I will rate Lifesaver for some decent help! This program is for a web server wri
ID: 3639094 • Letter: I
Question
I will rate Lifesaver for some decent help! This program is for a web server written in Java. One class is WebServer which sets the port number, establishes a socket, and passes the request to the second class, HttpRequest, which is supposed to set a response back to the host. The server can receive the request (in the form of http://localhost:6789/index.html) but does not send a response message back. I'm not sure why. Please help!import java.io.*;
import java.net.*;
import java.util.*;
public final class WebServer
{
public static void main(String argv[]) throws Exception
{
// Set the port number.
int port = 6789;
// Establish the listen socket.
ServerSocket welcomeSocket = null;
try
{
welcomeSocket = new ServerSocket(port);
}
catch (IOException e)
{
System.out.println("Could not listen on port: 6789");
System.exit(-1);
}
// Process HTTP service requests in an infinite loop.
Socket connectionSocket = null;
while(true)
{
connectionSocket = welcomeSocket.accept();
// Construct an object to process the HTTP request message.
HttpRequest request = new HttpRequest(connectionSocket);
// Create a new thread to process the request.
Thread thread = new Thread(request);
// Start the thread.
thread.start();
}
}
}
import java.io.*;
import java.net.*;
import java.util.*;
final class HttpRequest implements Runnable
{
final static String CRLF = "/r/n";
Socket socket;
// Constructor
public HttpRequest(Socket socket) throws Exception
{
this.socket = socket;
}
// Implement the run() method of the Runnable interface.
public void run()
{
try
{
processRequest();
}
catch (Exception e)
{
System.out.println(e);
}
}
private void processRequest() throws Exception
{
// Get a reference to the socket's input and output streams.
InputStream is = socket.getInputStream();
DataOutputStream os = new DataOutputStream(socket.getOutputStream());
// Set up the input stream filters.
BufferedReader br = new BufferedReader(new InputStreamReader(is));
// Get the request line of the HTTP request message.
String requestLine = br.readLine();
// Display the request line.
System.out.println();
System.out.println(requestLine);
// Get and display the header lines.
String headerLine = null;
while ((headerLine = br.readLine()).length() != 0)
{
System.out.println(headerLine);
}
// Extract the filename from the request line.
StringTokenizer tokens = new StringTokenizer(requestLine);
// Skip over the method, which should be "GET"
tokens.nextToken();
String fileName = tokens.nextToken();
// Prepend a "." so that file request is within the current directory
fileName = "." + fileName;
// Open the requested file.
FileInputStream fis = null;
boolean fileExists = true;
try
{
fis = new FileInputStream(fileName);
}
catch (FileNotFoundException e)
{
fileExists = false;
}
// Construct the response message.
String statusLine = null;
String contentTypeLine = null;
String entityBody = null;
if (fileExists)
{
statusLine = "HTTP/1.0 200 OK" + CRLF;
contentTypeLine = "Content-type: " + contentType( fileName ) + CRLF;
}
else
{
statusLine = "HTTP/1.0 404 Not Found" + CRLF;
contentTypeLine = "No content to display.";
entityBody = "<HTML>" +
"<HEAD><TITLE>Not Found</TITLE></HEAD>" +
"<BODY>Not Found</BODY></HTML>";
}
// Send the status line.
os.writeBytes(statusLine);
// Send the content type line.
os.writeBytes(contentTypeLine);
// Send a blank line to indicate the end of the header lines.
os.writeBytes(CRLF);
// Send the entity body.
if (fileExists)
{
sendBytes(fis, os);
fis.close();
}
else
{
os.writeBytes(CRLF);
}
// Close streams and socket.
os.close();
br.close();
socket.close();
}
private static void sendBytes(FileInputStream fis, OutputStream os) throws Exception
{
// Construct a 1K buffer to hold bytes on their way to the socket.
byte[] buffer = new byte[1024];
int bytes = 0;
// Copy requested file into the socket's output stream.
while((bytes = fis.read(buffer)) != -1)
{
os.write(buffer, 0, bytes);
}
}
private static String contentType(String fileName)
{
if(fileName.endsWith(".htm") || fileName.endsWith(".html"))
{
return "text/html";
}
if(fileName.endsWith(".gif"))
{
return "image/gif";
}
if(fileName.endsWith(".jpeg") || fileName.endsWith(".jpg"))
{
return "image/jpeg";
}
return "application/octet-stream";
}
}
Explanation / Answer
I'm not sure how much of your problem this is responsible for, but you should change
final static String CRLF = "/r/n";
to
final static String CRLF = " ";
if you want to be RFC2616-compliant.