Here's a simpler example of the code that won't work.
Again, here the applet seems not to be connecting the servlet. However, I verified the servlet worked from the browser before changing its code. That is, the port assignment is OK.
Also, the getInputStream() line is the last line that executes in the Applet.
=============================
Applet code:
=============================
package testapplettoservlet;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.servlet.http.*;
import java.io.*;
import java.net.*; // for URL class
public class Applet1 extends Applet implements Serializable
{
private boolean isStandalone = false;
private JButton cmdSend = new JButton();
private JLabel lblStatus = new JLabel();
//Get a parameter value
public String getParameter(String key, String def)
{
return isStandalone ? System.getProperty(key, def) :
(getParameter(key) != null ? getParameter(key) : def);
}
//Construct the applet
public Applet1()
{
}
//Initialize the applet
public void init()
{
try
{
jbInit();
}
catch(Exception e)
{
e.printStackTrace();
}
}
//Component initialization
private void jbInit() throws Exception
{
cmdSend.setBounds(new Rectangle(155, 37, 67, 27));
cmdSend.setForeground(Color.blue);
cmdSend.setText("Send!");
cmdSend.addActionListener(new Applet1_cmdSend_actionAdapter(this));
lblStatus.setText("Waiting....");
lblStatus.setBounds(new Rectangle(43, 88, 292, 17));
this.setLayout(null);
this.add(lblStatus, null);
this.add(cmdSend, null);
}
//Get Applet information
public String getAppletInfo()
{
return "Applet Information";
}
//Get parameter info
public String[][] getParameterInfo()
{
return null;
}
void cmdSend_actionPerformed(ActionEvent e)
{
ObjectOutputStream outputToServlet;
try
{
// finally, create the URL.
URL dataURL = new URL("http://localhost:8081/servlet/testapplettoservlet.Servlet1");
// URL dataURL = new URL(protocol, host, port, urlSuffix);
URLConnection connection = dataURL.openConnection();
if (connection == null)
{
JOptionPane.showMessageDialog(null, "No URL connection established!");
return;
}
// inform the connection that we will send output and accept input
connection.setDoInput(true);
connection.setDoOutput(true);
// Don't use a cached version of URL connection.
connection.setUseCaches (false);
connection.setDefaultUseCaches (false);
String stringToSend = "Hello from Applet!";
// Specify the content type that we will send binary data
// not necessary when sending serialized objects as below.
connection.setRequestProperty(
"Content-Type", "application/x-java-serialized-object");
// send the Pilates ArrayList object to the servlet using serialization
outputToServlet = new ObjectOutputStream(
connection.getOutputStream());
// serialize the object
if (stringToSend != null)
{
outputToServlet.writeObject(stringToSend);
}
else
{
JOptionPane.showMessageDialog(null, "No Message to Send.");
}
ObjectInputStream in = new ObjectInputStream(connection.getInputStream());
// try to read servlet's response
String line;
this.lblStatus.setText("");
line = in.readLine();
lblStatus.setText(line);
outputToServlet.flush();
outputToServlet.close();
}
catch (Exception mfe)
{
JOptionPane.showMessageDialog(null, mfe.getMessage());
}
}
}
class Applet1_cmdSend_actionAdapter implements java.awt.event.ActionListener
{
private Applet1 adaptee;
Applet1_cmdSend_actionAdapter(Applet1 adaptee)
{
this.adaptee = adaptee;
}
public void actionPerformed(ActionEvent e)
{
adaptee.cmdSend_actionPerformed(e);
}
}
============================================
Servlet code:
============================================
package testapplettoservlet;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
public class Servlet1 extends HttpServlet
{
static final private String CONTENT_TYPE =
"application/x-java-serialized-object";
//Initialize global variables
public void init() throws ServletException
{
}
//Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
/*
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>Servlet1</title></head>");
out.println("<body>");
out.println("<p>The servlet has received a GET. This is the reply.</p>");
out.println("</body></html>");
*/
{
ObjectInputStream inputFromApplet = null;
// this.gotoPage("/webcalendar/Register.jsp", request, response);
try
{
System.out.println("Inside doGet() in Servlet!");
// get an input stream from the applet
inputFromApplet = new ObjectInputStream(request.getInputStream());
String inString = (String) inputFromApplet.readObject();
// write back to applet
response.setContentType(CONTENT_TYPE);
ObjectOutputStream out = new ObjectOutputStream(response.getOutputStream());
String reply = "cool, you did it!";
out.writeObject(reply);
out.flush();
out.close();
inputFromApplet.close(); // close streams.
}
catch (Exception e)
{}
}
}
//Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
doGet(request, response);
}
//Clean up resources
public void destroy()
{
}
}
