Listing 1: Serve.java.
import java.net.*;
import java.io.*;
import java.awt.*;

public class Serve extends Frame implements Runnable{
Serve(){
setTitle("Server Program");
Panel p = new Panel();
portInput = new TextField(String.valueOf(port),4);
startButton = new Button("Start Server");
stopButton = new Button("Stop Server");
p.add(new Label("Port:"));
p.add(portInput);
p.add(startButton);
p.add(stopButton);
add("North",p);

a = new TextArea(50,30);
add("Center",a);
resize(300,300);
show();

}
public void run(){
port=Integer.parseInt(portInput.getText());
display("Server Started on Port:"+port+"\n");
try{
ss = new ServerSocket(port);
while(true){
display("listening again ** port: "+port+"\n");
Socket s = ss.accept();
new Thread(new FileRequest(s,this)).start();
display("got a file request \n");
}

} catch(Exception e){ display("$$$$ exception "+e+"\n");}
}
public boolean handleEvent(Event evt){
if(evt.id==Event.WINDOW_DESTROY){
System.exit(0);
return true;
}
if((evt.id==Event.ACTION_EVENT)&&(evt.target instanceof Button)){
if(runner != null){
runner.suspend();
display("Server Stopped By User\n");
}
}
if(evt.target == startButton){
if(runner == null){
runner = new Thread(this);
runner.start();
portInput.setEditable(false);
}else{runner.resume();
}
}
return super.handleEvent(evt);
 

}

public synchronized void display(String text){
a.appendText(text);
}
public static void main(String[] args){
new Serve();
}
private ServerSocket ss;
private TextArea a;
private int port = 80 ;
private TextField portInput;
private Button startButton, stopButton;
private Thread runner=null;
}

Listing 2: FileRequest.java
import java.io.*;
import java.net.*;
import java.util.*;

class FileRequest implements Runnable{
 

FileRequest(Socket s, Serve app){
this.app=app;
client = s;
}
public void run(){

if(requestRead()){
if(fileOpened()){
constructHeader();
if(fileSent()){
app.display("*File: "+fileName+" File Transfer Complete*Bytes Sent:"+bytesSent+"\n");
}
}
}
try{
dis.close();
client.close();
}catch(Exception e){app.display("Error closing Socket\n"+e);}

}
 

private boolean fileSent()
{
try{
DataOutputStream clientStream = new DataOutputStream(new BufferedOutputStream(client.getOutputStream()));
clientStream.writeBytes(header);
app.display("******** File Request *********\n"+
"******* "+ fileName +"*********\n"+header);
int i;
bytesSent = 0;
while((i=requestedFile.read()) != -1){
clientStream.writeByte(i);
bytesSent++;
}
clientStream.flush();
clientStream.close();
}catch(IOException e){return false;}
return true;

}
private boolean fileOpened()
{
try{
requestedFile = new DataInputStream(new BufferedInputStream (new FileInputStream("wwwroot/"+fileName)));
fileLength = requestedFile.available();
app.display(fileName+" is "+fileLength+" bytes long.\n");
}catch(FileNotFoundException e){
if(fileName.equals("filenfound.html")){return false;}
fileName="filenfound.html";
if(!fileOpened()){return false;}
}catch(Exception e){return false;}
 

return true;

}
private boolean requestRead()
{
try{
//Open inputStream and read(parse) the request
dis = new DataInputStream(client.getInputStream());
String line;
while((line=dis.readLine())!=null){

StringTokenizer tokenizer = new StringTokenizer(line," ");
if(!tokenizer.hasMoreTokens()){ break;}

if(tokenizer.nextToken().equals("GET")){

fileName = tokenizer.nextToken();
if(fileName.equals("/")){
fileName = "index.html";
}else{
fileName = fileName.substring(1);
}

}

}

}catch(Exception e){

return false;
}
app.display("finished file request");

return true;
}
 

private void constructHeader(){
String contentType;
if((fileName.toLowerCase().endsWith(".jpg"))||(fileName.toLowerCase().endsWith(".jpeg"))||(fileName.toLowerCase().endsWith(".jpe")))
{contentType = "image/jpg";}
else if((fileName.toLowerCase().endsWith(".gif")))
{contentType = "image/gif";}
else if((fileName.toLowerCase().endsWith(".htm"))||(fileName.toLowerCase().endsWith(".html")))
{contentType = "text/html";}
else if((fileName.toLowerCase().endsWith(".qt"))||(fileName.toLowerCase().endsWith(".mov")))
{contentType = "video/quicktime";}
else if((fileName.toLowerCase().endsWith(".class")))
{contentType = "application/octet-stream";}
else if((fileName.toLowerCase().endsWith(".mpg"))||(fileName.toLowerCase().endsWith(".mpeg"))||(fileName.toLowerCase().endsWith(".mpe")))
{contentType = "video/mpeg";}
else if((fileName.toLowerCase().endsWith(".au"))||(fileName.toLowerCase().endsWith(".snd")))
{contentType = "audio/basic";}
else if((fileName.toLowerCase().endsWith(".wav")))
{contentType = "audio/x-wave";}
else {contentType = "text/plain";} //default

header = "HTTP/1.0 200 OK\n"+
"Allow: GET\n"+
"MIME-Version: 1.0\n"+
"Server : HMJ Basic HTTP Server\n"+
"Content-Type: "+contentType + "\n"+
"Content-Length: "+ fileLength +
"\n\n";
}

private Serve app;
private Socket client;
private String fileName,header;
private DataInputStream requestedFile, dis;
private int fileLength, bytesSent;

}