---
title: "Java"
description: "Generate images with the Imejis.io API in Java using the built-in HttpClient. A tested example that POSTs dynamic field overrides to a design and saves the rendered image."
url: "https://www.imejis.io/apis/java"
published: "2026-07-25"
---

# Java

## Java

Generate an image from a template with a single POST request, using the `java.net.http.HttpClient` built into Java 11 and later. Imejis returns the finished image directly, so there are no webhooks and nothing to poll.

Set two environment variables first: `IMEJIS_API_KEY` (from your dashboard) and `IMEJIS_DESIGN_ID` (any design's ID). Then send the fields you want to change as `component.property` pairs, for example `headline.text`.

```java showLineNumbers title="Java (HttpClient)"
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.io.FileOutputStream;

public class Main {
    public static void main(String[] args) throws Exception {
        String designId = System.getenv("IMEJIS_DESIGN_ID");
        String apiKey = System.getenv("IMEJIS_API_KEY");
        String json = "{\"headline.text\":\"Hello from Java\"}";

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create("https://render.imejis.io/v1/" + designId))
            .header("dma-api-key", apiKey)
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(json))
            .build();

        HttpResponse<byte[]> response =
            client.send(request, HttpResponse.BodyHandlers.ofByteArray());
        try (FileOutputStream out = new FileOutputStream("output.jpg")) {
            out.write(response.body());
        }
        System.out.println("status " + response.statusCode() + " bytes " + response.body().length);
    }
}
```

**Override any field.** Each dynamic component exposes keys like `headline.text`, `title.color`, or `image.image`. Send only the ones you want to change. You can find a design's overridable fields in its Share / API panel.

The response is the raw image (`image/jpeg` by default). Save it to disk, stream it, or return it straight from your own endpoint.