Cloud - Create a PDF via Proxy using Java with XML Data

This example shows how to generate a PDF from a DOCX template via a proxy server using Java.  It calls the Docmosis REST API to merge the data with the template and stream the result back.

The sample code includes the instructions to get started. You will need a Free Trial and then plug your Docmosis Cloud access key into the code below, then run.

Note: This code sample is written to specifically work with DWS4.

import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Date;

/**
 * This sample code shows a render of the "samples/WelcomeTemplate.docx" template using XML format
 * instruction and data.
 *
 * There are several constants at the top of this file which you can modify to suit your test. You
 * need to set:
 *
 * ACCESS_KEY - this key is your unique access to the Docmosis services (keep it safe). You can see
 * your access key in your Account Settings in the Cloud area Docmosis web site.
 *
 * If you have troubles connecting, it is likely because you have a proxy server you need to
 * configure. See the PROXY_* settings below to enable it.
 * 
 * Copyright Docmosis 2019
 */
public class JavaProxyXMLExample 
{

	// Set your region here.
	// End-point in the USA
	private static final String DWS_RENDER_URL = "https://us1.dws4.docmosis.com/api/render";
	// End-point in the EU
	//private static final String DWS_RENDER_URL = "https://eu1.dws4.docmosis.com/api/render";
	// End-point in AUS
	//private static final String DWS_RENDER_URL = "https://au1.dws4.docmosis.com/api/render";

	// Set your access key here. This is visible in your cloud account in the Docmosis Web Site.
	// It is your key to accessing your service - keep it private and safe.
	private static final String ACCESS_KEY = "XXX";

	// The output format we want to produce (pdf, doc, docx, odt and more exist)
	private static final String OUTPUT_FORMAT = "pdf";

	// the name of the file we are going to write the document to
	private static final String OUTPUT_FILE = "myWelcome." + OUTPUT_FORMAT;
	
	// the name of the template in our cloud account we want to use
	private static final String TEMPLATE_NAME = "/samples/WelcomeTemplate.docx";

	// Proxy settings if needed to reach the internet
	private static final String PROXY_HOST = "";
	private static final String PROXY_PORT = "";
	private static final String PROXY_USER = "";
	private static final String PROXY_PASSWD = "";

	/*
	 * Get a connection to the Docmosis render service
	 */
	private static HttpURLConnection getConnection() throws MalformedURLException, IOException {

		HttpURLConnection conn = (HttpURLConnection) new URL(DWS_RENDER_URL).openConnection();

		// PROXY Setup
		// if you have a proxy, set the values here to make sure you can reach the internet
		if (!"".equals(PROXY_HOST)) {
			System.setProperty("proxyHost", PROXY_HOST);
			System.setProperty("proxyPort", PROXY_PORT);
			System.setProperty("proxySet", "true");

			if (!"".equals(PROXY_USER)) {
				// set username and password for PROXY access
				String auth = Base64Helper.toBase64((PROXY_USER + ":" + PROXY_PASSWD).getBytes());
				conn.setRequestProperty("Proxy-Authorization", auth);
			}

			System.out.println("connecting [via proxy] to " + DWS_RENDER_URL);
		} else {
			System.out.println("Connecting [directly] to " + DWS_RENDER_URL);
		}

		// set connection parameters
		conn.setRequestMethod("POST");
		conn.setUseCaches(false);
		conn.setDoOutput(true);
		conn.setDoInput(true);

		// this example uses JSON format
		conn.setRequestProperty("Content-Type", "application/xml; charset=utf-8");

		conn.connect();
		System.out.println("Connected");

		return conn;
	}

	/*
	 * Build the request in XML format. You can do it in JSON if you prefer (code not shown here).
	 */
	private static String buildRequest() {
		

		StringBuilder sb = new StringBuilder();

		// Start building the instruction
		sb.append("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
		sb.append("<render \n");
		sb.append("accessKey=\"").append(ACCESS_KEY).append("\" ");
		sb.append("templateName=\"").append(TEMPLATE_NAME).append("\" ");
		sb.append("outputName=\"").append(OUTPUT_FILE).append("\">\n");

		// now add the data specifically for this template
		sb.append("<data\n");
		sb.append(" title=\"Welcome to Docmosis in the Cloud\">\n");
		String[] messages = { "This cloud experience is better than I thought.",
				"The sun is shining", "Right, now back to work." };
		for (int i = 0; i < messages.length; i++) {
			sb.append("<messages msg=\"").append(messages[i]).append("\"/>\n");
		}
		sb.append("</data>\n");
		sb.append("</render>\n");

		return sb.toString();

	}

	/*
	 * Save the given Input stream to a file
	 */
	private static void saveToFile(InputStream content) throws IOException {
		byte[] buff = new byte[1000];
		int bytesRead = 0;

		File file = new File(OUTPUT_FILE);
		FileOutputStream fos = new FileOutputStream(file);
		try {
			while ((bytesRead = content.read(buff, 0, buff.length)) != -1) {
				fos.write(buff, 0, bytesRead);
			}
		} finally {
			fos.close();
		}

		System.out.println("Created file:" + file.getAbsolutePath());
	}

	/*
	 * Something went wrong in the call to the service, tell the user about it
	 */
	private static void processError(HttpURLConnection conn, int status)
			throws IOException {
		System.err.println("Our call failed: status = " + status);
		System.err.println("message:" + conn.getResponseMessage());
		BufferedReader errorReader = new BufferedReader(
				new InputStreamReader(conn.getErrorStream()));
		String msg;
		while ((msg = errorReader.readLine()) != null) {
			System.err.println(msg);
		}
		errorReader = null;

	}

	/*
	 * Run this example
	 */
	public static void main(String[] args) throws MalformedURLException,
			IOException {
		if ("XXX".equals(ACCESS_KEY)) {
			System.err.println("Please set your private ACCESS_KEY at the top of this file from your Docmosis cloud account.");
			System.exit(1);
		}

		HttpURLConnection conn = null;
		try {
			conn = getConnection();
		} catch (ConnectException e) {
			// can't make the connection
			System.err.println("Unable to connect to the docmosis cloud:" + e.getMessage());
			System.err.println("If you have a proxy, configure proxy settings at the top of this example.");
			System.exit(2);
		}

		try {
			String renderRequest = buildRequest();

			System.out.println("Sending request:" + renderRequest);

			// write data using UTF-8 encoding so that most character sets are
			// available
			OutputStreamWriter os = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
			os.write(renderRequest);
			os.flush();

			int status = conn.getResponseCode();

			if (status == 200) {
				// successful render,
				// save our document to a file
				saveToFile(conn.getInputStream());
			} else {
				// something went wrong - tell the user
				processError(conn, status);
			}

		} finally {
			conn.disconnect();
		}

	}

	/**
	 * A helper for dealing with Base64 encoding.  This is only needed if you are
	 * using a proxy to reach the internet and must authenticate with the proxy.
	 */
	private static class Base64Helper
	{
		private static final char[] B64_DIGIT = { 'A', 'B', 'C', 'D', 'E', 'F',
			'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
			'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
			'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's',
			't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
			'6', '7', '8', '9', '+', '-' };

		public static String toBase64(byte[] data) {
			int i = 0;
			int chunks = data.length / 3;
			StringBuilder sb = new StringBuilder(chunks * 4 + 2);
			for (int count = 0; count < chunks; count++, i += 3) {
				int buffer = ((data[i] & 0xFF) << 16) | ((data[i + 1] & 0xFF) << 8)
						| (data[i + 2] & 0xFF);
				sb.append(B64_DIGIT[(buffer & 0xFC0000) >> 18]);
				sb.append(B64_DIGIT[(buffer & 0x03F000) >> 12]);
				sb.append(B64_DIGIT[(buffer & 0x000FC0) >> 6]);
				sb.append(B64_DIGIT[(buffer & 0x00003F)]);
			}
			// padding
			int buffer;
			switch (data.length - i) {
			case 2:
				buffer = ((data[i] & 0xFF) << 16) | ((data[i + 1] & 0xFF) << 8);
				sb.append(B64_DIGIT[(buffer & 0xFC0000) >> 18]);
				sb.append(B64_DIGIT[(buffer & 0x03F000) >> 12]);
				sb.append(B64_DIGIT[(buffer & 0x000FC0) >> 6]);
				sb.append('=');
				break;
			case 1:
				buffer = ((data[i] & 0xFF) << 16);
				sb.append(B64_DIGIT[(buffer & 0xFC0000) >> 18]);
				sb.append(B64_DIGIT[(buffer & 0x03F000) >> 12]);
				sb.append("==");
				break;
			}
			return sb.toString();
		}
	}
}