aleung
11/8/2011 - 1:47 PM

Tiny HTTP Server by Java, only supports GET method.

Tiny HTTP Server by Java, only supports GET method.

HttpServer.java
content_copyfile_download
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";
    }
  }
}