A ZipEntry that was being retrieved through ZipInputStream.getNextEntry()
returns -1 when getCompressedSize() and getSize() are being asked.
I have tried this by creating an archive of an directory using jar -cvMf ...

Testcase:

import java.io.*;
import java.util.*;
import java.util.zip.*;

public class test extends Object
{
static public void main(String args[]) throws Exception {
ZipInputStream inzip = null;
ZipEntry entry = null;

inzip = new ZipInputStream(new FileInputStream("somearchive"));
while (true) {
entry = inzip.getNextEntry();
if (entry.getName().equals("somefile")) {
System.out.println(" Name: " +
entry.getName());
System.out.println("CSize: " +
entry.getCompressedSize());
System.out.println("USize: " +
entry.getSize());
break;
}
}
}
}