OcrWithExtractText.java

import io.github.cdimascio.dotenv.Dotenv;
import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;
import okhttp3.*;
import org.json.JSONObject;

/* In this sample, we will show how to convert a scanned document into a PDF with
 * searchable and extractable text using Optical Character Recognition (OCR), and then
 * extract that text from the newly created document.
 *
 * First, we will upload a scanned PDF to the /pdf-with-ocr-text route and capture the
 * output ID. Then, we will send the output ID to the /extracted-text route, which will
 * return the newly added text.
 */

public class OcrWithExtractText {

  // By default, we use the US-based API service. This is the primary endpoint for global use.
  private static final String API_URL = "https://api.pdfrest.com";

  // For GDPR compliance and enhanced performance for European users, you can switch to the EU-based
  // service by commenting out the URL above and uncommenting the URL below.
  // For more information visit https://pdfrest.com/pricing#how-do-eu-gdpr-api-calls-work
  // private static final String API_URL = "https://eu-api.pdfrest.com";

  // Specify the path to your PDF file here, or as the first argument when running the program.
  private static final String DEFAULT_PDF_FILE_PATH = "/path/to/file.pdf";

  // Specify your API key here, or in the environment variable PDFREST_API_KEY.
  // You can also put the environment variable in a .env file.
  private static final String DEFAULT_API_KEY = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";

  public static void main(String[] args) {
    File pdfFile;
    if (args.length > 0) {
      pdfFile = new File(args[0]);
    } else {
      pdfFile = new File(DEFAULT_PDF_FILE_PATH);
    }

    final Dotenv dotenv = Dotenv.configure().ignoreIfMalformed().ignoreIfMissing().load();

    final RequestBody pdfFileRequestBody =
        RequestBody.create(pdfFile, MediaType.parse("application/pdf"));
    RequestBody ocrRequestBody =
        new MultipartBody.Builder()
            .setType(MultipartBody.FORM)
            .addFormDataPart("file", pdfFile.getName(), pdfFileRequestBody)
            .addFormDataPart("output", "example_pdf-with-ocr-text_out")
            .build();
    Request ocrRequest =
        new Request.Builder()
            .header("Api-Key", dotenv.get("PDFREST_API_KEY", DEFAULT_API_KEY))
            .url(API_URL + "/pdf-with-ocr-text")
            .post(ocrRequestBody)
            .build();
    try {
      OkHttpClient ocrClient =
          new OkHttpClient().newBuilder().readTimeout(60, TimeUnit.SECONDS).build();

      Response ocrResponse = ocrClient.newCall(ocrRequest).execute();

      System.out.println("Response status code: " + ocrResponse.code());
      if (ocrResponse.body() != null) {
        String ocrResponseString = ocrResponse.body().string();

        JSONObject ocrJSON = new JSONObject(ocrResponseString);
        if (ocrJSON.has("error")) {
          System.out.println("Error during OCR call: " + ocrResponseString);
          return;
        }

        String ocrPDFID = ocrJSON.get("outputId").toString();
        System.out.println("Got the output ID: " + ocrPDFID);

        RequestBody extractRequestBody =
            new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("id", ocrPDFID)
                .build();
        Request extractRequest =
            new Request.Builder()
                .header("Api-Key", dotenv.get("PDFREST_API_KEY", DEFAULT_API_KEY))
                .url(API_URL + "/extracted-text")
                .post(extractRequestBody)
                .build();
        try {
          OkHttpClient extractClient =
              new OkHttpClient().newBuilder().readTimeout(60, TimeUnit.SECONDS).build();

          Response extractResponse = extractClient.newCall(extractRequest).execute();

          System.out.println("Response status code: " + extractResponse.code());
          if (extractResponse.body() != null) {
            String extractResponseString = extractResponse.body().string();

            JSONObject extractJSON = new JSONObject(extractResponseString);
            if (extractJSON.has("error")) {
              System.out.println("Error during text extraction call: " + extractResponseString);
              return;
            }

            System.out.println(extractJSON.getString("fullText"));
          }
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }
    } catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
}