[+/-] : MIDlet examples to invoke a servlet

import java.io.*;
import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

/**
 * An example MIDlet to invoke a servlet.
 */

public class InvokeServletMidlet1 extends MIDlet {

   private Display display;

   String url = "http://127.0.0.1:8080/examples/servlet/HelloServlet";


   public InvokeServletMidlet1() {
      display = Display.getDisplay(this);
   }

   /**
    * Initialization. Invoked when we activate the MIDlet.
    */
   public void startApp() {
      try {
         invokeServlet(url);
      } catch (IOException e) {
         System.out.println("IOException " + e);
         e.printStackTrace();
      }
   }

   /**
    * Pause, discontinue ....
    */
   public void pauseApp() {
   }

   /**
    * Destroy must cleanup everything.
    */
   public void destroyApp(boolean unconditional) {
   }

   /**
    * Retrieve a grade....
    */
   void invokeServlet(String url) throws IOException {
      HttpConnection c = null;
      InputStream is = null;
      StringBuffer b = new StringBuffer();
      TextBox t = null;
      try {
         c = (HttpConnection)Connector.open(url);
         c.setRequestMethod(HttpConnection.GET);
         c.setRequestProperty("User-Agent","Profile/MIDP-1.0 Confirguration/CLDC-1.0");
         c.setRequestProperty("Content-Language", "en-CA");
         is = c.openDataInputStream();
         int ch;
         while ((ch = is.read()) != -1) {
            b.append((char) ch);
         }
         t = new TextBox("First Servlet", b.toString(), 1024, 0);
      } finally {
         if(is!= null) {
            is.close();
         }
         if(c != null) {
            c.close();
         }
      }
      display.setCurrent(t);
   }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import java.io.*;
import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

/**
 * An example MIDlet to invoke a CGI script (GET method).
 */

public class InvokeCgiMidlet1 extends MIDlet {

   private Display display;

   String url = "http://www.javacourses.com/cgi-bin/getgrade.cgi?idnum=182016";

   public InvokeCgiMidlet1() {
      display = Display.getDisplay(this);
   }

   /**
    * Initialization. Invoked when we activate the MIDlet.
    */
   public void startApp() {
      try {
         getGrade(url);
      } catch (IOException e) {
         System.out.println("IOException " + e);
         e.printStackTrace();
      }
   }

   /**
    * Pause, discontinue ....
    */
   public void pauseApp() {
   }

   /**
    * Destroy must cleanup everything.
    */
   public void destroyApp(boolean unconditional) {
   }

   /**
    * Retrieve a grade....
    */

   void getGrade(String url) throws IOException {
      HttpConnection c = null;
      InputStream is = null;
      OutputStream os = null;
      StringBuffer b = new StringBuffer();
      TextBox t = null;
      try {
         c = (HttpConnection)Connector.open(url);
         c.setRequestMethod(HttpConnection.GET);
         c.setRequestProperty("User-Agent","Profile/MIDP-1.0 Confirguration/CLDC-1.0");
         c.setRequestProperty("Content-Language", "en-CA");
         os = c.openOutputStream();
         /*
          String str = "?idnum=182016";
          byte postmsg[] = str.getBytes();
          for(int i=0;i<postmsg.length;i++) {
            os.writeByte(postmsg[i]);
          }
          os.flush();
          */
         is = c.openDataInputStream();
         int ch;
         while ((ch = is.read()) != -1) {
            b.append((char) ch);
            System.out.println((char)ch);
         }
         t = new TextBox("Final Grades", b.toString(), 1024, 0);
      } finally {
         if(is!= null) {
            is.close();
         }
         if(os != null) {
            os.close();
         }
         if(c != null) {
            c.close();
         }
      }
      display.setCurrent(t);
   }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import java.io.*;
import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

/**
 * An example MIDlet to invoke a CGI script (POST method is used).
 */

public class InvokeCgiMidlet2 extends MIDlet {

   private Display display;

   String url = "http://www.javacourses.com/cgi-bin/pgrade.cgi";

   public InvokeCgiMidlet2() {
      display = Display.getDisplay(this);
   }

   /**
    * Initialization. Invoked when we activate the MIDlet.
    */
   public void startApp() {
      try {
         getGrade(url);
      } catch (IOException e) {
         System.out.println("IOException " + e);
         e.printStackTrace();
      }
   }

   /**
    * Pause, discontinue ....
    */
   public void pauseApp() {
   }

   /**
    * Destroy must cleanup everything.
    */
   public void destroyApp(boolean unconditional) {
   }

   /**
    * Retrieve a grade....
    */

   void getGrade(String url) throws IOException {
      HttpConnection c = null;
      InputStream is = null;
      OutputStream os = null;
      StringBuffer b = new StringBuffer();
      TextBox t = null;
      try {
         c = (HttpConnection)Connector.open(url);
         c.setRequestMethod(HttpConnection.POST);
         c.setRequestProperty("CONTENT-TYPE","application/x-www-form-urlencoded");
         c.setRequestProperty("User-Agent","Profile/MIDP-1.0 Confirguration/CLDC-1.0");
         c.setRequestProperty("Content-Language", "en-CA");
         os = c.openOutputStream();

         // send input
         String str = "name=182016";
         byte postmsg[] = str.getBytes();
         for(int i=0;i<postmsg.length;i++) {
            os.write(postmsg[i]);
         }
         os.flush();
         is = c.openDataInputStream();
         int ch;
         // receive output
         while ((ch = is.read()) != -1) {
            b.append((char) ch);
            System.out.println((char)ch);
         }
         t = new TextBox("Final Grades", b.toString(), 1024, 0);
      } finally {
         if(is!= null) {
            is.close();
         }
         if(os != null) {
            os.close();
         }
         if(c != null) {
            c.close();
         }
      }
      display.setCurrent(t);
   }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import javax.microedition.rms.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import javax.microedition.io.*;
import java.io.*;

public class InvokeServletMidlet2 extends MIDlet implements CommandListener {
   Display display = null;
   List menu = null;
   TextBox input = null;
   String user = null;

   String url = "http://127.0.0.1:8080/examples/servlet/RequestServlet2";
   static final Command backCommand = new Command("Back", Command.BACK, 0);
   static final Command submitCommand = new Command("Submit", Command.OK, 2);
   static final Command exitCommand = new Command("Exit", Command.STOP, 3);
   String currentMenu = null;

   public InvokeServletMidlet2() {
   }

   public void startApp() throws MIDletStateChangeException {
      display = Display.getDisplay(this);
      menu = new List("Invoke Servlet", Choice.IMPLICIT);
      menu.append("Add a user", null);
      menu.addCommand(exitCommand);
      menu.setCommandListener(this);
      mainMenu();
   }

   public void pauseApp() {
   }

   public void destroyApp(boolean unconditional) {
      notifyDestroyed();
   }

   void mainMenu() {
      display.setCurrent(menu);
   }

   public void addName() {
      input = new TextBox("Enter first name:", "", 5, TextField.ANY);
      input.addCommand(submitCommand);
      input.addCommand(backCommand);
      input.setCommandListener(this);
      input.setString("");
      display.setCurrent(input);
   }

   void invokeServlet(String url) throws IOException {
      HttpConnection c = null;
      InputStream is = null;
      OutputStream os = null;
      StringBuffer b = new StringBuffer();
      TextBox t = null;
      try {
         c = (HttpConnection)Connector.open(url);
         c.setRequestMethod(HttpConnection.POST);
         c.setRequestProperty("CONTENT-TYPE","application/x-www-form-urlencoded");
         c.setRequestProperty("User-Agent","Profile/MIDP-1.0 Confirguration/CLDC-1.0");
         c.setRequestProperty("Content-Language", "en-CA");

         os = c.openOutputStream();
         String str = "name="+user;
         byte postmsg[] = str.getBytes();
         System.out.println("Length: "+str.getBytes());
         for(int i=0;i<postmsg.length;i++) {
            os.write(postmsg[i]);
         }
         // or you can easily do:
         //os.write(("name="+user).getBytes());
         os.flush();

         is = c.openDataInputStream();
         int ch;
         while ((ch = is.read()) != -1) {
            b.append((char) ch);
            System.out.print((char)ch);
         }
         t = new TextBox("Second Servlet", b.toString(), 1024, 0);
         t.addCommand(backCommand);
         t.setCommandListener(this);
      } finally {
         if(is!= null) {
            is.close();
         }
         if(os != null) {
            os.close();
         }
         if(c != null) {
            c.close();
         }
      }
      display.setCurrent(t);
   }

   public void commandAction(Command c, Displayable d) {
      String label = c.getLabel();
      if (label.equals("Exit")) {
         destroyApp(true);
      } else if (label.equals("Back")) {
         mainMenu();
      } else if (label.equals("Submit")) {
         user = input.getString();
         try {
            invokeServlet(url);
         }catch(IOException e) {}
      } else {
         addName();
      }
   }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import java.io.*;
import javax.microedition.io.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;

public class FetchPageMidlet extends MIDlet {

   private Display display;

   String url = "http://www.javacourses.com/hello.txt";

   public FetchPageMidlet() {
      display = Display.getDisplay(this);
   }

   /**
    * This will be invoked when we start the MIDlet
    */
   public void startApp() {
      try {
         getViaStreamConnection(url);
      } catch (IOException e) {
         //Handle Exceptions any other way you like.
         System.out.println("IOException " + e);
         e.printStackTrace();
      }
   }

   /**
    * Pause, discontinue ....
    */
   public void pauseApp() {

   }

   /**
    * Destroy must cleanup everything.
    */
   public void destroyApp(boolean unconditional) {
   }

   /**
    * read url via stream connection
    */
   void getViaStreamConnection(String url) throws IOException {
      StreamConnection c = null;
      InputStream s = null;
      StringBuffer b = new StringBuffer();
      TextBox t = null;
      try {
         c = (StreamConnection)Connector.open(url);
         s = c.openInputStream();
         int ch;
         while((ch = s.read()) != -1) {
            b.append((char) ch);
         }
         System.out.println(b.toString());
         t = new TextBox("Fetch Page", b.toString(), 1024, 0);
      } finally {
         if(s != null) {
            s.close();
         }
         if(c != null) {
            c.close();
         }
      }
      // display the contents of the file in a text box.
      display.setCurrent(t);
   }

}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import java.io.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
 * Example servlet showing request headers
 */

public class RequestServlet2 extends HttpServlet {


    public void doPost(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {
        response.setContentType("text/plain");
        PrintWriter out = response.getWriter();
        BufferedReader br = request.getReader();
        String buf = br.readLine();
        out.print("Rec: "+buf);
    }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 * The simplest possible servlet.
 */

public class HelloServlet extends HttpServlet {

    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {
        response.setContentType("text/plain");
        PrintWriter out = response.getWriter();

        out.println("Servlet  invoked!  ");
        out.println(new Date());
    }
}

/**
*   Wireless Java
*   Help for New J2ME Developers
*   By Qusay Mahmoud
*   First Edition January 2002
*   ISBN: 0-596-00243-2
*/

...
Read more

[+/-] : Socket MIDlet example code(J2ME)

package ora.ch6;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.StreamConnection;
import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.StringItem;
import javax.microedition.lcdui.TextField;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class SocketMIDlet extends MIDlet
                    implements CommandListener, Runnable {

    private Display display;
    private Form addressForm;
    private Form connectForm;
    private Form displayForm;
    private TextField serverName;
    private TextField serverPort;
    private StringItem messageLabel;
    private StringItem errorLabel;
    private Command okCommand;
    private Command exitCommand;
    private Command backCommand;

    protected void startApp() throws MIDletStateChangeException {
        if (display == null) {
            initialize();
            display.setCurrent(addressForm);
        }
    }

    protected void pauseApp() {
    }

    protected void destroyApp(boolean unconditional)
                        throws MIDletStateChangeException {
    }

    public void commandAction(Command cmd, Displayable d) {
        if (cmd == okCommand) {
            Thread t = new Thread(this);
            t.start();
            display.setCurrent(connectForm);
        } else if (cmd == backCommand) {
            display.setCurrent(addressForm);
        } else if (cmd == exitCommand) {
            try {
                destroyApp(true);
            } catch (MIDletStateChangeException ex) {
            }
            notifyDestroyed();
        }
    }

    public void run() {
        InputStream is = null;
        OutputStream os = null;
        StreamConnection socket = null;

        try {
            String server = serverName.getString();
            String port = serverPort.getString();
            String name = "socket://" + server + ":" + port;
            socket = (StreamConnection)Connector.open(name, Connector.READ_WRITE);
        } catch (Exception ex) {
            Alert alert = new Alert("Invalid Address",
                        "The supplied address is invalid\n" +
                        "Please correct it and try again.", null,
                        AlertType.ERROR);
            alert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert, addressForm);
            return;
        }

        try {
            // Send a message to the server
            String request = "GET / HTTP/1.0\n\n";

            os = socket.openOutputStream();
            os.write(request.getBytes());
            os.close();

            // Read the server's reply, up to a maximum
            // of 128 bytes.
            is = socket.openInputStream();
            final int MAX_LENGTH = 128;
            byte[] buf = new byte[MAX_LENGTH];
            int total = 0;
            while (total < MAX_LENGTH) {
                int count = is.read(buf, total, MAX_LENGTH - total);
                if (count < 0) {
                    break;
                }
                total += count;
            }
            is.close();
            String reply = new String(buf, 0, total);
            messageLabel.setText(reply);
            socket.close();
            display.setCurrent(displayForm);
        } catch (IOException ex) {
            Alert alert = new Alert("I/O Error",
                        "An error occurred while communicating with the server.",
                        null, AlertType.ERROR);
            alert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert, addressForm);
            return;
        } finally {
            // Close open streams and the socket
            try {
                if (is != null) {
                    is.close();
                    is = null;
                }
            } catch (IOException ex1) {
            }
            try {
                if (os != null) {
                    os.close();
                    os = null;
                }
            } catch (IOException ex1) {
            }
            try {
                if (socket != null) {
                    socket.close();
                    socket = null;
                }
            } catch (IOException ex1) {
            }
        }
    }

    private void initialize() {
        display = Display.getDisplay(this);

        // Commands
        exitCommand = new Command("Exit", Command.EXIT, 0);
        okCommand = new Command("OK", Command.OK, 0);
        backCommand = new Command("Back", Command.BACK, 0);

        // The address form
        addressForm = new Form("Socket Client");
        serverName = new TextField("Server name:", "", 256, TextField.ANY);
        serverPort = new TextField("Server port:", "", 8, TextField.NUMERIC);
        addressForm.append(serverName);
        addressForm.append(serverPort);
        addressForm.addCommand(okCommand);
        addressForm.addCommand(exitCommand);
        addressForm.setCommandListener(this);

        // The connect form
        connectForm = new Form("Connecting");
        messageLabel = new StringItem(null, "Connecting...\nPlease wait.");
        connectForm.append(messageLabel);
        connectForm.addCommand(backCommand);
        connectForm.setCommandListener(this);

        // The display form
        displayForm = new Form("Server Reply");
        messageLabel = new StringItem(null, null);
        displayForm.append(messageLabel);
        displayForm.addCommand(backCommand);
        displayForm.setCommandListener(this);
    }
}
J2ME in a Nutshell
By Kim Topley
First Edition March 2002
Series: In a Nutshell
ISBN: 0-596-00253-X

...
Read more

[+/-] : Http MIDlet example code(J2ME)

Really working examples categorized by API, package, class. You can compile and run our examples right away! Not from source code for Java projects - only working examples! Copy, compile and run!

package ora.ch6;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.lcdui.Alert;
import javax.microedition.lcdui.AlertType;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.StringItem;
import javax.microedition.lcdui.TextField;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

public class HttpMIDlet extends MIDlet
                    implements CommandListener, Runnable {

    private Display display;
    private Form addressForm;
    private Form connectForm;
    private Form displayForm;
    private TextField serverURL;
    private StringItem messageLabel;
    private StringItem errorLabel;
    private Command okCommand;
    private Command exitCommand;
    private Command backCommand;

    protected void startApp() throws MIDletStateChangeException {
        if (display == null) {
            initialize();
            display.setCurrent(addressForm);
        }
    }

    protected void pauseApp() {
    }

    protected void destroyApp(boolean unconditional)
                        throws MIDletStateChangeException {
    }

    public void commandAction(Command cmd, Displayable d) {
        if (cmd == okCommand) {
            Thread t = new Thread(this);
            t.start();
            display.setCurrent(connectForm);
        } else if (cmd == backCommand) {
            display.setCurrent(addressForm);
        } else if (cmd == exitCommand) {
            try {
                destroyApp(true);
            } catch (MIDletStateChangeException ex) {
            }
            notifyDestroyed();
        }
    }

    public void run() {
        InputStream is = null;
        HttpConnection conn = null;

        try {
            String url = serverURL.getString();
            if (!url.startsWith("http://") &&
         !url.startsWith("https://")) {
                url = "http://" + url;
            }
            conn = (HttpConnection)Connector.open(url, Connector.READ_WRITE);
        } catch (Exception ex) {
      System.out.println(ex);
      ex.printStackTrace();
            Alert alert = new Alert("Invalid Address",
                        "The supplied address is invalid\n" +
                        "Please correct it and try again.", null,
                        AlertType.ERROR);
            alert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert, addressForm);
            return;
        }

        try {
            // Fetch the required page, reading up
            // to a maximum of 128 bytes
            if (conn.getResponseCode() == HttpConnection.HTTP_OK) {
                is = conn.openInputStream();
                final int MAX_LENGTH = 128;
                byte[] buf = new byte[MAX_LENGTH];
                int total = 0;
                while (total < MAX_LENGTH) {
                    int count = is.read(buf, total, MAX_LENGTH - total);
                    if (count < 0) {
                        break;
                    }
                    total += count;
                }
                is.close();
                String reply = new String(buf, 0, total);
                messageLabel.setText(reply);
            } else {
                messageLabel.setText("Failed: error " + conn.getResponseCode() +
                                "\n" + conn.getResponseMessage());
            }

            // Get the response code and print all the headers
            System.out.println("Response code = " + conn.getResponseCode());
            System.out.println("Response message = " + conn.getResponseMessage());
            for (int i = 0; ; i++) {
                String key = conn.getHeaderFieldKey(i);
                String value = conn.getHeaderField(i);
                if (key == null) {
                    // Reached last header
                    break;
                }
                System.out.println(key + " = " + value);
            }
            conn.close();
            display.setCurrent(displayForm);
        } catch (IOException ex) {
      System.out.println(ex);
      ex.printStackTrace();
            Alert alert = new Alert("I/O Error",
                        "An error occurred while communicating with the server.",
                        null, AlertType.ERROR);
            alert.setTimeout(Alert.FOREVER);
            display.setCurrent(alert, addressForm);
            return;
        } finally {
            // Close open streams
           try {
                if (is != null) {
                    is.close();
                    is = null;
                }
            } catch (IOException ex1) {
            }
            try {
                if (conn != null) {
                    conn.close();
                    conn = null;
                }
            } catch (IOException ex1) {
            }
        }
    }

    private void initialize() {
        display = Display.getDisplay(this);

        // Commands
        exitCommand = new Command("Exit", Command.EXIT, 0);
        okCommand = new Command("OK", Command.OK, 0);
        backCommand = new Command("Back", Command.BACK, 0);

        // The address form
        addressForm = new Form("HTTP Client");
        serverURL = new TextField("URL:", "", 256, TextField.ANY);
        addressForm.append(serverURL);
        addressForm.addCommand(okCommand);
        addressForm.addCommand(exitCommand);
        addressForm.setCommandListener(this);

        // The connect form
        connectForm = new Form("Connecting");
        messageLabel = new StringItem(null, "Connecting...\nPlease wait.");
        connectForm.append(messageLabel);
        connectForm.addCommand(backCommand);
        connectForm.setCommandListener(this);

        // The display form
        displayForm = new Form("Server Reply");
        messageLabel = new StringItem(null, null);
        displayForm.append(messageLabel);
        displayForm.addCommand(backCommand);
        displayForm.setCommandListener(this);
    }
}
J2ME in a Nutshell
By Kim Topley
First Edition March 2002
Series: In a Nutshell
ISBN: 0-596-00253-X

...
Read more