{"id":458,"date":"2007-12-01T00:00:00","date_gmt":"2007-11-30T16:00:00","guid":{"rendered":"http:\/\/www.strongd.net\/?p=458"},"modified":"2011-07-15T09:55:08","modified_gmt":"2011-07-15T01:55:08","slug":"demonstrates-the-functionality-of-datagramconnection-framework","status":"publish","type":"post","link":"https:\/\/www.strongd.net\/?p=458","title":{"rendered":"Demonstrates the functionality of DatagramConnection framework."},"content":{"rendered":"

\/*** Chapter 5 Sample Code for Datagram functionality ***\/

<\/FONT>import <\/B><\/FONT><\/FONT>javax.microedition.midlet.*;<\/FONT>
import <\/B><\/FONT>javax.microedition.lcdui.*;<\/FONT>
import <\/B><\/FONT>javax.microedition.io.*;<\/FONT>
import <\/B><\/FONT>java.util.*;<\/FONT>
<\/FONT>
public class <\/B><\/FONT>DatagramTest <\/FONT>extends <\/B><\/FONT>MIDlet <\/FONT>{<\/FONT>
<\/FONT>
  <\/FONT>\/\/ Port 9001 is used for datagram communication<\/FONT>
    <\/FONT>static final <\/B><\/FONT>int <\/B><\/FONT>receiveport  = <\/FONT>9001<\/FONT>;<\/FONT>
  <\/FONT>Receive receiveThread = <\/FONT>new <\/B><\/FONT>Receive<\/FONT>()<\/FONT>;<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>DatagramTest<\/FONT>() {<\/FONT>
  <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>startApp<\/FONT>() {<\/FONT>
        <\/FONT>\/\/ Start the listening thread<\/FONT>
        <\/FONT>receiveThread.start<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>\/\/ Send message Hello World!<\/FONT>
        <\/FONT>sendMessage<\/FONT>(<\/FONT>“Hello World!”<\/FONT>)<\/FONT>;<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>pauseApp<\/FONT>() {<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
    <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>destroyApp<\/FONT>(<\/FONT>boolean <\/B><\/FONT>unconditional<\/FONT>)  {<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
  <\/FONT>\/\/ This function sends a datagram message on port 9001.<\/FONT>
    <\/FONT>void <\/B><\/FONT>sendMessage<\/FONT>(<\/FONT>String msg<\/FONT>)  {<\/FONT>
    <\/FONT>String destAddr = <\/FONT>“datagram:\/\/localhost:” <\/FONT>+ receiveport;<\/FONT>
        <\/FONT>DatagramConnection dc = <\/FONT>null<\/B><\/FONT>;<\/FONT>
    <\/FONT>Datagram dgram;<\/FONT>
    <\/FONT>byte<\/B><\/FONT>[] <\/FONT>bMsg = msg.getBytes<\/FONT>()<\/FONT>;<\/FONT>
<\/FONT>
    <\/FONT>try <\/B><\/FONT>{<\/FONT>
           <\/FONT>dc = <\/FONT>(<\/FONT>DatagramConnection<\/FONT>)<\/FONT>Connector.open<\/FONT>(<\/FONT>destAddr<\/FONT>)<\/FONT>;<\/FONT>
      <\/FONT>\/\/ Create a datagram socket and send<\/FONT>
            <\/FONT>dgram= dc.newDatagram<\/FONT>(<\/FONT>bMsg,bMsg.length,destAddr<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>dc.send<\/FONT>(<\/FONT>dgram<\/FONT>)<\/FONT>;<\/FONT>
      <\/FONT>System.out.println<\/FONT>(<\/FONT>“Sending Packet:” <\/FONT>+  msg<\/FONT>)<\/FONT>;<\/FONT>
            <\/FONT>dc.close<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>}<\/FONT>
        <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>)  {<\/FONT>
            <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception Connecting: ” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
    <\/FONT>}<\/FONT>
    <\/FONT>finally <\/B><\/FONT>{<\/FONT>
            <\/FONT>if <\/B><\/FONT>(<\/FONT>dc != <\/FONT>null<\/B><\/FONT>) {<\/FONT>
                <\/FONT>try <\/B><\/FONT>{<\/FONT>
                    <\/FONT>dc.close<\/FONT>()<\/FONT>;<\/FONT>
                <\/FONT>}<\/FONT>
                <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>) {<\/FONT>
                   <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception Closing: ” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
                <\/FONT>}<\/FONT>
            <\/FONT>}<\/FONT>
        <\/FONT>}<\/FONT>
    <\/FONT>}<\/FONT>
<\/FONT>
  <\/FONT>\/\/ This function is a listener. It waits to receive datagram packets on 9001 port<\/FONT>
    <\/FONT>class <\/B><\/FONT>Receive <\/FONT>extends <\/B><\/FONT>Thread  <\/FONT>{<\/FONT>
        <\/FONT>public <\/B><\/FONT>void <\/B><\/FONT>run<\/FONT>() {<\/FONT>
        <\/FONT>doReceive<\/FONT>()<\/FONT>;<\/FONT>
        <\/FONT>}<\/FONT>
<\/FONT>
        <\/FONT>void <\/B><\/FONT>doReceive<\/FONT>() {<\/FONT>
            <\/FONT>DatagramConnection dc = <\/FONT>null<\/B><\/FONT>;<\/FONT>
            <\/FONT>Datagram dgram;<\/FONT>
      <\/FONT>try <\/B><\/FONT>{<\/FONT>
        <\/FONT>\/\/ Open Server side datagram connection<\/FONT>
                <\/FONT>dc = <\/FONT>(<\/FONT>DatagramConnection<\/FONT>)<\/FONT>Connector.open<\/FONT>(<\/FONT>“datagram:\/\/:”<\/FONT>+receiveport<\/FONT>)<\/FONT>;<\/FONT>
          <\/FONT>String receivedMsg;<\/FONT>
          <\/FONT>while <\/B><\/FONT>(<\/FONT>true<\/B><\/FONT>) {<\/FONT>
                    <\/FONT>dgram = dc.newDatagram<\/FONT>(<\/FONT>dc.getMaximumLength<\/FONT>())<\/FONT>;<\/FONT>
                <\/FONT>try <\/B><\/FONT>{<\/FONT>
             <\/FONT>dc.receive<\/FONT>(<\/FONT>dgram<\/FONT>)<\/FONT>;<\/FONT>
          <\/FONT>} <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>) {<\/FONT>
            <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception in receiving message:” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
          <\/FONT>}<\/FONT>
                    <\/FONT>receivedMsg = <\/FONT>new <\/B><\/FONT>String<\/FONT>(<\/FONT>dgram.getData<\/FONT>()<\/FONT>, <\/FONT>0<\/FONT>,dgram.getLength<\/FONT>())<\/FONT>;<\/FONT>
                    <\/FONT>System.out.println<\/FONT>(<\/FONT>“Received Message: ” <\/FONT>+ receivedMsg<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>try <\/B><\/FONT>{<\/FONT>
                       <\/FONT>Thread.sleep<\/FONT>(<\/FONT>500<\/FONT>)<\/FONT>;<\/FONT>
                    <\/FONT>}<\/FONT>
                    <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>) {<\/FONT>
                      <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception doReceive(): ” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
                    <\/FONT>}<\/FONT>
                <\/FONT>}<\/FONT>
<\/FONT>
            <\/FONT>}<\/FONT>
          <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>) {<\/FONT>
          <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception doReceive(): ” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
       <\/FONT>}<\/FONT>
       <\/FONT>finally <\/B><\/FONT>{<\/FONT>
          <\/FONT>if <\/B><\/FONT>(<\/FONT>dc != <\/FONT>null<\/B><\/FONT>) {<\/FONT>
          <\/FONT>try <\/B><\/FONT>{<\/FONT>
                       <\/FONT>dc.close<\/FONT>()<\/FONT>;<\/FONT>
                   <\/FONT>}<\/FONT>
                   <\/FONT>catch <\/B><\/FONT>(<\/FONT>Exception e<\/FONT>) {<\/FONT>
                      <\/FONT>System.out.println<\/FONT>(<\/FONT>“Exception Closing: ” <\/FONT>+ e.getMessage<\/FONT>())<\/FONT>;<\/FONT>
                   <\/FONT>}<\/FONT>
               <\/FONT>}<\/FONT>
          <\/FONT>}<\/FONT>
<\/FONT>
        <\/FONT>}<\/FONT>
     <\/FONT>}<\/FONT>
 <\/FONT>}<\/FONT><\/FONT>

\n

<\/DIV><\/p>\n","protected":false},"excerpt":{"rendered":"

\/*** Chapter 5 Sample Code for Datagram functionality ***\/import javax.microedition.midlet.*;import javax.microedition.lcdui.*;import javax.microedition.io.*;import java.util.*;public class DatagramTest extends MIDlet {  \/\/ Port 9001 is used for datagram communication    static final int receiveport  = 9001;  Receive receiveThread = new Receive();    public DatagramTest() {  }    public void startApp() {        \/\/ Start the listening thread        receiveThread.start();        \/\/ Send message Hello World!        sendMessage(“Hello World!”);    }    public void pauseApp() {    }    public void destroyApp(boolean unconditional)  {    }  \/\/ This function sends a datagram message on port 9001.    void sendMessage(String msg)  {    String destAddr = “datagram:\/\/localhost:” + receiveport;        DatagramConnection dc = null;    Datagram dgram;    byte[] bMsg = msg.getBytes();    try {           dc = (DatagramConnection)Connector.open(destAddr);      \/\/ Create a datagram socket and send            dgram= dc.newDatagram(bMsg,bMsg.length,destAddr);            dc.send(dgram);      System.out.println(“Sending Packet:” +  msg);            dc.close();        }        catch (Exception e)  {            System.out.println(“Exception Connecting: ” + e.getMessage());    }    finally {            if (dc != null) {                try {                    dc.close();                }                catch (Exception e) {                   System.out.println(“Exception Closing: ” + e.getMessage());                }            }        }    }  \/\/ This function is a listener. It waits to receive datagram packets on 9001 port    class Receive extends Thread  {        public void run() {        doReceive();        }        void doReceive() {            DatagramConnection dc = null;            Datagram dgram;      try {        \/\/ Open Server side datagram connection                dc = (DatagramConnection)Connector.open(“datagram:\/\/:”+receiveport);          String receivedMsg;          while (true) {                    dgram = dc.newDatagram(dc.getMaximumLength());                try {             dc.receive(dgram);          } catch (Exception e) {            System.out.println(“Exception in receiving message:” + e.getMessage());          }                    receivedMsg = new String(dgram.getData(), 0,dgram.getLength());                    System.out.println(“Received Message: ” + receivedMsg);                    try {                       Thread.sleep(500);                    }                    catch (Exception e) {                      System.out.println(“Exception doReceive(): ” + e.getMessage());                    }                }            }          catch (Exception e) {          System.out.println(“Exception doReceive(): ” + e.getMessage());       }       finally {          if (dc != null) {          try {                       dc.close();                   }                   catch (Exception e) {                      System.out.println(“Exception Closing: ” + e.getMessage());                   }               }          }        }     } }<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[132],"class_list":["post-458","post","type-post","status-publish","format-standard","hentry","category-java","tag-datagramconnection"],"_links":{"self":[{"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/posts\/458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.strongd.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=458"}],"version-history":[{"count":1,"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/posts\/458\/revisions"}],"predecessor-version":[{"id":934,"href":"https:\/\/www.strongd.net\/index.php?rest_route=\/wp\/v2\/posts\/458\/revisions\/934"}],"wp:attachment":[{"href":"https:\/\/www.strongd.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.strongd.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.strongd.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}