Corrupt GZIP trailer

[Karen Gomes]

I'm trying to convert a log file to a gzip file, and another application will unzip the file to a log file. I have attached my class that does so below. This is the error I get :

------------------------------
1132 [Thread-0] INFO util.GZipUtil - in unzip func
1132 [Thread-0] INFO util.GZipUtil - input file name = 1098035357042.gzip
1132 [Thread-0] INFO util.GZipUtil - output file name = c:\aaa\logs\1098035357042.log
1162 [Thread-0] INFO util.GZipUtil - (int)file.length() = 105
java.io.IOException: Corrupt GZIP trailer
1162 [Thread-0] DEBUG util.GZipUtil - java.io.IOException: Corrupt GZIP trailer
1162 [Thread-0] INFO LoggingTask - unzippedFile - c:\aaa\logs\1098035357042.log
at java.util.zip.GZIPInputStream.readTrailer(Unknown Source)
at java.util.zip.GZIPInputStream.read(Unknown Source)
at java.io.FilterInputStream.read(Unknown Source)
at com.patronsolutions.messaging.util.GZipUtil.unzip(GZipUtil.java:108)
at LoggingTask.run(LogGateLinkInfo.java:131)
at java.util.TimerThread.mainLoop(Unknown Source)
at java.util.TimerThread.run(Unknown Source)
V10/1/20042:32:23 PMPARKGATE A110180060033846ERUD CODE-10110331221True

------------------------------

I did find a bug that says that the gzip has a bug if the inflated file size is >2GB then we get the above exception. In my case I get it even when the file size is 89 bytes. Also my data get altered after I have unzipped it.
Data before zipping:
V10/1/20042:32:23 PMPARKGATE A110180060033846BUD CODE-11110031221True

Data after unzipping:
V10/1/20042:32:23 PMPARKGATE A110180060033846ERUD CODE-10110331221True

Can anyone help me out with this? Should I use gzip or zip for this? How does one decide which one to use? I read that the zip(not gzip) also has a bug in java. What does this "Corrupt GZIP trailer" mean?

Here is my code:

 
 
import java.io.File;
import java.io.FileInputStream;
 
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
 

 
public class GZipUtil {
private final static Log log = LogFactory.getLog(GZipUtil.class);
File inputfile = null;
 

 
/**
 * This method will take the file passed to it and zip it
 * @param File - output file 
 */
public File gzip(File file) {
String outFilename = file.getAbsolutePath().substring(0,file.getAbsolutePath().indexOf("."))+".gzip";
File outputFile = new File(outFilename);
try {
        // Create the GZIP output stream
        GZIPOutputStream out = new GZIPOutputStream(new FileOutputStream(outputFile));
        log.info("in testgzip func : file = " + outFilename);
        // Open the input file
        String inFilename = file.getName();
        FileInputStream in = new FileInputStream(file);
    
        //log.info("Transfering bytes from the input file to the GZIP output stream");
        byte[] buf = new byte[(int)file.length()];
        //byte[] buf = new byte[];
        int len;
        log.info("(int)file.length() = "+(int)file.length());
        while ((len = in.read(buf)) > 0) {
            out.write(buf,0,len);
        }
        
        in.close();
        
        //log.info("Completed the GZIP file and exiting testzip func");
        out.finish();
        out.close();
        return (new File(outFilename));
    } catch (IOException e) {
    log.info(e);
    e.printStackTrace();
    }

    return outputFile;
}

/**
 * This method will take the file passed to it and unzip it
 */
public File unzip(File file) {
log.info("in unzip func");
GZIPInputStream in = null;
OutputStream out = null;
// Open the output file
String outFilename = file.getAbsolutePath().substring(0,file.getAbsolutePath().indexOf("."))+".log";
File unzipped = new File(outFilename);



log.info("input file name = "+ file.getName());
log.info("output file name = "+ outFilename);
try {

if (!unzipped.exists())unzipped.createNewFile();
// Open the compressed file
in = new GZIPInputStream(new FileInputStream(file));
out = new FileOutputStream(outFilename);

// Transfer bytes from the compressed file to the output file
log.info("(int)file.length() = "+(int)file.length());
byte[] buf = new byte[(int)file.length()];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}

// Close the file and stream
in.close();
out.close();
} catch (IOException e) {
log.debug(e);
e.printStackTrace();
}
catch (Exception e) {
log.debug(e);
e.printStackTrace();
}
return unzipped;
 
}


} 

Thanks
Karen

[Ajith Anand]

I'm afraid there is something in your program which you should give a second thought:

when you say
byte[] buf = new byte[(int)file.length()];

casting the file length to int , there are chances that you corrupt the stream for file sizes which are greater than
2148 MB , I think you will run into stream corruption in these cases....

[Roman Smolkin]

Hi, did you ever figure out a solution? I'm running into very similar issue (same error) but in a slightly different scenario...

I'm not even writing anything to file, just create the input and output streams and then send it back...

[Rob Spoor]

Neither Karen nor Ajith has been active for years, so I doubt you will get an answer from them.