Promoting this common pattern into a convenience class

core/src/main/java/jenkins/ReflectiveFilePathFilter.java

@@ -0,0 +1,45 @@
+package jenkins;
+
+import java.io.File;
+
+/**
+ * Convenient adapter for {@link FilePathFilter} that allows you to handle all
+ * operations as a single string argument.
+ *
+ * @author Kohsuke Kawaguchi
+ * @since 1.THU
+ */
+public abstract class ReflectiveFilePathFilter extends FilePathFilter {
+
+    protected abstract boolean op(String name, File path) throws SecurityException;
+
+    @Override
+    public boolean read(File f) throws SecurityException {
+        return op("read", f);
+    }
+
+    @Override
+    public boolean write(File f) throws SecurityException {
+        return op("write", f);
+    }
+
+    @Override
+    public boolean mkdirs(File f) throws SecurityException {
+        return op("mkdirs", f);
+    }
+
+    @Override
+    public boolean create(File f) throws SecurityException {
+        return op("create", f);
+    }
+
+    @Override
+    public boolean delete(File f) throws SecurityException {
+        return op("delete", f);
+    }
+
+    @Override
+    public boolean stat(File f) throws SecurityException {
+        return op("stat", f);
+    }
+}

core/src/main/java/jenkins/security/DefaultFilePathFilter.java

@@ -26,7 +26,7 @@ package jenkins.security;
 
 import hudson.Extension;
 import hudson.remoting.ChannelBuilder;
-import jenkins.FilePathFilter;
+import jenkins.ReflectiveFilePathFilter;
 import org.kohsuke.accmod.Restricted;
 import org.kohsuke.accmod.restrictions.DoNotUse;
 
@@ -65,8 +65,8 @@ import java.util.logging.Logger;
 
     @Override
     public void onChannelBuilding(ChannelBuilder builder, Object context) {
-        new FilePathFilter() {
-            private boolean op(String op, File f) throws SecurityException {
+        new ReflectiveFilePathFilter() {
+            protected boolean op(String op, File f) throws SecurityException {
                 if (BYPASS_LOG != null) {
                     BYPASS_LOG.println(op + " " + f);
                     return true;
@@ -80,24 +80,6 @@ import java.util.logging.Logger;
                     return false;
                 }
             }
-            @Override public boolean read(File f) throws SecurityException {
-                return op("read", f);
-            }
-            @Override public boolean write(File f) throws SecurityException {
-                return op("write", f);
-            }
-            @Override public boolean mkdirs(File f) throws SecurityException {
-                return op("mkdirs", f);
-            }
-            @Override public boolean create(File f) throws SecurityException {
-                return op("create", f);
-            }
-            @Override public boolean delete(File f) throws SecurityException {
-                return op("delete", f);
-            }
-            @Override public boolean stat(File f) throws SecurityException {
-                return op("stat", f);
-            }
         }.installTo(builder);
     }
 }