Add support for symbolic links in tar file resource collections

Author: plamentotev

src/main/java/org/codehaus/plexus/archiver/tar/PlexusIoTarFileResourceCollection.java

@@ -54,7 +54,9 @@ public boolean hasNext()
             public PlexusIoResource next()
             {
                 final TarArchiveEntry entry = (TarArchiveEntry) en.nextElement();
-                return new TarResource( tarFile, entry );
+                return !entry.isSymbolicLink()
+                    ? new TarResource( tarFile, entry )
+                    : new TarSymlinkResource( tarFile, entry );
             }
 
             public void remove()

src/main/java/org/codehaus/plexus/archiver/tar/TarSymlinkResource.java

@@ -0,0 +1,32 @@
+package org.codehaus.plexus.archiver.tar;
+
+import java.io.IOException;
+
+import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
+import org.codehaus.plexus.components.io.functions.SymlinkDestinationSupplier;
+
+/**
+ * A {@link TarResource} that represents symbolic link.
+ */
+public class TarSymlinkResource
+    extends TarResource
+    implements SymlinkDestinationSupplier
+{
+    private final String symlinkDestination;
+
+    public TarSymlinkResource(TarFile tarFile, TarArchiveEntry entry) {
+        super(tarFile, entry);
+        symlinkDestination = entry.getLinkName();
+    }
+
+    @Override
+    public String getSymlinkDestination() throws IOException {
+        return symlinkDestination;
+    }
+
+    @Override
+    public boolean isSymbolicLink() {
+        return true;
+    }
+
+}

src/test/java/org/codehaus/plexus/archiver/tar/TarArchiverTest.java

@@ -34,6 +34,7 @@
 import org.codehaus.plexus.archiver.gzip.GZipCompressor;
 import org.codehaus.plexus.archiver.util.ArchiveEntryUtils;
 import org.codehaus.plexus.archiver.util.Compressor;
+import org.codehaus.plexus.archiver.util.DefaultArchivedFileSet;
 import org.codehaus.plexus.archiver.zip.ArchiveFileComparator;
 import org.codehaus.plexus.components.io.attributes.PlexusIoResourceAttributeUtils;
 import org.codehaus.plexus.components.io.attributes.PlexusIoResourceAttributes;
@@ -533,4 +534,21 @@ private void testCreateResourceCollection( TarHandler tarHandler )
         cmp1.close();
         cmp2.close();
     }
+
+    public void testSymlinkArchivedFileSet()
+        throws Exception
+    {
+        final File tarFile = getTestFile( "src/test/resources/symlinks/symlinks.tar" );
+        final File tarFile2 = getTestFile( "target/output/pasymlinks-archivedFileset.tar" );
+        final TarArchiver tarArchiver = getPosixTarArchiver();
+        tarArchiver.setDestFile( tarFile2 );
+        DefaultArchivedFileSet archivedFileSet = DefaultArchivedFileSet.archivedFileSet( tarFile );
+        archivedFileSet.setUsingDefaultExcludes( false );
+        tarArchiver.addArchivedFileSet( archivedFileSet );
+        tarArchiver.createArchive();
+
+        final TarFile cmp1 = new TarFile( tarFile );
+        final TarFile cmp2 = new TarFile( tarFile2 );
+        ArchiveFileComparator.assertEquals( cmp1, cmp2, "" );
+    }
 }