Upload a file to MifosX using https://demo.openmf.org/api-docs/apiLive.htm#documents_create API

FileUpload.java

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.URL;
import java.net.URLConnection;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.util.ArrayList;
import java.util.List;

import javax.net.ssl.HttpsURLConnection;

public class FileUpload {

	private final String boundary;
	private static final String LINE_FEED = "\r\n";
	private final HttpsURLConnection httpConn;
	private final String charset;
	private final OutputStream outputStream;
	private final 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
	 * @throws CertificateException
	 * @throws NoSuchAlgorithmException
	 * @throws KeyManagementException
	 * @throws KeyStoreException
	 */
	public FileUpload(String requestURL, String charset) throws IOException,
			NoSuchAlgorithmException, CertificateException,
			KeyManagementException, KeyStoreException {
		this.charset = charset;

		// creates a unique boundary based on time stamp
		boundary = "----WebKitFormBoundarydPlPWmVVYWkNeTAf";
		/**
		 * KeyStore keyStore; keyStore =
		 * KeyStore.getInstance(KeyStore.getDefaultType());
		 * 
		 * keyStore.load( new FileInputStream(
		 * "W:/mifos/mifosx/mifosng-provider/src/main/resources/keystore.jks"),
		 * null); TrustManagerFactory tmf = TrustManagerFactory
		 * .getInstance(TrustManagerFactory.getDefaultAlgorithm());
		 * tmf.init(keyStore); SSLContext ctx = SSLContext.getInstance("TLS");
		 * ctx.init(null, tmf.getTrustManagers(), null); SSLSocketFactory
		 * sslFactory = ctx.getSocketFactory();
		 **/

		URL url = new URL(requestURL);
		httpConn = (HttpsURLConnection) url.openConnection();
		/** httpConn.setSSLSocketFactory(sslFactory); **/
		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", "CodeJava Agent");
		httpConn.setRequestProperty("Test", "Bonjour");
		httpConn.setRequestProperty("Authorization",
				"Basic bWlmb3M6cGFzc3dvcmQ=");
		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();
		String contentType = URLConnection.guessContentTypeFromName(fileName);
		System.out.println(contentType);

		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[4096];
		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 == HttpsURLConnection.HTTP_OK || status == 401) {
			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;
	}

	public static void main(String[] args) throws KeyManagementException,
			NoSuchAlgorithmException, CertificateException, KeyStoreException {
		String charset = "UTF-8";
		File uploadFile1 = new File(
				"W:/mifos/workspace/Datta/src/FileUpload.java");

		String requestURL = "https://demo.openmf.org/mifosng-provider/api/v1/clients/43/documents?tenantIdentifier=default";

		try {
			FileUpload fileUpload = new FileUpload(requestURL, charset);

			fileUpload.addHeaderField("User-Agent", "CodeJava");
			fileUpload.addHeaderField("Test-Header", "Header-Value");
			fileUpload.addHeaderField("Authorization",
					"Basic bWlmb3M6cGFzc3dvcmQ=");

			fileUpload.addFormField("name",
					"A file to Illustrate that the mifosx api works");
			fileUpload.addFormField("description", "Cool Pictures");

			fileUpload.addFilePart("file", uploadFile1);

			List<String> response = fileUpload.finish();

			System.out.println("SERVER REPLIED:");

			for (String line : response) {
				System.out.println(line);
			}
		} catch (IOException ex) {
			System.err.println(ex);
		}
	}
}