to add only slightly more
than 22k to the class file! What's going on?
If I could solve these to problems, I would be a happy camper once
again; but I was also thinking of a different approach: I could put
the data into a separate file, and read that to initialize the array;
I wouldn't even worry about compressing that file, because everything
will eventually be put into a jar file, and that will take care of
that. But that leads to the next problem: how do I read a file from
the jar containing my package, if possible in such a way that the same
code will work for an application, *and* if this jar is loaded as an
applet? If someone could share some working code to do that, or point
me to an example, I would be very grateful!
AtDhVaAnNkCsE!
- Thomas
