In this article, Jean-Michel gives a code example to upload attachments to Convertigo.
If you need to upload programmatically files to Convertigo server, this piece of code could be very useful.
Pre-requisites
1 – Setup a Convertigo Server running a project "UploadFileDemo" with a sequence expecting a file upload.
2 – Create an empty java project in your favorite development environment.
3 – Download the java example files from these links (MultiPartFileUploader.java and MultipartUtility.java).
4 – Add them to your blank project.
5 – Adapt MultiPartFileUploader.java to your environment by setting the path to the file repository, Convertigo Server url etc…
6 – Test
MultipartFileUploader : usage of the MultipartUtility class
package com.convertigo.networking; import java.io.File; import java.io.IOException; import java.util.List; /** *This program demonstrates a usage of the MultipartUtility class. * * @author www.codejava.net * */ public class MultipartFileUploader { public static void main(String[] args) { String charset = "UTF-8"; File uploadFile2 = new File("<...pathtofile...>/tgv_high-spped_train_france.jpg"); File uploadFile1 = new File("<...pathtofile...>/regional_train_in_italy.jpg"); String requestURL = "http://C8oServer:28080/convertigo/projects/UploadFileDemo/.xml"; try { MultipartUtility multipart = new MultipartUtility(requestURL, charset); multipart.addHeaderField("User-Agent", "Convertigo"); /** * __sequence contains the name of the called sequence * within the specified project (in the requestURL) */ multipart.addFormField("__sequence", "uploadFile"); /** * uploadFilename is the name of the sequence * input variable in the called project * * the value is the name that will be given to the file */ multipart.addFormField("uploadFilename", uploadFile1.getName()); // not needed but helpful in logs multipart.addFilePart("uploadFilename", uploadFile1); // multipart.addFilePart("uploadFilename", uploadFile2); List<String> response = multipart.finish(); System.out.println("SERVER REPLIED:"); for (String line : response) { System.out.println(line); } } catch (IOException ex) { System.err.println(ex); } } }
MultipartUtility : The upload utility itself (used as a library)
package com.convertigo.networking; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLConnection; import java.util.ArrayList; import java.util.List; /** * This utility class provides an abstraction layer for sending multipart HTTP * POST requests to a web server. * * @author www.codejava.net * */ public class MultipartUtility { private static final int CHUNKSIZE = 4096; private static final String LINE_FEED = "\r\n"; private final String boundary; private HttpURLConnection httpConn; private String charset; private OutputStream outputStream; private PrintWriter writer; /** * This constructor initializes a new HTTP POST request with content type is * set to multipart/form-data * * @param requestURL * @param charset * @throws IOException */ public MultipartUtility(String requestURL, String charset) throws IOException { this.charset = charset; // creates a unique boundary based on time stamp boundary = "===" + System.currentTimeMillis() + "==="; URL url = new URL(requestURL); httpConn = (HttpURLConnection) url.openConnection(); httpConn.setUseCaches(false); httpConn.setDoOutput(true); // indicates POST method httpConn.setDoInput(true); httpConn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary); httpConn.setRequestProperty("User-Agent", "Convertigo Agent"); outputStream = httpConn.getOutputStream(); writer = new PrintWriter(new OutputStreamWriter(outputStream, charset), true); } /** * Adds a form field to the request * * @param name * field name * @param value * field value */ public void addFormField(String name, String value) { writer.append("--" + boundary).append(LINE_FEED); writer.append("Content-Disposition: form-data; name=\"" + name + "\"").append(LINE_FEED); writer.append("Content-Type: text/plain; charset=" + charset).append(LINE_FEED); writer.append(LINE_FEED); writer.append(value).append(LINE_FEED); writer.flush(); } /** * Adds a upload file section to the request * * @param fieldName * name attribute in <input type="file" name="..." /> * @param uploadFile * a File to be uploaded * @throws IOException */ public void addFilePart(String fieldName, File uploadFile) throws IOException { String fileName = uploadFile.getName(); writer.append("--" + boundary).append(LINE_FEED); writer.append("Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + fileName + "\"").append(LINE_FEED); writer.append("Content-Type: " + URLConnection.guessContentTypeFromName(fileName)).append(LINE_FEED); writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED); writer.append(LINE_FEED); writer.flush(); FileInputStream inputStream = new FileInputStream(uploadFile); byte[] buffer = new byte[CHUNKSIZE]; int bytesRead = -1; while ((bytesRead = inputStream.read(buffer)) != -1) { outputStream.write(buffer, 0, bytesRead); } outputStream.flush(); inputStream.close(); writer.append(LINE_FEED); writer.flush(); } /** * Adds a header field to the request. * * @param name * - name of the header field * @param value * - value of the header field */ public void addHeaderField(String name, String value) { writer.append(name + ": " + value).append(LINE_FEED); writer.flush(); } /** * Completes the request and receives response from the server. * * @return a list of Strings as response in case the server returned status * OK, otherwise an exception is thrown. * @throws IOException */ public List<String> finish() throws IOException { List<String> response = new ArrayList<String>(); writer.append(LINE_FEED).flush(); writer.append("--" + boundary + "--").append(LINE_FEED); writer.close(); // checks server's status code first int status = httpConn.getResponseCode(); if (status == HttpURLConnection.HTTP_OK) { BufferedReader reader = new BufferedReader(new InputStreamReader(httpConn.getInputStream())); String line = null; while ((line = reader.readLine()) != null) { response.add(line); } reader.close(); httpConn.disconnect(); } else { throw new IOException("Server returned non-OK status: " + status); } return response; } }