GZIPContentEncodingFilter: Object header values

jersey-server/src/main/java/com/sun/jersey/api/container/filter/GZIPContentEncodingFilter.java

@@ -146,7 +146,7 @@ public ContainerResponse filter(ContainerRequest request, ContainerResponse resp
         response.getHttpHeaders().add(HttpHeaders.VARY, HttpHeaders.ACCEPT_ENCODING); // add vary header
 
         String acceptEncoding = request.getRequestHeaders().getFirst(HttpHeaders.ACCEPT_ENCODING);
-        String contentEncoding = (String) response.getHttpHeaders().getFirst(HttpHeaders.CONTENT_ENCODING);
+        Object contentEncoding = response.getHttpHeaders().getFirst(HttpHeaders.CONTENT_ENCODING);
 
         if (acceptEncoding != null && contentEncoding == null && acceptEncoding.contains("gzip")) {
             // Check EntityTag header

jersey-server/src/test/java/com/sun/jersey/server/api/container/filter/GZIPContentEncodingFilterTest.java

@@ -0,0 +1,67 @@
+package com.sun.jersey.server.api.container.filter;
+
+import com.sun.jersey.api.container.filter.GZIPContentEncodingFilter;
+import com.sun.jersey.core.header.InBoundHeaders;
+import com.sun.jersey.server.impl.application.WebApplicationImpl;
+import com.sun.jersey.spi.container.ContainerRequest;
+import com.sun.jersey.spi.container.ContainerResponse;
+import com.sun.jersey.spi.container.ContainerResponseWriter;
+import org.junit.Test;
+
+import javax.ws.rs.core.HttpHeaders;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.util.Locale;
+
+/**
+ * @author Mark Fulton
+ */
+public class GZIPContentEncodingFilterTest {
+    @Test
+    public void containerResponseFilterSupportsObjectResponseHeaderValues() {
+        WebApplicationImpl webApplication = new WebApplicationImpl();
+        String method = "PUT";
+        URI baseUri = URI.create("base/uri");
+        URI requestUri = URI.create("request/uri");
+        InBoundHeaders headers = new InBoundHeaders();
+        headers.add(HttpHeaders.ACCEPT_ENCODING, "gzip");
+        ByteArrayInputStream entity = new ByteArrayInputStream("entity".getBytes(StandardCharsets.UTF_8));
+        ContainerRequest request = new ContainerRequest(webApplication, method, baseUri, requestUri, headers, entity);
+        ContainerResponse response = new ContainerResponse(webApplication, request, createResponseWriter());
+        response.getHttpHeaders().putSingle(HttpHeaders.CONTENT_ENCODING, ContentEncoding.GZIP);
+        new GZIPContentEncodingFilter().filter(request, response);
+    }
+
+    private ContainerResponseWriter createResponseWriter() {
+        return new ContainerResponseWriter() {
+            @Override
+            public OutputStream writeStatusAndHeaders(long contentLength, ContainerResponse response)
+                    throws IOException {
+                return new ByteArrayOutputStream();
+            }
+
+            @Override
+            public void finish() throws IOException {
+            }
+        };
+    }
+
+    /**
+     * @author Mark Fulton
+     */
+    private enum ContentEncoding {
+        GZIP,
+        COMPRESS,
+        DEFLATE,
+        IDENTITY;
+
+        @Override
+        public String toString() {
+            return super.toString().toLowerCase(Locale.ENGLISH);
+        }
+    }
+}