Correctly handle symlinks transparently

Author: gnodet

src/main/java/org/codehaus/plexus/components/io/resources/PlexusIoFileResource.java

@@ -227,5 +227,10 @@ public boolean isSymbolicLink()
         return getAttributes().isSymbolicLink();
     }
 
+    protected DeferredFileOutputStream getDfos()
+    {
+        return dfos;
+    }
+
     private static final InputStreamTransformer identityTransformer = AbstractPlexusIoResourceCollection.identityTransformer;
 }

src/main/java/org/codehaus/plexus/components/io/resources/PlexusIoSymlinkResource.java

@@ -1,29 +1,94 @@
 package org.codehaus.plexus.components.io.resources;
 
+import org.apache.commons.io.output.DeferredFileOutputStream;
 import org.codehaus.plexus.components.io.attributes.PlexusIoResourceAttributes;
 import org.codehaus.plexus.components.io.attributes.SymlinkUtils;
 import org.codehaus.plexus.components.io.functions.SymlinkDestinationSupplier;
 
 import javax.annotation.Nonnull;
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Path;
 
 public class PlexusIoSymlinkResource
     extends PlexusIoFileResource
     implements SymlinkDestinationSupplier
 {
-    private final File symnlinkDestination;
+    private final String symLinkDestination;
+    private final PlexusIoResource targetResource;
 
     PlexusIoSymlinkResource( @Nonnull File symlinkfile, String name, @Nonnull PlexusIoResourceAttributes attrs )
         throws IOException
     {
         super( symlinkfile, name, attrs );
-        this.symnlinkDestination = null;
+        Path path = symlinkfile.toPath();
+        Path linkPath = java.nio.file.Files.readSymbolicLink( path );
+        symLinkDestination = linkPath.toString();
+        targetResource = ResourceFactory.createResource( path.resolveSibling( linkPath ).toFile() );
     }
 
     public String getSymlinkDestination()
         throws IOException
     {
-        return symnlinkDestination == null ? SymlinkUtils.readSymbolicLink( getFile() ).getPath() : symnlinkDestination.getPath();
+        return targetResource.getName();
+    }
+
+    public PlexusIoResource getTarget()
+    {
+        return targetResource;
+    }
+
+    public PlexusIoResource getLink() throws IOException
+    {
+        return new PlexusIoFileResource( getFile(), getName(), getAttributes() );
+    }
+
+    @Override
+    public long getSize()
+    {
+        DeferredFileOutputStream dfos = getDfos();
+        if ( dfos == null )
+        {
+            return targetResource.getSize();
+        }
+        else if ( dfos.isInMemory() )
+        {
+            return dfos.getByteCount();
+        }
+        else
+        {
+            return dfos.getFile().length();
+        }
+    }
+
+    @Override
+    public boolean isDirectory()
+    {
+        return targetResource.isDirectory();
+    }
+
+    @Override
+    public boolean isExisting()
+    {
+        return targetResource.isExisting();
+    }
+
+    @Override
+    public boolean isFile()
+    {
+        return targetResource.isFile();
+    }
+
+    @Override
+    public long getLastModified()
+    {
+        return targetResource.getLastModified();
+    }
+
+    @Nonnull
+    @Override
+    public PlexusIoResourceAttributes getAttributes()
+    {
+        return super.getAttributes();
     }
 }

src/test/java/org/codehaus/plexus/components/io/resources/PlexusIoPlexusIoFileResourceTest.java

@@ -21,7 +21,7 @@ public void testRealSymlink()
         final File file = new File( "src/test/resources/symlinks/src/symDir" );
         PlexusIoResourceAttributes attrs = FileAttributes.uncached( file );
         assertTrue( attrs.isSymbolicLink() );
-        PlexusIoFileResource r = new PlexusIoFileResource( file, "symDir", attrs );
+        PlexusIoResource r = ResourceFactory.createResource( file );
         assertTrue( r.isSymbolicLink() );
         assertTrue( r.isDirectory() );
         final File target = SymlinkUtils.readSymbolicLink( file );