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Thread: Simple HTTP-Server

  1. #1
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    Jul 2012
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    Default Simple HTTP-Server

    Hey guys,

    after the OneShotHttpServer was running, I wanted to try out the extended version. Somehow theres a problem again. This time when I want to compile the .java in the command shell it says:

    Note: SimpleHTTpd2.java uses unchecked or unsafe operations.
    Note: Recompile with -Xlint:unchecked for details.
    Ok. So I found out how to compile with Xlint and it says:

    SimpleHttpd2.java:109: warning: [unchecked] unchecked call to put(K,V) as a member of the raw type Hashtable
    myHeaders.put(key, value);

    where K,V are type-variables:
    K extends Object declared in class Hashtable
    V extends Object declared in class Hashtable
    1 warning
    So.. theres something "wrong" with this method here in line 109?

    protected void setHeader(String key, String value){
           myHeaders.put(key, value);

    Here's the code for the whole programme:

    package httpServer;
    import java.io.*;
    import java.net.*;
    import java.util.*;
    public class SimpleHttpd2 extends Thread {
    protected Socket s = null;
    protected static File docRoot;
    protected static String canonicalDocRoot;
    public final static int HTTP_PORT = 8080;
    public final static String CRLF = "\r\n";
    public final static String PROTOCOL = "HTTP/1.0 ";
    public final static String SC_OK = "200 OK";
    public final static String SC_BAD_REQUEST = "400 Bad Request";
    public final static String SC_FORBIDDEN = "403 Forbidden";
    public final static String SC_NOT_FOUND = "404 Not Found";
    protected static Properties typeMap = new Properties();
    protected String statusCode = SC_OK;
    protected Hashtable myHeaders = new Hashtable();
    	public static void main(String[] args) {
    		try {
    			typeMap.load(new FileInputStream("index.html"));
    			docRoot = new File (".");
    			canonicalDocRoot = docRoot.getCanonicalPath();
    			ServerSocket listen = new ServerSocket(HTTP_PORT);
    				SimpleHttpd2 aRequest = new SimpleHttpd2(listen.accept());
    			catch(IOException e) {
    				System.err.println("Fehler: " + e.toString());
    	public SimpleHttpd2(Socket s) {
    		this.s = s;
    	public void run() {
    		try {
    			setHeader("Server", "SimpleHttpd2");
    			BufferedReader is = new BufferedReader(new InputStreamReader(s.getInputStream()));
    			DataOutputStream os = new DataOutputStream(s.getOutputStream());
    			String request = is.readLine();
    			System.out.println("Request: " + request);
    			StringTokenizer st = new StringTokenizer(request);
    			if ((st.countTokens()==3) && st.nextToken().equals("GET")) {
    				String filename = docRoot.getPath() + st.nextToken();
    				if (filename.endsWith("/") || filename.equals(""))
    					filename += "index.html";
    				File file = new File(filename);
    				if (file.getCanonicalPath().startsWith(canonicalDocRoot))
    					sendDocument(os, file);
    					sendError(SC_FORBIDDEN, os);
    			else {
    				sendError(SC_BAD_REQUEST, os);
    		catch ( IOException ioe) {
    			System.err.println("Fehler: " + ioe.toString());
    	protected void sendDocument(DataOutputStream os, File file) throws IOException {
    		try {
    			BufferedInputStream in = new BufferedInputStream (new FileInputStream(file));
    			setHeader("Content-Length", (new Long(file.length())).toString());
    			setHeader("Content-Type", guessType(file.getPath()));
    			byte[] buf = new byte[1024];
    			int len;
    			while ((len = in.read(buf, 0, 1024)) != -1) {
    				os.write(buf, 0, len);
    		catch (FileNotFoundException fnfe) {
    			sendError(SC_NOT_FOUND, os);
    	protected void setStatusCode(String statusCode) {
    		this.statusCode = statusCode;
    	protected String getStatusCode() {
    		return statusCode;
    	protected void sendStatusLine(DataOutputStream out) throws IOException {
    		out.writeBytes(PROTOCOL + getStatusCode() + CRLF);
    	protected void setHeader(String key, String value) {
    		myHeaders.put(key, value);
    	protected void sendHeader(DataOutputStream out) throws IOException {
    		String line;
    		String key;
    		Enumeration e = myHeaders.keys();
    		while (e.hasMoreElements()) {
    			key = (String)e.nextElement();
    			out.writeBytes(key + ": " + myHeaders.get(key) + CRLF);
    	protected void sendError(String statusCode, DataOutputStream out) throws IOException {
    				+ "<html>"
    				+ "<head><title>" + getStatusCode() + "</title></head>"
    				+ "<body><hl>" + getStatusCode() + "</hl></body>"
    				+ "</html>"
    	public String guessType(String filename) {
    		String type = null;
    		int i = filename.lastIndexOf(".");
    		if (i > 0)
    			type = typeMap.getProperty(filename.substring(i));
    		if (type == null)
    			type = "unknown/unknown";
    		return type;

    Is there someone out there who knows how to fix that problem?

    Zaphod_B.. do you have an idea?

    Edit: ok I put the index.html in the project folder this time the programme works with my IDE. However the header data etc is not given out as it should. Only "Request: GET / HTTP/1.1" Maybe theres something missing in the programme.

    Edit: I changed the out.writeBytes() stuff with System.out.println() and now he gives out a lot more. Dont know yet if everything works properly as it should, but at least it works better now. Someone knows why the out.writeBytes() dont work?

    Now the output when I enter http://localhost:8080/ in my browser is:

    Request: GET / HTTP/1.1
    HTTP/1.0 200 OK

    Server: SimpleHttpd2

    Content-Type: unknown/unknown

    Content-Length: 44

    Request: GET /favicon.ico HTTP/1.1
    HTTP/1.0 404 Not Found

    404 Not Found
    Request: GET /favicon.ico HTTP/1.1
    HTTP/1.0 404 Not Found

    404 Not Found
    And someone knows why there is 2x in the output:

    Request: GET /favicon.ico HTTP/1.1
    HTTP/1.0 404 Not Found

    404 Not Found
    Last edited by v1per1987; July 27th, 2012 at 06:50 AM.

  2. #2
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    Default Re: Simple HTTP-Server

    I dont know how to fix your server, but a small hint:
    Try to use the
    tags. It makes it so much easier to read for other people .

  3. The Following User Says Thank You to elamre For This Useful Post:

    v1per1987 (July 27th, 2012)

  4. #3
    Join Date
    Jun 2012
    Left Coast, USA
    My Mood
    Thanked 97 Times in 88 Posts

    Default Re: Simple HTTP-Server

    Quote Originally Posted by v1per1987 View Post
    ...compile the .java in the command ...
    protected void setHeader(String key, String value){
           myHeaders.put(key, value);
    There is nothing wrong with that line. The message was about the declaration of myHeaders.

    Change the declaration of myHeaders (somewhere around line 22)

    protected Hashtable myHeaders = new Hashtable();


    protected Hashtable<String,String> myHeaders = new Hashtable<String,String>();
    Quote Originally Posted by v1per1987
    Here's the code for the whole programme:

    			typeMap.load(new FileInputStream("index.html")); //<--- This doesn't make sense.  typeMap is used to identify the mime type of a file
    Change that line to
                typeMap.load(new FileInputStream("mime.types"));

    Create a file named "mime.types" in the same directory. Paste the following into mime.types:
    Quote Originally Posted by v1per1987
    I put the index.html in the project folder this time the programme works with my IDE
    Well, I can't see how it sends valid stuff to your browser when you try to use the server I mean, it can print a line in the console window where you launched the server, but as a server, it is kaput until you get a typeMap loaded.

    Quote Originally Posted by v1per1987
    Edit: I changed the out.writeBytes() stuff with System.out.println() and now he gives out a lot more.
    Well, System.out.println() writes stuff to the terminal window, and the writeBytes stuff is sending the stuff out the socket to service http requests, so getting things to print on the console can be a useful debugging tool, but it doesn't make it work as a server. That stuff has got to go out the socket! Go back to your original code. Change the typeMap declaration and do the mime.types thing I suggested. Try localhost:8080 from your browser again.

    Do you have an Ethernet packet sniffer like Wireshark? (Used to be called Ethereal.) If you don't, then I respectfully suggest that if you are going to be doing anything serious in the area of network programming that you install it.

    Bottom line: If the mime.types file is properly implemented, when you enter the "localhost:8080" in your browser URL window, you should see the processed html in the browser window.

    If index.html contains <html>Hi, Zaphod!</html>, you should see Hi, Zaphod! in the browser window. (Unlike the previous example, which showed the entire text contents of index.html, including the <> html tags.)

    Then--- it's time to have a little fun with more interesting index.html stuff before going to the next step.


    Last edited by Zaphod_b; July 27th, 2012 at 05:24 PM.

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