Small optimization in fileinstall

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1310181 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/fileinstall/src/main/java/org/apache/felix/fileinstall/internal/DirectoryWatcher.java b/fileinstall/src/main/java/org/apache/felix/fileinstall/internal/DirectoryWatcher.java
index 1e8fc51..6797f96 100644
--- a/fileinstall/src/main/java/org/apache/felix/fileinstall/internal/DirectoryWatcher.java
+++ b/fileinstall/src/main/java/org/apache/felix/fileinstall/internal/DirectoryWatcher.java
@@ -42,6 +42,7 @@
 import java.util.Set;
 import java.util.jar.JarInputStream;
 import java.util.jar.Manifest;
+import java.util.regex.Pattern;
 
 import org.apache.felix.fileinstall.ArtifactInstaller;
 import org.apache.felix.fileinstall.ArtifactListener;
@@ -165,9 +166,10 @@
         {
             flt = new FilenameFilter()
             {
+                Pattern pattern = Pattern.compile(filter);
                 public boolean accept(File dir, String name)
                 {
-                    return name.matches(filter);
+                    return pattern.matcher(name).matches();
                 }
             };
         }