Add support for symlinks in PlexusIoZipFileResourceCollection

Author: Plamen Totev

src/main/java/org/codehaus/plexus/archiver/zip/PlexusIoZipFileResourceCollection.java

@@ -18,6 +18,7 @@
 
 import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
 import org.apache.commons.compress.archivers.zip.ZipFile;
+import org.codehaus.plexus.components.io.functions.SymlinkDestinationSupplier;
 import org.codehaus.plexus.components.io.resources.AbstractPlexusIoArchiveResourceCollection;
 import org.codehaus.plexus.components.io.resources.EncodingSupported;
 import org.codehaus.plexus.components.io.resources.PlexusIoResource;
@@ -79,6 +80,59 @@ public URL getResource( String name )
     private static class ZipFileResourceIterator
         implements Iterator<PlexusIoResource>, Closeable
     {
+        private class ZipFileResource
+            extends PlexusIoURLResource
+        {
+            private ZipFileResource( ZipArchiveEntry entry )
+            {
+                super( entry.getName(), entry.getTime() == -1 ? PlexusIoResource.UNKNOWN_MODIFICATION_DATE : entry.getTime(),
+                    entry.isDirectory() ? PlexusIoResource.UNKNOWN_RESOURCE_SIZE : entry.getSize(),
+                    !entry.isDirectory(), entry.isDirectory(), true );
+            }
+
+            public URL getURL()
+                throws IOException
+            {
+                String spec = getName();
+                if ( spec.startsWith( "/" ) )
+                {
+                    // Code path for PLXCOMP-170. Note that urlClassloader does not seem to produce correct
+                    // urls for this. Which again means files loaded via this path cannot have file names
+                    // requiring url encoding
+                    spec = "./" + spec;
+                    return new URL( url, spec );
+                }
+                return urlClassLoader.getResource( spec );
+            }
+        }
+
+        private class ZipFileSymlinkResource
+            extends ZipFileResource
+            implements SymlinkDestinationSupplier
+        {
+            private final ZipArchiveEntry entry;
+
+            private ZipFileSymlinkResource( ZipArchiveEntry entry )
+            {
+                super( entry );
+
+                this.entry = entry;
+            }
+
+            @Override
+            public String getSymlinkDestination()
+                throws IOException
+            {
+                return zipFile.getUnixSymlink( entry );
+            }
+
+            @Override
+            public boolean isSymbolicLink()
+            {
+                return true;
+            }
+       }
+
         private final Enumeration<ZipArchiveEntry> en;
 
         private final URL url;
@@ -103,28 +157,10 @@ public boolean hasNext()
         public PlexusIoResource next()
         {
             final ZipArchiveEntry entry = en.nextElement();
-            long l = entry.getTime();
-            final long lastModified = l == -1 ? PlexusIoResource.UNKNOWN_MODIFICATION_DATE : l;
-            final boolean dir = entry.isDirectory();
-            final long size = dir ? PlexusIoResource.UNKNOWN_RESOURCE_SIZE : entry.getSize();
 
-            return new PlexusIoURLResource( entry.getName(), lastModified, size, !dir, dir, true )
-            {
-                public URL getURL()
-                    throws IOException
-                {
-                    String spec = getName();
-                    if ( spec.startsWith( "/" ) )
-                    {
-                        // Code path for PLXCOMP-170. Note that urlClassloader does not seem to produce correct
-                        // urls for this. Which again means files loaded via this path cannot have file names
-                        // requiring url encoding
-                        spec = "./" + spec;
-                        return new URL( url, spec );
-                    }
-                    return urlClassLoader.getResource( spec );
-                }
-            };
+            return entry.isUnixSymlink()
+                ? new ZipFileSymlinkResource( entry )
+                : new ZipFileResource( entry );
         }
 
         public void remove()

src/test/java/org/codehaus/plexus/archiver/zip/PlexusIoZipFileResourceCollectionTest.java

@@ -2,15 +2,18 @@
 
 import org.apache.commons.io.IOUtils;
 import org.codehaus.plexus.PlexusTestCase;
+import org.codehaus.plexus.components.io.functions.SymlinkDestinationSupplier;
 import org.codehaus.plexus.components.io.resources.*;
 
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.URL;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.Map;
 import java.util.Set;
 
 public class PlexusIoZipFileResourceCollectionTest
@@ -87,4 +90,39 @@ public void testFilesThatAreNotThere()
         }
     }
 
+    public void testSymlinkEntries()
+        throws Exception
+    {
+        File testZip = new File( getBasedir(), "src/test/resources/symlinks/symlinks.zip" );
+        Map<String, String> symLinks = new HashMap<String, String>();
+        symLinks.put( "symDir", "targetDir/" );
+        symLinks.put( "symLinkToDirOnTheOutside", "../dirOnTheOutside/" );
+        symLinks.put( "symLinkToTheOutside", "../onTheOutside.txt" );
+        symLinks.put( "symR", "fileR.txt" );
+        symLinks.put( "symW", "fileW.txt" );
+        symLinks.put( "symX", "fileX.txt" );
+        PlexusIoZipFileResourceCollection
+            prc = new PlexusIoZipFileResourceCollection();
+        prc.setFile( testZip );
+        final Iterator<PlexusIoResource> entries = prc.getEntries();
+        while ( entries.hasNext() )
+        {
+            final PlexusIoResource next = entries.next();
+            String symLinkTarget = symLinks.remove( next.getName() );
+            if ( symLinkTarget != null )
+            {
+                assertTrue( next.getName() + " must be symlink", next.isSymbolicLink() );
+                assertTrue( next instanceof SymlinkDestinationSupplier );
+                assertEquals( symLinkTarget,
+                    ( (SymlinkDestinationSupplier) next ).getSymlinkDestination() );
+            }
+            else
+            {
+                assertFalse( next.getName() + " must not be symlink", next.isSymbolicLink() );
+            }
+        }
+
+        assertTrue( symLinks.isEmpty() );
+    }
+
 }