Add deferred-length TUS devdock proof

Author: kvz

example/build.gradle

@@ -24,6 +24,12 @@ tasks.register('api2DevdockTusCreationWithUpload', JavaExec) {
     workingDir = rootProject.projectDir
 }
 
+tasks.register('api2DevdockTusDeferredLengthUpload', JavaExec) {
+    classpath = sourceSets.main.runtimeClasspath
+    mainClass = 'io.tus.java.example.Api2DevdockTusDeferredLengthUpload'
+    workingDir = rootProject.projectDir
+}
+
 tasks.register('api2DevdockTusRetryOffsetRecovery', JavaExec) {
     classpath = sourceSets.main.runtimeClasspath
     mainClass = 'io.tus.java.example.Api2DevdockTusRetryOffsetRecovery'

example/src/main/java/io/tus/java/example/Api2DevdockTusDeferredLengthUpload.java

@@ -0,0 +1,90 @@
+package io.tus.java.example;
+
+import io.tus.java.client.ProtocolException;
+import io.tus.java.client.TusClient;
+import io.tus.java.client.TusUpload;
+import io.tus.java.client.TusUploader;
+import org.json.JSONObject;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.net.URL;
+
+public final class Api2DevdockTusDeferredLengthUpload {
+    /**
+     * Run the API2 devdock TUS deferred-length upload example.
+     *
+     * @param args ignored
+     */
+    public static void main(String[] args) {
+        try {
+            System.setProperty("http.strictPostRedirect", "true");
+
+            final JSONObject scenario = Api2DevdockScenario.loadScenario();
+            final JSONObject createResponse = Api2DevdockScenario.createResponse(scenario);
+            final String uploadUrl = uploadWithDeferredLength(scenario, createResponse);
+            Api2DevdockScenario.writeResult(new JSONObject().put("uploadUrl", uploadUrl));
+
+            System.out.println(
+                    "Java TUS SDK devdock scenario "
+                            + scenario.getString("scenarioId")
+                            + " uploaded with deferred length to "
+                            + uploadUrl
+            );
+        } catch (Exception e) {
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static String uploadWithDeferredLength(
+            JSONObject scenario,
+            JSONObject createResponse
+    ) throws IOException, ProtocolException {
+        final JSONObject uploadConfig = scenario.getJSONObject("upload");
+        final byte[] content = Api2DevdockScenario.scenarioBytes(uploadConfig);
+        final int chunkSize = Api2DevdockScenario.fixedChunkSizeBytes(uploadConfig);
+        if (!uploadConfig.getBoolean("uploadLengthDeferred")) {
+            throw new IllegalStateException(
+                    "deferred-length scenario must set uploadLengthDeferred"
+            );
+        }
+
+        final TusClient client = new TusClient();
+        client.setUploadCreationURL(
+                new URL(Api2DevdockScenario.tusUrl(uploadConfig, scenario, createResponse))
+        );
+
+        final TusUpload upload = new TusUpload();
+        upload.setInputStream(new ByteArrayInputStream(content));
+        upload.setSize(content.length);
+        upload.setFingerprint(scenario.getString("scenarioId") + "-java-deferred-length");
+        upload.setMetadata(
+                Api2DevdockScenario.uploadMetadata(uploadConfig, scenario, createResponse)
+        );
+        upload.setUploadLengthDeferred(true);
+
+        final TusUploader uploader = client.createUpload(upload);
+        uploader.setChunkSize(chunkSize);
+        int uploadedChunkSize;
+        do {
+            uploadedChunkSize = uploader.uploadChunk();
+        } while (uploadedChunkSize > -1);
+        uploader.finish();
+
+        if (uploader.getOffset() != content.length) {
+            throw new IllegalStateException(
+                    "remote offset " + uploader.getOffset() + ", expected " + content.length
+            );
+        }
+        if (uploader.getUploadURL() == null) {
+            throw new IllegalStateException("deferred-length upload did not return a URL");
+        }
+
+        return uploader.getUploadURL().toString();
+    }
+
+    private Api2DevdockTusDeferredLengthUpload() {
+        throw new IllegalStateException("Utility class");
+    }
+}