Java SDK

Official Java SDK for TruthMark invisible watermarking.

Installation

Maven
<dependency>
    <groupId>com.truthmark</groupId>
    <artifactId>truthmark-sdk</artifactId>
    <version>1.0.0</version>
</dependency>
Gradle
implementation 'com.truthmark:truthmark-sdk:1.0.0'

Quick Example

import com.truthmark.sdk.TruthMarkClient;
import com.truthmark.sdk.TruthMarkClient.EncodeResult;
import com.truthmark.sdk.TruthMarkClient.DecodeResult;

public class Example {
    public static void main(String[] args) {
        TruthMarkClient client = new TruthMarkClient.Builder()
            .apiKey("tm_live_your_key")
            .baseUrl("https://truthmark-api.onrender.com")
            .build();

        try {
            // Encode
            EncodeResult result = client.encode("image.png", "Copyright 2025");
            System.out.println("Download: " + result.getDownloadUrl());
            System.out.printf("PSNR: %.1f dB%n", result.getMetadata().getPsnr());

            // Decode
            DecodeResult decoded = client.decode("watermarked.png");
            if (decoded.isFound()) {
                System.out.println("Message: " + decoded.getMessage());
                System.out.printf("Confidence: %.1f%%%n", decoded.getConfidence() * 100);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

API Reference

TruthMarkClient.Builder

Configure and create a client instance.

  • .apiKey(String) — Your TruthMark API key
  • .baseUrl(String) — API base URL
  • .timeout(int) — Request timeout in ms
  • .build() — Create the client

encode(String imagePath, String message)

Embed an invisible watermark. Returns EncodeResult.

decode(String imagePath)

Extract watermark. Returns DecodeResult.

Error Handling

import com.truthmark.sdk.TruthMarkException;

try {
    EncodeResult result = client.encode("image.png", "message");
} catch (TruthMarkException e) {
    switch (e.getStatusCode()) {
        case 401 -> System.err.println("Invalid API key");
        case 429 -> System.err.println("Rate limited. Retry after: " + e.getRetryAfter());
        case 413 -> System.err.println("Image too large (max 20MB)");
        default  -> System.err.println("Error: " + e.getMessage());
    }
}

Advanced Examples

Spring Boot Service

@Service
public class WatermarkService {
    private final TruthMarkClient client;

    public WatermarkService(@Value("${truthmark.api-key}") String apiKey) {
        this.client = new TruthMarkClient.Builder()
            .apiKey(apiKey)
            .build();
    }

    public EncodeResult watermark(MultipartFile file, String message) throws Exception {
        Path temp = Files.createTempFile("upload", ".png");
        file.transferTo(temp);
        try {
            return client.encode(temp.toString(), message);
        } finally {
            Files.deleteIfExists(temp);
        }
    }
}

Batch Processing with Streams

Path dir = Path.of("./images");
List<EncodeResult> results = Files.list(dir)
    .filter(p -> p.toString().matches(".*\\.(png|jpg|jpeg)$"))
    .parallel()
    .map(p -> {
        try {
            return client.encode(p.toString(), "© 2025 My Company");
        } catch (Exception e) {
            System.err.println("Failed: " + p + " - " + e.getMessage());
            return null;
        }
    })
    .filter(Objects::nonNull)
    .collect(Collectors.toList());

System.out.printf("Watermarked %d images%n", results.size());

Best Practices

Reuse client instances

Create one TruthMarkClient per application — it's thread-safe.

Use environment variables

Store API keys in application.properties or env vars, never hardcode.

Don't ignore exceptions

Always handle TruthMarkException — check status codes for retryable errors.

Need Help?

Check out the API reference or reach out to support.

API ReferenceContact Support