Cloud API – PDF To JSON – Java – Convert PDF To JSON From Uploaded File

How to Convert PDF To JSON From Uploaded File in Java

Developers of any skill level or experience would find writing the code to convert PDF to JSON from uploaded file in Java is fast and easy when using Cloud API.

Not only that Cloud API streamlines the process of PDF to JSON Web API conversion in Java, it likewise provides a set of tools for various functions. This Rest API can easily implement data extraction, document manipulation, splitting, and merging PDFs, and a lot more. And with its built-in OCR and image recognition technology, it can also generate and read barcodes from images, scans, and PDFs.

By taking the code below, you can instantly use it in your applications without the need to write and test a code of your own. Just open your Java project, copy & paste the code then run your app! All you need for implementing PDF to JSON Web API is to use this basic programming language sample code for Java to get the job done.

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Main.java Code

package com.company;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import okhttp3.*;

import java.io.*;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Main
{
    // (!) If you are getting '(403) Forbidden' error please ensure you have set the correct API_KEY

    // The authentication key (API Key).
    // Get your own by registering at https://secure.bytescout.com/users/sign_up
    final static String API_KEY = "***********************************";

    // Source PDF file
    final static Path SourceFile = Paths.get(".\\sample.pdf");
    // Comma-separated list of page indices (or ranges) to process. Leave empty for all pages. Example: '0,2-5,7-'.
    final static String Pages = "";
    // PDF document password. Leave empty for unprotected documents.
    final static String Password = "";
    // Destination JSON file name
    final static Path DestinationFile = Paths.get(".\\result.json");


    public static void main(String[] args) throws IOException
    {
        // Create HTTP client instance
        OkHttpClient webClient = new OkHttpClient();

        // 1. RETRIEVE THE PRESIGNED URL TO UPLOAD THE FILE.
        // * If you already have a direct file URL, skip to the step 3.

        // Prepare URL for `Get Presigned URL` API call
        String query = String.format(
                "https://api.pdf.co/v1/file/upload/get-presigned-url?contenttype=application/octet-stream&name=%s",
                SourceFile.getFileName());

        // Prepare request
        Request request = new Request.Builder()
                .url(query)
                .addHeader("x-api-key", API_KEY) // (!) Set API Key
                .build();
        // Execute request
        Response response = webClient.newCall(request).execute();

        if (response.code() == 200)
        {
            // Parse JSON response
            JsonObject json = new JsonParser().parse(response.body().string()).getAsJsonObject();

            boolean error = json.get("error").getAsBoolean();
            if (!error)
            {
                // Get URL to use for the file upload
                String uploadUrl = json.get("presignedUrl").getAsString();
                // Get URL of uploaded file to use with later API calls
                String uploadedFileUrl = json.get("url").getAsString();

                // 2. UPLOAD THE FILE TO CLOUD.

                if (uploadFile(webClient, API_KEY, uploadUrl, SourceFile))
                {
                    // 3. CONVERT UPLOADED PDF FILE TO JSON

                    PdfToJson(webClient, API_KEY, DestinationFile, Password, Pages, uploadedFileUrl);
                }
            }
            else
            {
                // Display service reported error
                System.out.println(json.get("message").getAsString());
            }
        }
        else
        {
            // Display request error
            System.out.println(response.code() + " " + response.message());
        }
    }

    public static void PdfToJson(OkHttpClient webClient, String apiKey, Path destinationFile,
        String password, String pages, String uploadedFileUrl) throws IOException
    {
        // Prepare URL for `PDF To JSON` API call
        String query = String.format(
                "https://api.pdf.co/v1/pdf/convert/to/json?name=%s&password=%s&pages=%s&url=%s",
                destinationFile.getFileName(),
                password,
                pages,
                uploadedFileUrl);

        // Make correctly escaped (encoded) URL
        URL url = null;
        try
        {
            url = new URI(null, query, null).toURL();
        }
        catch (URISyntaxException e)
        {
            e.printStackTrace();
        }

        // Prepare request
        Request request = new Request.Builder()
                .url(url)
                .addHeader("x-api-key", apiKey) // (!) Set API Key
                .build();

        // Execute request
        Response response = webClient.newCall(request).execute();

        if (response.code() == 200)
        {
            // Parse JSON response
            JsonObject json = new JsonParser().parse(response.body().string()).getAsJsonObject();

            boolean error = json.get("error").getAsBoolean();
            if (!error)
            {
                // Get URL of generated JSON file
                String resultFileUrl = json.get("url").getAsString();

                // Download JSON file
                downloadFile(webClient, resultFileUrl, destinationFile.toFile());

                System.out.printf("Generated JSON file saved as \"%s\" file.", destinationFile.toString());
            }
            else
            {
                // Display service reported error
                System.out.println(json.get("message").getAsString());
            }
        }
        else
        {
            // Display request error
            System.out.println(response.code() + " " + response.message());
        }
    }

    public static boolean uploadFile(OkHttpClient webClient, String apiKey, String url, Path sourceFile) throws IOException
    {
        // Prepare request body
        RequestBody body = RequestBody.create(MediaType.parse("application/octet-stream"), sourceFile.toFile());

        // Prepare request
        Request request = new Request.Builder()
                .url(url)
                .addHeader("x-api-key", apiKey) // (!) Set API Key
                .addHeader("content-type", "application/octet-stream")
                .put(body)
                .build();

        // Execute request
        Response response = webClient.newCall(request).execute();

        return (response.code() == 200);
    }

    public static void downloadFile(OkHttpClient webClient, String url, File destinationFile) throws IOException
    {
        // Prepare request
        Request request = new Request.Builder()
                .url(url)
                .build();
        // Execute request
        Response response = webClient.newCall(request).execute();

        byte[] fileBytes = response.body().bytes();

        // Save downloaded bytes to file
        OutputStream output = new FileOutputStream(destinationFile);
        output.write(fileBytes);
        output.flush();
        output.close();

        response.close();
    }
}

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