[UNDERTOW-1950] Fix NullPointerException in PreCompressedResourceSupplier

core/src/main/java/io/undertow/server/handlers/resource/PreCompressedResourceSupplier.java

@@ -54,20 +54,19 @@ public PreCompressedResourceSupplier(ResourceManager resourceManager) {
 
     @Override
     public Resource getResource(HttpServerExchange exchange, String path) throws IOException {
-        Resource originalResource = resourceManager.getResource(path);
         if(exchange.getRequestHeaders().contains(Headers.RANGE)) {
             //we don't use serve pre compressed resources for range requests
-            return originalResource;
+            return resourceManager.getResource(path);
         }
-        Resource resource = getEncodedResource(exchange, path, originalResource);
+        Resource resource = getEncodedResource(exchange, path);
         if(resource == null) {
-            return originalResource;
+            return resourceManager.getResource(path);
         }
         return resource;
     }
 
 
-    private Resource getEncodedResource(final HttpServerExchange exchange, String path, Resource originalResource) throws IOException {
+    private Resource getEncodedResource(final HttpServerExchange exchange, String path) throws IOException {
         final List<String> res = exchange.getRequestHeaders().get(Headers.ACCEPT_ENCODING);
         if (res == null || res.isEmpty()) {
             return null;
@@ -118,7 +117,13 @@ public List<Resource> list() {
 
                             @Override
                             public String getContentType(MimeMappings mimeMappings) {
-                                return originalResource.getContentType(mimeMappings);
+                                String fileName = resource.getName();
+                                String originalFileName = fileName.substring(0, fileName.length() - extension.length());
+                                int index = originalFileName.lastIndexOf('.');
+                                if (index != -1 && index != originalFileName.length() - 1) {
+                                    return mimeMappings.getMimeType(originalFileName.substring(index + 1));
+                                }
+                                return null;
                             }
 
                             @Override

core/src/test/java/io/undertow/server/handlers/file/PreCompressedResourceTestCase.java

@@ -102,13 +102,72 @@ public void testContentEncodedResource() throws IOException, URISyntaxException
             generatePreCompressedResource("gz");
 
             //assert compressed response that was pre compressed
-            assertResponse(compClient.execute(get), true, plainResponse, "gz");
+            assertResponse(compClient.execute(get), true, plainResponse, "gz", "text/html");
 
         } finally {
             client.getConnectionManager().shutdown();
         }
     }
 
+    @Test
+    public void testContentEncodedJsonResource() throws IOException, URISyntaxException {
+        HttpGet get = new HttpGet(DefaultServer.getDefaultServerURL() + "/path/data1.json");
+        TestHttpClient client = new TestHttpClient();
+        Path rootPath = Paths.get(getClass().getResource("data1.json").toURI()).getParent();
+
+        try (CloseableHttpClient compClient = HttpClientBuilder.create().build()){
+            DefaultServer.setRootHandler(new CanonicalPathHandler()
+                    .setNext(new PathHandler()
+                            .addPrefixPath("/path", new ResourceHandler(new PreCompressedResourceSupplier(new PathResourceManager(rootPath, 10485760)).addEncoding("gzip", ".gz"))
+                                    .setDirectoryListingEnabled(true))));
+
+            //assert response without compression
+            final String plainResponse = assertResponse(client.execute(get), false, null, "web", "application/json");
+
+            //assert compressed response, that doesn't exists, so returns plain
+            assertResponse(compClient.execute(get), false, plainResponse, "web", "application/json");
+
+            //generate compressed resource with extension .gz
+            Path json = rootPath.resolve("data1.json");
+            generateGZipFile(json, rootPath.resolve("data1.json.gz"));
+
+            //assert compressed response that was pre compressed
+            assertResponse(compClient.execute(get), true, plainResponse, "gz", "application/json");
+
+        } finally {
+            client.getConnectionManager().shutdown();
+        }
+    }
+
+    @Test
+    public void testContentEncodedJsonResourceWithoutUncompressed() throws IOException, URISyntaxException {
+        HttpGet get = new HttpGet(DefaultServer.getDefaultServerURL() + "/path/data3.json");
+        TestHttpClient client = new TestHttpClient();
+        Path rootPath = Paths.get(getClass().getResource("data2.json").toURI()).getParent();
+
+        try (CloseableHttpClient compClient = HttpClientBuilder.create().build()){
+            DefaultServer.setRootHandler(new CanonicalPathHandler()
+                    .setNext(new PathHandler()
+                            .addPrefixPath("/path", new ResourceHandler(new PreCompressedResourceSupplier(new PathResourceManager(rootPath, 10485760)).addEncoding("gzip", ".gz"))
+                                    .setDirectoryListingEnabled(true))));
+
+            //generate compressed resource with extension .gz and delete the uncompressed
+            Path json = rootPath.resolve("data2.json");
+            Path jsonFileToBeZippedAndDeleted = rootPath.resolve("data3.json");
+            Files.copy(json, jsonFileToBeZippedAndDeleted);
+            // data3.json.gz has no corresponding data3.json in the filesystem (UNDERTOW-1950)
+            generateGZipFile(jsonFileToBeZippedAndDeleted, rootPath.resolve("data3.json.gz"));
+            Files.delete(jsonFileToBeZippedAndDeleted);
+
+            //assert compressed response even with missing uncompressed
+            assertResponse(compClient.execute(get), true, null, "gz", "application/json");
+
+        } finally {
+            client.getConnectionManager().shutdown();
+        }
+    }
+
+
     @Test
     public void testCorrectResourceSelected() throws IOException, URISyntaxException {
         HttpGet get = new HttpGet(DefaultServer.getDefaultServerURL() + "/path/page.html");
@@ -136,7 +195,7 @@ public void testCorrectResourceSelected() throws IOException, URISyntaxException
             generatePreCompressedResource("gzip.nonsense");
 
             //assert compressed response that was pre compressed
-            assertResponse(compClient.execute(get), true, plainResponse, "gzip");
+            assertResponse(compClient.execute(get), true, plainResponse, "gzip", "text/html");
 
         } finally {
             client.getConnectionManager().shutdown();
@@ -166,21 +225,21 @@ private void replaceStringInFile(Path file, String original, String replacement)
     }
 
     private String assertResponse(HttpResponse response, boolean encoding) throws IOException {
-        return assertResponse(response, encoding, null, null);
+        return assertResponse(response, encoding, null, null, "text/html");
     }
 
     private String assertResponse(HttpResponse response, boolean encoding, String compareWith) throws IOException {
-        return assertResponse(response, encoding, compareWith, "web");
+        return assertResponse(response, encoding, compareWith, "web", "text/html");
     }
 
     /**
      * Series of assertions checking response code, headers and response content
      */
-    private String assertResponse(HttpResponse response, boolean encoding, String compareWith, String extension) throws IOException {
+    private String assertResponse(HttpResponse response, boolean encoding, String compareWith, String extension, String contentType) throws IOException {
         Assert.assertEquals(StatusCodes.OK, response.getStatusLine().getStatusCode());
         String body = HttpClientUtils.readResponse(response);
         Header[] headers = response.getHeaders(Headers.CONTENT_TYPE_STRING);
-        Assert.assertEquals("text/html", headers[0].getValue());
+        Assert.assertEquals(contentType, headers[0].getValue());
 
         if (encoding) {
             assert response.getEntity() instanceof DecompressingEntity; //no other nice way to be sure we get back gzipped content

core/src/test/java/io/undertow/server/handlers/file/data1.json

@@ -0,0 +1,21 @@
+{
+  "undertow": {
+    "title": "compressed resource",
+    "subtype": {
+      "method": "test json compressed resource",
+      "listInfo": {
+        "test": {
+          "json": "js",
+          "compressed": "c",
+          "resource": "this file",
+          "type": "data",
+          "def": {
+            "thisFile": "Test purposes",
+            "seeAlso": ["data2", "json"]
+          },
+          "See": "compression"
+        }
+      }
+    }
+  }
+}

core/src/test/java/io/undertow/server/handlers/file/data2.json

@@ -0,0 +1,21 @@
+{
+  "undertow": {
+    "title": "compressed resource",
+    "subtype": {
+      "method": "test json compressed resource",
+      "listInfo": {
+        "test": {
+          "json": "js",
+          "compressed": "c",
+          "resource": "this file",
+          "type": "data",
+          "def": {
+            "thisFile": "Test purposes",
+            "seeAlso": ["data1", "json"]
+          },
+          "See": "compression"
+        }
+      }
+    }
+  }
+}