The tus protocol enables resumable file uploads over HTTP, allowing uploads to be paused and resumed without re-uploading previous data. This is particularly useful for large files and unstable networks. Let's explore how to use the tus-java-client library to implement resumable uploads in Java.

Setting up tus-java-client

Add the dependency to your project:

<dependency>
  <groupId>io.tus.java.client</groupId>
  <artifactId>tus-java-client</artifactId>
  <version>0.5.0</version>
</dependency>

Basic usage

Here's a complete example showing how to use tus-java-client with best practices:

import io.tus.java.client.*;

import java.io.File;
import java.io.IOException;
import java.net.URL;

public class TusUploaderExample {
    public static void main(String[] args) {
        try {
            // Create and configure client
            TusClient client = new TusClient();
            client.setUploadCreationURL(new URL("https://tusd.tusdemo.net/files"));
            client.enableResuming(new TusURLMemoryStore());

            // Prepare file for upload
            File file = new File("path/to/your/file.ext");
            final TusUpload upload = new TusUpload(file);

            // Use TusExecutor for automatic retries
            TusExecutor executor = new TusExecutor() {
                @Override
                protected void makeAttempt() throws ProtocolException, IOException {
                    // Resume or create upload
                    TusUploader uploader = client.resumeOrCreateUpload(upload);

                    // Set chunk size (1KB in this example)
                    uploader.setChunkSize(1024);

                    // Upload with progress tracking
                    do {
                        long totalBytes = upload.getSize();
                        long bytesUploaded = uploader.getOffset();
                        double progress = (double) bytesUploaded / totalBytes * 100;
                        System.out.printf("Upload at %06.2f%%.\n", progress);
                    } while(uploader.uploadChunk() > -1);

                    uploader.finish();
                    System.out.println("Upload URL: " + uploader.getUploadURL());
                }
            };
            executor.makeAttempts();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Advanced features

  • Custom Server Support: For servers without Creation extension support:

    TusUploader uploader = client.beginOrResumeUploadFromURL(upload,
    new URL("https://tus.server.net/files/my_file"));

  • Proxy Support: Add a proxy to the client:

    client.setProxy(new Proxy(Proxy.Type.HTTP,
    new InetSocketAddress("proxy.example.com", 8080)));

  • Custom SSL: Extend TusClient to use your own SSLSocketFactory:

    @Override
public void prepareConnection(@NotNull HttpURLConnection connection) {
    super.prepareConnection(connection);
    if(connection instanceof HttpsURLConnection) {
        ((HttpsURLConnection) connection).setSSLSocketFactory(mySSLSocketFactory);
    }
}

Platform compatibility

The library works on both standard Java and Android platforms. For Android-specific features, check out tus-android-client.

For more details, visit the tus-java-client documentation and GitHub repository.