Fill a PDF Form using PDF.co Web API in Java

18 Minutes Read

This tutorial and the sample source code explain filling a PDF form using the filling functionality from PDF.co Web API using Java programming language for Java developers. The users can utilize PDF Form Filler API to fill their respective PDF documents with their data interactively.

IN THIS TUTORIAL

Features of PDF Form Filler Web API

Endpoint Parameters

PDF Filler Source Code in Java

Source Code Snippet

Step-by-Step Guide to Use Form Filler API

Filled 4506-T Form Output

Features of PDF Form Filler Web API

Moreover, the PDF.co Web API possesses beneficial tools to fill a form by benefiting from easy field-name mapping, using e-signature support, and using an on-premise API server. The PDF.co Form Filler API works extremely fast to fill out forms rather than manually handling them. The data to be filed can be from different sources such as spreadsheets, CRM’s, and user input.

A PDF form can have various fields such as text fields, checkboxes, radio buttons, and combo boxes. There is also an option to embed e-signature and other important image objects which the document needs. A demo explaining all of these features in detail is below to help users understand it more easily.

Another critical thing to consider here is that the PDF.co Web API provides high security. This API transmits the user’s documents and data files via encrypted connections. Users can learn more about the PDF.co API security here.

Endpoint Parameters

Following are the parameters of the PDF Form Filler API.

PDF Filler Source Code in Java

The following source code shows users how to fill a sample PDF form using the PDF.co Form Filler API. The sample code in Java shows how to fill a sample form like IRS Form 4506. This form mainly consists of some text fields and checkboxes along with the signature in the form. The users can use the Get PDF Info tool to get the field names in an interactive PDF. Users can access it in the Helpers Tools menu in their respective PDF.co accounts. A direct link to the feature is here.

Users can upload their PDF documents to get critical information about their respective documents, such as the text fields, edit boxes, checkboxes, page numbers, and the location of every field to help the filling process efficiently.

The code contains IRS Form 4506 as an example here. The user needs to provide an API key generated by the PDF.co login and the pdf file URL in the API request for the API to work. Moreover, the pdf.co API returns the resulting or edited file URL from which the user can download the file and keep it on his local storage. The result.pdf file contains the filled document after execution of the code and fills the document with required important information.

Source Code Snippet

Here is an example URL code snippet.

package com.company;

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

import com.google.gson.*;
import okhttp3.*;
import java.io.IOException;
import java.net.http.*;
import java.net.URI;
public class Main {
// The authentication key (API Key).
// Get your own by registering at https://app.pdf.co
final static String API_KEY = "********************";

// Direct URL of source PDF file.
final static String SourceFileUrl = "https://www.irs.gov/pub/irs-pdf/f4506t.pdf";
// PDF document password. Leave empty for unprotected documents.
final static String Password = "";

// Destination PDF file name
final static Path ResultFile = Paths.get(".result.pdf");

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

// Prepare URL for `PDF Edit` API call
String query = "https://api.pdf.co/v1/pdf/edit/add";

// Prepare form filling data
String fields = "[n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_1[0]",n" +
"            "pages": "0",n" +
"            "text": "John A."n" +
"        },        n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_2[0]",n" +
"            "pages": "0",n" +
"            "text": "Doe"n" +
"        },        n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_3[0]",n" +
"            "pages": "0",n" +
"            "text": "XYZ"n" +
"        },n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_4[0]",n" +
"            "pages": "0",n" +
"            "text": "1234567"n" +
"        },n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_5[0]",n" +
"            "pages": "0",n" +
"            "text": "Las Vegas, Nevada"n" +
"        },n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_6[0]",n" +
"            "pages": "0",n" +
"            "text": "ABCDE"n" +
"        },n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].customer_file_number[0]",n" +
"            "pages": "0",n" +
"            "text": "987654321"n" +
"        },     n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].c1_1[1]",n" +
"            "pages": "0",n" +
"            "text": "True"n" +
"        },     n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_24[0]",n" +
"            "pages": "0",n" +
"            "text": "05"n" +
"        },     n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_25[0]",n" +
"            "pages": "0",n" +
"            "text": "01"n" +
"        },     n" +
"        {n" +
"            "fieldName": "topmostSubform[0].Page1[0].f1_26[0]",n" +
"            "pages": "0",n" +
"            "text": "20"n" +
"        }     n" +
"    ]";


// Asynchronous Job
String async = "false";

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


// Create JSON payload
String jsonPayload = String.format("{n" +
"    "url": "%s",n" +
"    "async": %s,n" +
"    "encrypt": false,n" +
"    "name": "f1040-filled",n" +
"    "fields": %s"+
"}", SourceFileUrl, async, fields);

// Prepare request body
RequestBody body = RequestBody.create(MediaType.parse("application/json"), jsonPayload);
// Prepare request
Request request = new Request.Builder()
.url(url)
.addHeader("x-api-key", API_KEY) // (!) Set API Key
.addHeader("Content-Type", "application/json")
.post(body)
.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 output file
String resultFileUrl = json.get("url").getAsString();
System.out.println(resultFileUrl);

// Download the image file
downloadFile(webClient, resultFileUrl, ResultFile);
System.out.printf("Generated file saved to "%s" file.", ResultFile.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 void downloadFile(OkHttpClient webClient, String url, Path 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.toFile());
output.write(fileBytes);
output.flush();
output.close();
response.close();
}
}Code javacodeco