Listing 1: Create a Socket Object
try{
ourSocket = new Socket(serverName, 80);
}catch(UnknownHostException e){
//..code if the host does not exist
}catch(IOException e){
System.out.println(" Unable to open the Socket to "+serverName);
}

Listing 2: Establish input and output streams.
try{
ourInputStream = ourSocket.getInputStream();
ourOutputStream = ourSocket.getOutputStream();
}catch(IOException e){
System.out.println("unable to open streams");
}

Listing 3: Closing the socket.
try{
ourSocket.close();
}catch(IOException e){
System.out.println("Exception thrown closing the Socket");
}

Listing 4
*/
public class SocketClient extends Frame implements Runnable{
/* ******* Data Section ******** */
TextField theServer,theFile;
TextArea theHTMLCode;
Thread thread;
Button search, stopSearch;
Socket ourSocket;

/**
* This is the default constructor for this class. Its job is to initialize
* the SocketClient object. We construct a Frame Window here. A data entry
* panel is created and added "North". Here a user will be able to enter a server
* name and a file to retrieve. If no file name is specified, index.html will be the
* default file to search for.
*/
public SocketClient(){

setTitle("Socket Client Example");
//Set the frame window title.
setLayout(new BorderLayout());
//Set the layout for the window.
theServer = new TextField("www.",20);
//Create the data entry fields.
theFile = new TextField("",20);
theHTMLCode = new TextArea("",25,100);
theHTMLCode.setEditable(false);
//Make the TextArea not editable.

Panel pan = new Panel();
//Make a panel to contain the data
pan.setLayout(new FlowLayout());
// entry fields and set the layout.
pan.add(new Label("http://"));
//Add text labels to the panel as
pan.add(theServer);
// well as the Data Entry Objects.
pan.add(new Label("/"));
pan.add(theFile);
search= new Button("Get the file");
stopSearch= new Button("Stop");

pan.add(search);
pan.add(stopSearch);
 

add("North",pan);
//Add the panel North.
add("Center",theHTMLCode);
//Add the TextArea Center.

thread = new Thread(this);
//Create a new thread.
resize(640,300);
//Resize the Window to an appropriate size.
show();
//Display the Window.
}

Listing 5: HandleEvent Method.
/**
* This is the handleEvent method. We provide code for the events triggered
* from a user pressing a button or destroying the window (Exiting the program).
* @param Event e
* @see event
*/
public boolean handleEvent(Event e){
if(e.target == search){
//If the Search Button was pressed, do this.
thread.stop();
if(theFile.getText().equals("")){
//If no file was specified
theFile.setText("index.html");
// set the file name to index.html.
}
theHTMLCode.setText("Looking Up Server: "+theServer.getText());
thread = new Thread(this);
thread.start();
//This calls the run() method for this.
return true;
}
if(e.target == stopSearch){
//If the Stop Button was pressed, do this.
thread.stop();
theHTMLCode.setText("Operation aborted by user");
return true;
}
if(e.id ==Event.WINDOW_DESTROY){
//If the user wants to exit the program.
System.exit(0);
//Notice how we do not need to return here.
}
return super.handleEvent(e);
//If we do not handle the event, pass it up the chain.
}

Listing 6: Run Method
/**
* This is the run method. It will open a socket connection to a web server and then
* get the input and output streams. Then we will simulate the way a web browser
* asks the server for a file with the GET statement. After that, we will read the
* text data from the web server.
*/
public void run(){
//Get the Socket and Streams
try{
ourSocket = new Socket(theServer.getText(),80);
DataInputStream inStream
//Notice how we kill a few birds with one stone.
= new DataInputStream(ourSocket.getInputStream());
DataOutputStream outStream
//Here too!
= new DataOutputStream(ourSocket.getOutputStream());
 

Listing 7: File Request String.
/* Here we construct a file request string. Since we are using
* a HTTP server, we need to simulate a file request. We do this
* like: GET /filename HTTP/1.0\r\n\r\n
* Notice that two ctrl/lf sequences are needed at the end of the request
*/
String requestString ="GET /"+ theFile.getText()+" HTTP/1.0\r\n"+ "\r\n";
theHTMLCode.appendText("\n The Request String is:\n"+requestString);
outStream.writeBytes(requestString);
//Send the Request to the HTTP server
outStream.flush();
//Don't forget to flush the stream.
theHTMLCode.appendText("\n ....Asking for file:"+theFile.getText());

//Read the file until EOF.
StringBuffer buff = new StringBuffer();
String currLine;
while((currLine = inStream.readLine())!=null){
buff.append(currLine + "\n");
}
theHTMLCode.setText(buff.toString());
//Place the text into the Text Area.

//Close the Socket
ourSocket.close();

}
catch(Exception e){ /* Since several exceptions can be thrown, We can catch all of them
* with the base class for Exceptions.
*/
theHTMLCode.setText("Exception with: "+e.getMessage()+"\n"+e.toString());
}
}

Listing 8: Main Method.
/** This is the main method. Program execution begins here
*/
public static void main(String[] args){
new SocketClient();
}

}