How to send a HTTP request to servlet in java application

Question

I'm new in Java. I need to send a HTTP request with parameters to servlet in a java aplication. Here is my code. It can be compiled but always threw an exceptions when I ran it. Can anyone help?
package coreservlets;
import java.io.*;
import java.net.*;
public class PostHTTP
     public static void main(String args[])
          throws IOException, UnknownHostException {
          try
          // URL and servlet
               URL myURL = new URL("http://pc076/servlet/coreservlets.OffHold");
               URLConnection c = myURL.openConnection();
               c.setUseCaches(false);
               c.setDoOutput(true);
               ByteArrayOutputStream byteStream = new ByteArrayOutputStream(512);
               PrintWriter out = new PrintWriter(byteStream, true);
//parameters
               String postData = "REASON_CODE=3B&RSPCODE=JSmith&CASENUM=NA795401&REPLY=123&SOURCE=XYZ&REPLYLINK=http://pc076/servlet/coreservlets.ShowParameters";
               out.print(postData);
               out.flush();
               String lengthString = String.valueOf(byteStream.size());
               c.setRequestProperty("Content-Length", lengthString);
               c.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
               byteStream.writeTo(c.getOutputStream());
               BufferedReader in =     new BufferedReader(new InputStreamReader
                                             (c.getInputStream()));
               String line;
               //String linefeed = "\n";
               //resultsArea.setText("");
               while((line = in.readLine()) != null) {
                    System.out.println(line);
                    //resultsArea.append(linefeed);
          catch(IOException ioe) {
          // Print debug info in Java Console
          System.out.println("IOException: " + ioe);

Answer 1

here are some updates to your code I haven't tested it running
post again if you still have trouble
URL myURL = new URL("http://pc076/servlet/coreservlets.OffHold");
HttpURLConnection c = (HttpURLConnection)myURL.openConnection();
c.setDoInput(true);
c.setDoOutput(true);
ByteArrayOutputStream byteStream = new ByteArrayOutputStream(512);
String lengthString = String.valueOf(byteStream.size());
c.setRequestProperty("Content-Length", lengthString);
c.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
PrintWriter out = new PrintWriter(byteStream, true);
//parameters
String postData = "REASON_CODE=3B&RSPCODE=JSmith&CASENUM=NA795401&REPLY=123&SOURCE=XYZ&REPLYLINK=http://pc076/servlet/coreservlets.ShowParameters";
out.print(postData);
out.flush();
byteStream.writeTo(c.getOutputStream());
// connect
c.connect();
BufferedReader in = new BufferedReader(new InputStreamReader
(c.getInputStream()));
String line;
while((line = in.readLine()) != null)
    System.out.println(line);