Attempt creation if original upload can not be found anymore

Fixes #3

Author: Acconut

src/main/java/io/tus/java/client/TusClient.java

@@ -229,6 +229,15 @@ public TusUploader resumeOrCreateUpload(@NotNull TusUpload upload) throws Protoc
             return createUpload(upload);
         } catch(ResumingNotEnabledException e) {
             return createUpload(upload);
+        } catch(ProtocolException e) {
+            // If the attempt to resume returned a 404 Not Found, we immediately try to create a new
+            // one since TusExectuor would not retry this operation.
+            HttpURLConnection connection = e.getCausingConnection();
+            if(connection != null && connection.getResponseCode() == 404) {
+                return createUpload(upload);
+            }
+
+            throw e;
         }
     }
 

src/test/java/io/tus/java/client/TestTusClient.java

@@ -169,6 +169,41 @@ public void testResumeOrCreateUpload() throws IOException, ProtocolException {
         assertEquals(uploader.getUploadURL(), new URL(mockServerURL + "/foo"));
     }
 
+    @Test
+    public void testResumeOrCreateUploadNotFound() throws IOException, ProtocolException {
+        mockServer.when(new HttpRequest()
+                .withMethod("HEAD")
+                .withPath("/files/not_found")
+                .withHeader("Tus-Resumable", TusClient.TUS_VERSION))
+                .respond(new HttpResponse()
+                        .withStatusCode(404));
+
+        mockServer.when(new HttpRequest()
+                .withMethod("POST")
+                .withPath("/files")
+                .withHeader("Tus-Resumable", TusClient.TUS_VERSION)
+                .withHeader("Upload-Length", "10"))
+                .respond(new HttpResponse()
+                        .withStatusCode(201)
+                        .withHeader("Tus-Resumable", TusClient.TUS_VERSION)
+                        .withHeader("Location", mockServerURL + "/foo"));
+
+        TusClient client = new TusClient();
+        client.setUploadCreationURL(mockServerURL);
+
+        TusURLStore store = new TusURLMemoryStore();
+        store.set("fingerprint", new URL(mockServerURL + "/not_found"));
+        client.enableResuming(store);
+
+        TusUpload upload = new TusUpload();
+        upload.setSize(10);
+        upload.setInputStream(new ByteArrayInputStream(new byte[10]));
+        upload.setFingerprint("fingerprint");
+        TusUploader uploader = client.resumeOrCreateUpload(upload);
+
+        assertEquals(uploader.getUploadURL(), new URL(mockServerURL + "/foo"));
+    }
+
     @Test
     public void testPrepareConnection() throws IOException {
         HttpURLConnection connection = (HttpURLConnection) mockServerURL.openConnection();