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 MyMultipartUtility {    private final String boundary;    private static final String LINE_FEED = "\r\n";    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 MyMultipartUtility(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", "CodeJava Agent");        httpConn.setRequestProperty("Test", "Bonjour");        httpConn.setRequestProperty("Cookie", "JSESSIONID=19428F62C2FC9A3B96275AF0D9D3ED93");        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      * @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[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
    
      finish() throws IOException {        List
     
       response = new ArrayList
      
       ();         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;    }}
      
     
    

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 MyMultipartFileUploader {     public static void main(String[] args) {        String charset = "UTF-8";        File uploadFile1 = new File("TESTFILE");        String requestURL = "http://localhost:8080/TEST";         try {            MyMultipartUtility multipart = new MyMultipartUtility(requestURL, charset);                         multipart.addHeaderField("User-Agent", "CodeJava");            multipart.addHeaderField("Test-Header", "Header-Value");                         multipart.addFormField("env", "DEV");                         multipart.addFilePart("FILENAME", uploadFile1);             List
    
      response = multipart.finish();                         System.out.println("SERVER REPLIED:");                         for (String line : response) {                System.out.println(line);            }        } catch (IOException ex) {            System.err.println(ex);        }    }}