The 1st assignment of Computer Network: Java Web Server

WebServer.java

import java.net.*;
import java.util.*; //for ArrayList and Date
import java.io.*;

class ConnectionThread extends Thread {
  Socket client; //class member
    int counter; //class member
    //constructor
    public ConnectionThread(Socket cl, int c) {
        client = cl;
        counter = c;
    }
    public void ReturnErrorHead(String sc, PrintWriter o) {//sc->Status Code, wrong always HTTP 1.1!!!
        if (sc.equals("301")) {
            o.println("HTTP/1.1 301 Moved Permanent");
            //DATE TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            //Location to designate new place???
            
            o.println("Content-Length: 313");
            //o.println("Content-Length:" + fileToSend.length());
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        } else if(sc.equals("304")) {
            o.println("HTTP/1.1 304 Not Modified");
            //DATE
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            o.println("ETag: \"c0e92-b1-4d42ba994aa00\"");
            o.println("Vary: Accept-Encoding");
            
            //not page return
        } else if (sc.equals("400")) {
            o.println("HTTP/1.1 400 Bad Request");
            //Date:
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            o.println("Vary: Accept-Encoding");
            o.println("Content-Length: 301");
            //o.println("Content-Length:" + fileToSend.length());
            o.println("Connection: close"); // must be closed, because it's wrong
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();

        } else if(sc.equals("403")) {
            o.println("HTTP/1.1 403 Forbidden");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            o.println("Vary: Accept-Encoding");
            o.println("Content-Length: 288");
            //o.println("Connection: close"); // must be closed, because it's wrong
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        } else if(sc.equals("404")) {
            o.println("HTTP/1.1 404 Not Found");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            o.println("Content-Length: 207");
            o.println("Connection: close"); // must be closed, because it's wrong
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        } else if(sc.equals("405")) {
            o.println("HTTP/1.1 405 Method Not Allowed");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            //o.println("Content-Location: index.html.en");//don't know it's meaning
            o.println("Vary: negotiate");
            o.println("TCN: choice");
            o.println("Allow: GET,HEAD,OPTIONS");
            o.println("Content-Length: 308");
            o.println("Connection: close"); // must be closed, because it's wrong
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        } else if(sc.equals("412")) {
            ////////////////////////////////////////////////
            //I don't know how to do
            ////////////////////////////////////////////////
            o.println("HTTP/1.1 412 Precondition Failed");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            //o.println("Content-Location: index.html.en");

            //o.println("Last-Modified: Fri, 08 Feb 2013 20:32:48 GMT");
            //Last Modified
            
            o.println("ETag: \"11638e1-0-4d53c76661c00\"");
            o.println("Accept-Ranges: bytes");
            o.println("Content-Length: 0");
            //o.println("Connection: close");
            o.println("Content-Type: text/html");
            o.println();

            //No Content Return
        } else if(sc.equals("501")) {
            o.println("HTTP/1.1 501 Method Not Implemented");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            //o.println("Content-Location: index.html.en");
            o.println("Vary: negotiate");
            o.println("TCN: choice");
            o.println("Allow: GET,HEAD,OPTIONS");
            o.println("Content-Length: 299");
            //o.println("Connection: close"); // must be closed, because it's wrong
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        } else if(sc.equals("505")) {
            o.println("HTTP/1.1 505 HTTP Version Not Supported");
            //TIME
            
            o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
            o.println("Vary: negotiate");
            o.println("TCN: choice");
            o.println("Content-Length: 283");
            o.println("Content-Type: text/html; charset=iso-8859-1");
            o.println();
            
        }
    }
    public void ReturnErrorPage(String sc, PrintWriter o, String m, String f) {
        if (sc.equals("301")) {     
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>301 Moved Permanently</title>");
            o.println("</head><body>");
            o.println("<h1>Moved Permanently</h1>");
            o.println("<p>The document has moved <a href=\"http://192.168.1.8/test_dir/\">here</a>.</p>");
            o.println("</body></html>");
        } else if(sc.equals("304")) {

            //not page return
        } else if (sc.equals("400")) {
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>400 Bad Request</title>");
            o.println("</head><body>");
            o.println("<h1>Bad Request</h1>");
            o.println("<p>Your browser sent a request that this server could not understand.</p>");
            o.println("</body></html>");
        } else if(sc.equals("403")) {
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>403 Forbidden</title>");
            o.println("</head><body>");
            o.println("<h1>Forbidden</h1>");
            o.println("<p>You don't have permission to access " + f + " + on this server.</p>");
            o.println("</body></html>");
            
        } else if(sc.equals("404")) {
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>404 Not Found</title>");
            o.println("</head><body>");
            o.println("<h1>Not Found</h1>");
            o.println("<p>The requested URL " + f + " was not found on this server.</p>");
            o.println("</body></html>");
        } else if(sc.equals("405")) {
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>405 Method Not Allowed</title>");
            o.println("</head><body>");
            o.println("<h1>Method Not Allowed</h1>");
            o.println("The requested method " + m + " is not allowed for the URL " + f + ".");
            o.println("</body></html>");
        } else if(sc.equals("412")) {
            //No Content Return
        } else if(sc.equals("501")) {
            //content
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>501 Method Not Implemented</title>");
            o.println("</head><body>");
            o.println("<h1>Method Not Allowed</h1>");
            o.println("The requested method " + m + " is not allowed for the URL " + f + ".");
            o.println("</body></html>");
        } else if(sc.equals("505")) {
            o.println("<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">");
            o.println("<html><head>");
            o.println("<title>505 HTTP Version Not Supported</title>");
            o.println("</head><body>");
            o.println("<h1>HTTP Version Not Supported</h1>");
            o.println("The HTTP Version of your requested is not allowed for the URL " + f + ".");
            o.println("</body></html>");
        }
    }
    public void ReturnHead(File f, String hv, PrintWriter o) {
        o.println(hv + " 200 OK");//"HTTP/1.x 200 OK"
        //TIME
        
        o.println("Server: JAVA Web Server/0.1 (Wei_Lin)");
        o.println("Vary: negotiate");
        o.println("TCN: choice");
        //LAST MODIFIED
        
        o.println("ETag: \"154d00-2c-4c5c7409c6e00\"");
        o.println("Accept-Ranges: bytes");
        o.println("Content-Length:" + f.length());
        o.println("Content-Type: text/html");
        o.println("Content-Language: en");
        o.println();
    }
    public void ReturnPage(File f, PrintWriter o) {
        BufferedReader fileOut;
        try {
            fileOut = new BufferedReader(new FileReader(f));
            String content;
            while((content = fileOut.readLine()) != null) {
                o.println(content);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public void ReturnOptions(PrintWriter o, String hv) {
        o.println("HTTP/1.1 200 OK");
        //DATE
        //o.println("Date: Fri, 08 Feb 2013 02:55:06 GMT");
        o.println("Server: JAVA Web Server/0.1  (Wei_Lin)");
        //o.println("Content-Location: index.html.en");
        o.println("Vary: negotiate");
        o.println("TCN: choice");
        o.println("Allow: GET,HEAD,OPTIONS");
        o.println("Content-Length: 0");
        //o.println("Connection: close");
        o.println("Content-Type: text/html");
        o.println("Content-Language: en");
        //o.println();
        o.close();
    }
    public void DealRequest(String method, String file, String hv, PrintWriter o) {
        File fileToSend = new File("/var/www" + file);
        //add /index.html if is a directory
        boolean isDirectory = false;
        if(fileToSend.isDirectory() && file.charAt(file.length()-1) == '/') {//example: file = "/test_dir/"
            isDirectory = true;
            fileToSend = new File("/var/www" + file + "index.html");
        } else if(fileToSend.isDirectory() && file.charAt(file.length()-1) != '/') {//example: file = "/test_dir"
            isDirectory = true;
            fileToSend = new File("/var/www" + file + "/index.html");
        } //else: normal file, no need to add /index.html
            
        System.out.println(fileToSend.toString());
        
        //
        
        //System.out.println(fileToSend.toString());
        if(method.equals("GET")) {
            if(fileToSend.exists() && fileToSend.canRead()) {
                ReturnHead(fileToSend, hv, o);
                ReturnPage(fileToSend, o);
                //ReturnFile(fileToSend.toString(), o, hv); 
            } else if(fileToSend.exists() && !fileToSend.canRead()) {
                ReturnErrorHead("403", o);
                ReturnErrorPage("403", o, method, file);
            } else if(!fileToSend.exists() && !isDirectory) {
                //!!!!!
                ReturnErrorHead("404", o);
                ReturnErrorPage("404", o, method, file);
            } else if(!fileToSend.exists() && isDirectory) {
                ReturnErrorHead("301", o);
                ReturnErrorPage("301", o, method, file);
            }
            
        } else if(method.equals("HEAD")) {
            /*Last Things*/
            /*Remove ReturnHead, compare to GET*/


        } else if(method.equals("OPTIONS")) {
            
            ReturnOptions(o, hv);
        } else if(method.equals("POST") || method.equals("PUT") || method.equals("DELETE") || method.equals("TRACE") || method.equals("CONNECT")) {
            //method not allowed
            ReturnErrorHead("405", o);
            ReturnErrorPage("405", o, method, file);
        } else {
            //method not implement
            ReturnErrorHead("501", o);
            ReturnErrorPage("501", o, method, file);
        }
    }

    //class method
    public void run() {//throws IOException {   
        //boolean timeout = true;
        boolean persistent = true;
        while(persistent) {
            //System.out.println("Begin of while!");
            try {
                //Test multi-thread and persistent connection
                String destIP = client.getInetAddress().toString();
                int destport = client.getPort();
                System.out.println("Thread " + counter + ": Connected from " + destIP + " on port " + destport + ".");  
                
                BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
                PrintWriter out = new PrintWriter(client.getOutputStream(), true);
                String request = null;
                String tempHeader = null;
                ArrayList<String> header = new ArrayList<String>();
                
                request = in.readLine();
                int headerNo = 0;
                boolean containHost = false;
                boolean containModified = false;
                boolean containUnmodified = false;
                
                while((tempHeader = in.readLine()).length() != 0) {//Control to receive a space line
                    header.add(tempHeader);
                    headerNo++;
                    if(tempHeader.split(":")[0].equalsIgnoreCase("Host")) {
                        containHost = true;
                    }
                    if(tempHeader.split(":")[0].equalsIgnoreCase("If-Modified-Since")) {
                        containModified = true;
                        //containUnmodified = true;
                    }
                    if(tempHeader.split(":")[0].equalsIgnoreCase("If-Unmodified-Since")) {
                        //containModified = true;
                        containUnmodified = true;
                    }
                }
                //System.out.println(request);
                /*
                for(int i = 0; i < headerNo; i++) {
                    System.out.println(header.get(i));
                }
            
                System.out.println();
                */
                //Think about the persistent control
                
                String[] subRequest = request.split(" ");
                
                //Can't exist both M and Unm
                if(containModified == true && containUnmodified == true) {
                    ReturnErrorHead("400", out);
                    ReturnErrorPage("400", out, subRequest[0], subRequest[1]);
                }
                
                ///////////////////////////////////////////////////////////////////////////////
                //Request with less than 2 spaces
                ///////////////////////////////////////////////////////////////////////////////
                if (subRequest.length <= 2) {//no enough space, 400
                    //400
                    ReturnErrorHead("400", out);
                    ReturnErrorPage("400", out, subRequest[0], subRequest[1]);
                    //persistent = false;
                }
                ///////////////////////////////////////////////////////////////////////////////
                //HTTP 1.1
                ///////////////////////////////////////////////////////////////////////////////
                else if(subRequest[2].equals("HTTP/1.1") && containHost) {
                    //beginning of persistent connection
                    //System.out.println("HTTP 1.1");
                    //System.out.println(subRequest[1]);
                    DealRequest(subRequest[0], subRequest[1], subRequest[2], out);
                ///////////////////////////////////////////////////////////////////////////////
                //HTTP 1.0
                ///////////////////////////////////////////////////////////////////////////////
                } else if(subRequest[2].equals("HTTP/1.0")) {
                    //non-persistent
                    //System.out.println("HTTP 1.0");
                    //the same as 1.1, just change persistent to false
                    ReturnErrorHead("505", out);
                    ReturnErrorPage("505", out, subRequest[0], subRequest[1]);
                    /*
                    //DealRequest(subRequest[0], subRequest[1], subRequest[2], out);
                    //persistent = false;
                     *
                     */
                ///////////////////////////////////////////////////////////////////////////////
                //Wrong: Example: (!HTTP 1.0 || !HTTP 1.0) || (1.1 without Host)
                ///////////////////////////////////////////////////////////////////////////////
                } else if((!subRequest[2].equals("HTTP/1.0") || !subRequest[2].equals("HTTP/1.1")) || subRequest[2].equals("HTTP/1.1") && !containHost) {
                    //400
                    ReturnErrorHead("400", out);
                    ReturnErrorPage("400", out, subRequest[0], subRequest[1]);
                    //persistent = false;
                }
                
            } catch(IOException e) {
                try {
                    //timeout = true;
                    persistent = false;
                    System.out.println("Thread " + counter + " Timeout!");
                    client.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
                System.out.println(e);
            }
            
        }
        if(!persistent) { 
            //EXIT the persistent
            try {
                //this is for timeout connection
                client.close();
                System.out.println("Thread " + counter + " Closed!");
                System.out.println("Server disconnect!");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

public class WebServer {
    public static void main(String[] args) throws IOException {
        int i = 0;
        int port = 12000;
        ServerSocket server = null;
        Socket client = null;
        server = new ServerSocket(port);
        System.out.println("JAVA Web Server on port " + server.getLocalPort());
        while(true) {
            try {
                
                client = server.accept();
                client.setSoTimeout(10000);
                new ConnectionThread(client, i).start();
                i++;
            } catch(Exception e) {
                System.out.println(e);
                client.close();
            }
            //client.close();
        }
        //server.close();

    }
}