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The following page has been changed by KenTanaka: http://wiki.apache.org/jakarta-commons/ExtractAndDecompressGzipFiles The comment on the change is: Added main code examples ------------------------------------------------------------------------------ There should be a cleaner, more direct route. Maybe someone more familiar with VFS can post better code. - This example uses Maven2. There is a pom.xml to define the project + This example uses Maven2. There is a '''{{{pom.xml}}}''' to define the project + {{{ + <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> + <groupId>junit</groupId> + <artifactId>junit</artifactId> + <version>3.8.1</version> + <scope>test</scope> + </dependency> + </dependencies> + </project> + }}} + + Content of '''{{{src/main/java/gov/noaa/eds/tryVfs/MultiStep.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). + * + * Use a multiple step approach. + * 1. extract gzipped file from tar file + * 2. decompress gzipped content to a temporary directory + * 3. move decompressed content to desired destination + * 4. remove temporary directory + * 5. remove gzipped file + * + * There should be a cleaner more direct route, but I haven't discovered it yet. + */ + public class MultiStep { + FileSystemManager fsManager = null; + static String extractDirname = "/extra/data/tryVfs"; + LocalFile extractDir = null; + + /** + * 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 ) { + MultiStep msExtract = new MultiStep(); + + try { + msExtract.fsManager = VFS.getManager(); + } catch (FileSystemException ex) { + throw new RuntimeException("failed to get fsManager from VFS", ex); + } + + try { + msExtract.extractDir = (LocalFile) msExtract.fsManager.resolveFile("file://" + + extractDirname); + if (! msExtract.extractDir.exists()) { + msExtract.extractDir.createFolder(); + } + } catch (FileSystemException ex) { + 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 { + children = tarFile.getChildren(); + } catch (FileSystemException ex) { + throw new RuntimeException("failed to get contents of tarfile ", ex); + } + + for (FileObject f : children) { + msExtract.processChild(f); + } + + } // main( String[] args ) + + private void processChild(FileObject f) { + try { + if (f.getType() == FileType.FOLDER) { + // Recursively process files in this folder + FileObject[] children = f.getChildren(); + for (FileObject subfile : children) { + processChild(subfile); + } + } else { + FileName fname = f.getName(); + String extractName = new String(this.extractDir.getName() + "/" + + fname.getBaseName()); + System.out.println("Extracting " + extractName); + LocalFile extractFile = (LocalFile) this.fsManager.resolveFile(extractName); + extractFile.copyFrom(f, new AllFileSelector()); + + // if the file is gzipped, decompress it + if (extractFile.getName().getExtension().equals("gz")) { + System.out.println("Decompressing " + extractName); + String gzName = new String("gz://" + extractFile.getName().getPath()); + System.out.println("gzName=" + gzName); + FileObject gzFile = this.fsManager.resolveFile(gzName); + String fileName = extractFile.getName().getBaseName().replaceAll(".gz$", ""); + + // The decompressed path we want + String decompName = new String(this.extractDir.getName() + "/" + + fileName); + + // A temporary Directory + String tmpDirname = new String(this.extractDir.getName() + "/" + + fileName + ".tmp"); + + // A temporary file path + String tmpFilename = new String(tmpDirname + "/" + fileName); + + // Some debug lines + System.out.println("fileName =" + fileName); + System.out.println("decompName =" + decompName); + System.out.println("tmpDirname =" + tmpDirname); + System.out.println("tmpFilename=" + tmpFilename); + + // Extracting from gzip file ends up with a directory containing what + // we want. + LocalFile tmpDir = (LocalFile) this.fsManager.resolveFile(tmpDirname); + tmpDir.copyFrom(gzFile, new FileTypeSelector(FileType.FILE)); + + // Move the uncompressed file to the location desired. + LocalFile tmpFile = (LocalFile) this.fsManager.resolveFile(tmpFilename); + LocalFile decompFile = (LocalFile) this.fsManager.resolveFile(decompName); + tmpFile.moveTo(decompFile); + + // Delete the temporary directory. + tmpDir.delete(new AllFileSelector()); + + // Delete the gzip file now that we have the uncompressed version. + // Note that the plain file FileObject (extractFile) is used + // for deleting instead of the gzip FileObject (gzFile). + extractFile.delete(new AllFileSelector()); + } + } + } catch (FileSystemException ex) { + ex.printStackTrace(); + throw new RuntimeException("Error working on tarfile object " + f.getName()); + } + } // processChild(FileObject f) + } + + }}} + --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
