FileSystemManager fsManager = VFS.getManager();
FileObject file = fsManager.resolveFile( "gz:tar:file:///extra/data/tryVfs/archive.tar!/tardir/content.txt.gz!content.txt" );

if (extractFile.getName().getExtension().equals("gz"))

if (manager.canCreateFileSystem(extractFile))
{
    FileObject innerFile = manager.createFileSystem(extractFile);
}

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>gov.noaa.eds</groupId>
    <artifactId>tryVfs</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Try apache commons vfs</name>
    <url>http://maven.apache.org</url>
    <build>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>gov.noaa.eds</groupId>
    <artifactId>tryVfs</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Try apache commons vfs</name>
    <url>http://maven.apache.org</url>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.5</source>
                    <target>1.5</target>
                </configuration>
            </plugin>
            <plugin>
                <!-- Usage: mvn assembly:assembly -->
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                    <archive>
                        <manifest>
                            <mainClass>gov.noaa.eds.tryVfs.MultiStep</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <dependencies>
        <dependency>
            <groupId>commons-vfs</groupId>
            <artifactId>commons-vfs</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
         <plugins>
   <groupId>junit</groupId>
         <plugin>
   <artifactId>junit</artifactId>
             <version>3<groupId>org.apache.8maven.1<plugins</version>groupId>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project>

/*
 * ExtractFromGzipInTar.java
 */
package gov.noaa.eds.tryVfs;

import org.apache.commons.vfs.AllFileSelector;
import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.FileSystemManager;
import org.apache.commons.vfs.FileType;
import org.apache.commons.vfs.FileTypeSelector;
import org.apache.commons.vfs.VFS;
import org.apache.commons.vfs.provider.local.LocalFile;

/**
 * Try using VFS to read the content of a compressed (gz) file inside of
 * a tar file. Extract tar file objects. If they are gzip files, decompress them.
 * Any directory structure in the tarfile is not being preserved, the contents
 * are pulled out to the same location regardless of directory hierarchy (for
 * the purposes of this example, all objects in the tar file have unique names,
 * so there are no file name conflicts).
 *
 * @author Ken Tanaka
 */
public class ExtractFromGzipInTar 
{
    FileSystemManager fsManager = null;
    static String extractDirname = "/extra/data/tryVfs";
    
    /**
     * Extract files from a tar file. If the file extracted is gzipped,
     * decompress it and remove the gzipped version.
     * @param args command line arguments are currently not used
     */
    public static void main( String[] args )
    {
        ExtractFromGzipInTar extract = new ExtractFromGzipInTar();throw new RuntimeException("failed to prepare extract directory " 
                    + extractDirname, ex);
        }
        
        
        /* Create a tarFile object */
        FileObject tarFile;
        try {
            System.out.println("Resolve tar file:");
            tarFile = msExtract.fsManager.resolveFile(
                    "tar:/extra/data/tryVfs/archive.tar");
            
            FileName tarFileName = tarFile.getName();
            System.out.println("  Path     : " + tarFileName.getPath());
            System.out.println("  URI      : " + tarFileName.getURI());
        } catch (Exception ex) {
            throw new RuntimeException("failed to open tar file ", ex);
        }
        
        /* Work on files inside tarFile */
        FileObject[] children;
        try {
            childrenextract.fsManager = tarFileVFS.getChildrengetManager();
        } catch (FileSystemException ex) {
            throw new RuntimeException("failed to get contentsfsManager offrom tarfile VFS", ex);
        }
        
        
        for (FileObject f : children) {
   /* Create a tarFile FileObject to connect to the tarfile on disk */
         msExtract.processChild(f)FileObject tarFile;
        }try {
        
    String  } tarName = new String("tar:file://" main( String[] args )+ extractDirname + "/archive.tar");
    
    private void processChild(FileObject f) {
    System.out.println("Resolve " + tarName);
     try {
      tarFile      if (f.getType() == FileType.FOLDER) {= extract.fsManager.resolveFile(tarName);
            
    // Recursively process files in this folder
  FileName tarFileName = tarFile.getName();
           FileObject[] children = f.getChildren();
 System.out.println("  Path     : " + tarFileName.getPath());
        for (FileObject subfile : children) {
  System.out.println("  URI      : " + tarFileName.getURI());
        } catch processChild(subfile);Exception ex) {
            throw new RuntimeException("failed to }
open tar file ", ex);
        }
  else {
     
        /* Work on FileNamefiles fnameinside = f.getName();tarFile */
        FileObject[] children;
       String extractNametry ={
 new String(this.extractDir.getName() + "/"
        children = tarFile.getChildren();
        } catch (FileSystemException ex) {
  + fname.getBaseName());
         throw new RuntimeException("failed to get contents  System.out.println("Extractingof tarfile " +, extractNameex);
        }
        
     LocalFile extractFile = (LocalFile) this.fsManager.resolveFile(extractName);
    for (FileObject f : children) {
            extractFileextract.copyFromprocessChild(f, new AllFileSelector());
        }
    } // main( String[] args )
    
    private        // if the file is gzipped, decompress it
    void processChild(FileObject f) {
        try {
            if (extractFilef.getNamegetType().getExtension().equals("gz")) == FileType.FOLDER) {
                // Recursively process files in this folder
    System.out.println("Decompressing " + extractName);
            FileObject[] children = f.getChildren();
             String gzName = newfor String("gz://" + extractFile.getName().getPath());(FileObject subfile : children) {
                    System.out.println("gzName=" + gzNameprocessChild(subfile);
                }
    FileObject gzFile = this.fsManager.resolveFile(gzName);
      } else {
                StringFileName fileNamefname = extractFilef.getName().getBaseName().replaceAll(".gz$", "");
                String extractName =  
    new String("file://" + extractDirname + "/"
                // The decompressed path we want
      + fname.getBaseName());
              String decompName = new String(this.extractDir.getName() + "/"  System.out.println("Extracting " + extractName);
                LocalFile extractFile =          + fileName(LocalFile) this.fsManager.resolveFile(extractName);
                
    
            // if the file is gzipped, decompress  // A temporary Directory
    it
/* line  90 */  if (extractFile.getName().getExtension().equals("gz")) {
                String tmpDirname = new String(thisSystem.extractDirout.getName()println("Decompressing " + "/" extractName);
                            + fileName + ".tmp");
                    // The uncompressed filename we seek
                    // A temporary file pathcontent.txt
                    String tmpFilenamefileName = new String(tmpDirname + "/" + fileNameextractFile.getName().getBaseName().replaceAll(".gz$", "");
                    
                    // Some debug lines
 // Build the direct path to the uncompressed content of the 
                     System.out.println("fileName   =" + fileName);
// gzip file in the tar file.
                     System.out.println("decompName =" + decompName);
   // gz:tar:file:///archive.tar!/tardir/content.txt.gz!content.txt
/* line 100 */      String gzName = new String("gz:" + fname.getURI()     System.out.println("tmpDirname =+ "!" + tmpDirnamefileName);
                    FileObject gzFile = Systemthis.outfsManager.println("tmpFilename=" + tmpFilenameresolveFile(gzName);
                    
                    // The decompressed path we want
 // Extracting from gzip file ends up with a directory containing what
        String decompName = new String("file://" + extractDirname + "/" 
   // we want.
                    LocalFile tmpDir = (LocalFile) this.fsManager.resolveFile(tmpDirname+ fileName);
                     tmpDir.copyFrom(gzFile, new FileTypeSelector(FileType.FILE))LocalFile decompFile = (LocalFile) this.fsManager.resolveFile(decompName);
                    
                    // MoveSome thedebug uncompressedlines
 file to the location desired.
               System.out.println("fileName     LocalFile tmpFile =" (LocalFile) this.fsManager.resolveFile(tmpFilename+ fileName);
                    LocalFile decompFileSystem.out.println("decompName =" (LocalFile) this.fsManager.resolveFile(+ decompName);
                    tmpFileSystem.out.moveTo(decompFileprintln("gzName=" + gzName);
                    
                    // Delete the temporary directory.Extracting
                    tmpDirdecompFile.deletecopyFrom(gzFile, new AllFileSelectorFileTypeSelector(FileType.FILE));
                } else {
   
                 // just extract the non-gzip file
         // Delete the gzip file now that we have the uncompressed version.
  extractFile.copyFrom(f, new AllFileSelector());
                }
  // Note that the plain file FileObject (extractFile) is used }
        } catch (FileSystemException ex) {
        // for deleting instead of the gzip FileObject (gzFile).
 ex.printStackTrace();
            throw new RuntimeException("Error working on tarfile object " + extractFilef.deletegetName(new AllFileSelector());
        }
    } // processChild(FileObject            }
            }
        } catch (FileSystemException ex) {
            ex.printStackTrace();
            throw new RuntimeException("Error working on tarfile object " + f.getName());
        }
    } // processChild(FileObject f)
}

f)
}

mvn assembly:assembly

java -jar target/tryVfs-1.0-SNAPSHOT-jar-with-dependencies.jar

Nov 7, 2007 12:22:01 PM org.apache.commons.vfs.VfsLog info
INFO: Using "/tmp/vfs_cache" as temporary files store.
Resolve tar:file:///extra/data/tryVfs/archive.tar
  Path     : /
  URI      : tar:file:///extra/data/tryVfs/archive.tar!/
Extracting file:///extra/data/tryVfs/non-gzip.txt
Extracting file:///extra/data/tryVfs/content.txt.gz
Decompressing file:///extra/data/tryVfs/content.txt.gz
fileName   =content.txt
decompName =file:///extra/data/tryVfs/content.txt
gzName=gz:tar:file:///extra/data/tryVfs/archive.tar!/tardir/content.txt.gz!content.txt