aleung/HttpServer.java

## HttpServer.java
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.StringTokenizer;

public class HttpServer {
  public static void main(String args[]) {
    int port;
    try {
      port = Integer.parseInt(args[0]);
    } catch (Exception e) {
      port = 80;
    }

    String root;
    try {
      root = args[1];
    } catch (Exception e) {
      root = "../";
    }

    try {

      ServerSocket server_socket = new ServerSocket(port);
      System.out.println("HttpServer running on port "
          + server_socket.getLocalPort() + ", root directory is " + root);

      // server infinite loop
      while (true) {
        Socket socket = server_socket.accept();
        System.out.println("New connection accepted "
            + socket.getInetAddress() + ":" + socket.getPort());

        // Construct handler to process the HTTP request message.
        try {
          HttpRequestHandler request = new HttpRequestHandler(socket, root);
          // Create a new thread to process the request.
          Thread thread = new Thread(request);
          thread.start();
        } catch (Exception e) {
          System.out.println(e);
        }
      }
    } catch (IOException e) {
      System.out.println(e);
    }
  }
}

class HttpRequestHandler implements Runnable {
  final static String CRLF = "\r\n";

  Socket socket;
  InputStream input;
  OutputStream output;
  BufferedReader br;
  private String root;

  public HttpRequestHandler(Socket socket, String root) throws Exception {
    this.root = root;
    this.socket = socket;
    this.input = socket.getInputStream();
    this.output = socket.getOutputStream();
    this.br = new BufferedReader(new InputStreamReader(socket
        .getInputStream()));
  }

  public void run() {
    try {
      processRequest();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  private void processRequest() throws Exception {
    while (true) {
      String headerLine = br.readLine();
      System.out.println(">>>Request");
      System.out.println(headerLine);
      if (headerLine.equals(CRLF) || headerLine.equals(""))
        break;

      StringTokenizer s = new StringTokenizer(headerLine);
      String temp = s.nextToken();

      if (temp.equals("GET")) {

        String serverLine = "Server: Simple Java Http Server";
        String statusLine = null;
        String contentTypeLine = "text/html";
        String entityBody = null;
        String contentLengthLine = "";
        FileInputStream fis = null;
        boolean fileExists = false;

        String requestedPath = s.nextToken();
        if (requestedPath.equals("/")) {
          requestedPath = "";
        }
        String fileName = root + requestedPath;
        System.out.println("===Debug");
        System.out.println(fileName);
        File file = new File(fileName);
        if (!file.exists()) {
          statusLine = "HTTP/1.0 404 Not Found" + CRLF;
          entityBody = "<HTML>"
              + "<HEAD><TITLE>404 Not Found</TITLE></HEAD>"
              + "<BODY>404 Not Found"
              + "<br>usage:http://yourHostName:port/"
              + "fileName.html</BODY></HTML>";
        } else {
          statusLine = "HTTP/1.0 200 OK" + CRLF;

          if (file.isDirectory()) {
            String[] files = file.list();
            entityBody = "<HTML><HEAD><TITLE>" + file.getPath()
                + "</TITLE></HEAD><BODY><UL>";
            for (String entry : files) {
              entityBody += "<LI><a href='" + requestedPath + "/" + entry + "'>"
                + entry +"</a></LI>";
            }
            entityBody += "</UL></BODY></HTML>";
          } else {
            try {
              fis = new FileInputStream(file);
              fileExists = true;
            } catch (FileNotFoundException e) {
              e.printStackTrace();
            }
            contentTypeLine = "Content-type: " + contentType(fileName) + CRLF;
            contentLengthLine = "Content-Length: "
              + (new Integer(fis.available())).toString() + CRLF;
          }
        }

        if (!fileExists) {
            contentLengthLine = "Content-Length: "
              + (new Integer(entityBody.getBytes().length)).toString() + CRLF;
        }

        System.out.println("<<<Response");

        output.write(statusLine.getBytes());
        System.out.println(statusLine);
        output.write(serverLine.getBytes());
        System.out.println(serverLine);
        output.write(contentTypeLine.getBytes());
        System.out.println(contentTypeLine);
        output.write(contentLengthLine.getBytes());
        System.out.println(contentLengthLine);

        // Send a blank line to indicate the end of the header lines.
        output.write(CRLF.getBytes());
        System.out.println(CRLF);

        // Send the entity body.
        if (fileExists) {
          sendBytes(fis, output);
          fis.close();
        } else {
          output.write(entityBody.getBytes());
          System.out.println(entityBody);
        }

      }
    }

    try {
      output.close();
      br.close();
      socket.close();
    } catch (Exception e) {
    }
  }

  private static void sendBytes(FileInputStream fis, OutputStream os)
      throws Exception {

    byte[] buffer = new byte[1024];
    int bytes = 0;

    while ((bytes = fis.read(buffer)) != -1) {
      os.write(buffer, 0, bytes);
    }
  }

  private static String contentType(String fileName) {
    if (fileName.endsWith(".htm") || fileName.endsWith(".html")
        || fileName.endsWith(".txt")) {
      return "text/html";
    } else if (fileName.endsWith(".jpg") || fileName.endsWith(".jpeg")) {
      return "image/jpeg";
    } else if (fileName.endsWith(".gif")) {
      return "image/gif";
    } else {
      return "application/octet-stream";
    }
  }
}
	import java.io.BufferedReader;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.FileNotFoundException;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.InputStreamReader;
	import java.io.OutputStream;
	import java.net.ServerSocket;
	import java.net.Socket;
	import java.util.StringTokenizer;

	public class HttpServer {
	public static void main(String args[]) {
	int port;
	try {
	port = Integer.parseInt(args[0]);
	} catch (Exception e) {
	port = 80;
	}

	String root;
	try {
	root = args[1];
	} catch (Exception e) {
	root = "../";
	}

	try {

	ServerSocket server_socket = new ServerSocket(port);
	System.out.println("HttpServer running on port "
	+ server_socket.getLocalPort() + ", root directory is " + root);

	// server infinite loop
	while (true) {
	Socket socket = server_socket.accept();
	System.out.println("New connection accepted "
	+ socket.getInetAddress() + ":" + socket.getPort());

	// Construct handler to process the HTTP request message.
	try {
	HttpRequestHandler request = new HttpRequestHandler(socket, root);
	// Create a new thread to process the request.
	Thread thread = new Thread(request);
	thread.start();
	} catch (Exception e) {
	System.out.println(e);
	}
	}
	} catch (IOException e) {
	System.out.println(e);
	}
	}
	}

	class HttpRequestHandler implements Runnable {
	final static String CRLF = "\r\n";

	Socket socket;
	InputStream input;
	OutputStream output;
	BufferedReader br;
	private String root;

	public HttpRequestHandler(Socket socket, String root) throws Exception {
	this.root = root;
	this.socket = socket;
	this.input = socket.getInputStream();
	this.output = socket.getOutputStream();
	this.br = new BufferedReader(new InputStreamReader(socket
	.getInputStream()));
	}

	public void run() {
	try {
	processRequest();
	} catch (Exception e) {
	e.printStackTrace();
	}
	}

	private void processRequest() throws Exception {
	while (true) {
	String headerLine = br.readLine();
	System.out.println(">>>Request");
	System.out.println(headerLine);
	if (headerLine.equals(CRLF) \|\| headerLine.equals(""))
	break;

	StringTokenizer s = new StringTokenizer(headerLine);
	String temp = s.nextToken();

	if (temp.equals("GET")) {

	String serverLine = "Server: Simple Java Http Server";
	String statusLine = null;
	String contentTypeLine = "text/html";
	String entityBody = null;
	String contentLengthLine = "";
	FileInputStream fis = null;
	boolean fileExists = false;

	String requestedPath = s.nextToken();
	if (requestedPath.equals("/")) {
	requestedPath = "";
	}
	String fileName = root + requestedPath;
	System.out.println("===Debug");
	System.out.println(fileName);
	File file = new File(fileName);
	if (!file.exists()) {
	statusLine = "HTTP/1.0 404 Not Found" + CRLF;
	entityBody = "<HTML>"
	+ "<HEAD><TITLE>404 Not Found</TITLE></HEAD>"
	+ "<BODY>404 Not Found"
	+ "<br>usage:http://yourHostName:port/"
	+ "fileName.html</BODY></HTML>";
	} else {
	statusLine = "HTTP/1.0 200 OK" + CRLF;

	if (file.isDirectory()) {
	String[] files = file.list();
	entityBody = "<HTML><HEAD><TITLE>" + file.getPath()
	+ "</TITLE></HEAD><BODY><UL>";
	for (String entry : files) {
	entityBody += "<LI><a href='" + requestedPath + "/" + entry + "'>"
	+ entry +"</a></LI>";
	}
	entityBody += "</UL></BODY></HTML>";
	} else {
	try {
	fis = new FileInputStream(file);
	fileExists = true;
	} catch (FileNotFoundException e) {
	e.printStackTrace();
	}
	contentTypeLine = "Content-type: " + contentType(fileName) + CRLF;
	contentLengthLine = "Content-Length: "
	+ (new Integer(fis.available())).toString() + CRLF;
	}
	}

	if (!fileExists) {
	contentLengthLine = "Content-Length: "
	+ (new Integer(entityBody.getBytes().length)).toString() + CRLF;
	}

	System.out.println("<<<Response");

	output.write(statusLine.getBytes());
	System.out.println(statusLine);
	output.write(serverLine.getBytes());
	System.out.println(serverLine);
	output.write(contentTypeLine.getBytes());
	System.out.println(contentTypeLine);
	output.write(contentLengthLine.getBytes());
	System.out.println(contentLengthLine);

	// Send a blank line to indicate the end of the header lines.
	output.write(CRLF.getBytes());
	System.out.println(CRLF);

	// Send the entity body.
	if (fileExists) {
	sendBytes(fis, output);
	fis.close();
	} else {
	output.write(entityBody.getBytes());
	System.out.println(entityBody);
	}

	}
	}

	try {
	output.close();
	br.close();
	socket.close();
	} catch (Exception e) {
	}
	}

	private static void sendBytes(FileInputStream fis, OutputStream os)
	throws Exception {

	byte[] buffer = new byte[1024];
	int bytes = 0;

	while ((bytes = fis.read(buffer)) != -1) {
	os.write(buffer, 0, bytes);
	}
	}

	private static String contentType(String fileName) {
	if (fileName.endsWith(".htm") \|\| fileName.endsWith(".html")
	\|\| fileName.endsWith(".txt")) {
	return "text/html";
	} else if (fileName.endsWith(".jpg") \|\| fileName.endsWith(".jpeg")) {
	return "image/jpeg";
	} else if (fileName.endsWith(".gif")) {
	return "image/gif";
	} else {
	return "application/octet-stream";
	}
	}
	}