Socket communication external web server (Apache)

[Rácz György]

Hi!

Sorry for my bad english! I have got a big problem... I develop struts web application java 6 with apache tomcat. This web application one most important function is read RSS sites. One RSS site (www.ft.com/rss/world) redirected (statusCode = 302), so I connect this site with Socket and send GET /rss/world HTTP/1.0 User-Agent: Wget/1.9.1 message, respose I give RSS site in XML format. This is work fine in sample java programme, but not in web application.
Simple java program source code:

 
        Socket socket = null;
        try {
            InetAddress addr = InetAddress.getByName("www.ft.com");
            int port = 80;
        
            // This constructor will block until the connection succeeds
            socket = new Socket(addr, port);
        } catch (UnknownHostException e) {
        } catch (IOException e) {
        }

        try {
            BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            wr.write("GET /rss/world HTTP/1.0");
            wr.newLine();
            wr.write("\nUser-Agent: Wget/1.9.1");
            wr.flush();
        } catch (IOException e) {
        	System.out.println("exception get: "+e);
        }
       
        try {
  	    BufferedReader rd = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            String str;
            
            BufferedWriter out = new BufferedWriter(new FileWriter("ft.xml"));

            boolean hasWriteFile = false;
            while ((str = rd.readLine()) != null) {
            	if ((!hasWriteFile) && (!"".equals(str)) && (str != null) && (str.length()>5)){
            		if ((str.substring(0, 5).equals("<?xml"))){
            			hasWriteFile = true;
            		}
            	}
            	if (hasWriteFile) {
            		out.write(str);
            	}
                System.out.println(str);
            }
           
            out.close();
            rd.close(); 

And here is my web application class code:

	public static void writeRSSSiteToXMLFile(String site){
		Socket socket = null;
		String str = null;
		try {
			InetAddress addr = InetAddress.getByName("www.ft.com");
			int port = 80; 
			
			socket = new Socket(addr, port);
			
			System.out.println("socket closed: "+socket.isClosed());
			System.out.println("socket connected: "+socket.isConnected());
			
			BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
			wr.write("GET /rss/world HTTP/1.0");
			wr.newLine();
			wr.write("User-Agent: Wget/1.9.1");
			wr.flush();
			
			BufferedReader rd = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			BufferedWriter out = new BufferedWriter(new FileWriter("d:\\cemift.xml"));
	
			boolean hasWriteFile = false;
            while ((str = rd.readLine()) != null) {
            	if ((!hasWriteFile) && (!"".equals(str)) && (str != null) && (str.length()>5)){
            		if ((str.substring(0, 5).equals("<?xml"))){
            			hasWriteFile = true;
            		}
            	}
            	if (hasWriteFile) {
            		out.write(str);
            	}
                System.out.println(str);
            }
            out.close();
            rd.close();
		} catch (UnknownHostException e) {
			System.out.println("UnknownHostException: "+e);			
		} catch (NullPointerException e) {
			System.out.println("NullPointerException: "+e);
        } catch (IOException e) {
        	System.out.println("IOException: "+e);        	
        }
	}

When the program execute on while ((str = rd.readLine()) != null) { then nothing happend...no exception but my web app not response!

Please help me!

[Rácz György]

Hi Coders!

I set up socket.setSoTimeout(2000); then I receive java.net.SocketTimeoutException: Read timed out. The socket connected: true and socket closed: false.

How can I read the socket correctly?
How can I handle SocketTimeoutException?

Please help me!

[William Brogden]

Is there a reason you are using raw sockets?

Why not use the classes in the standard Java library - see the java.net package for classes like HttpURLConnection. This is a class designed to handle all the tricky socket details for you.

Bill

[Rácz György]

William Brogden wrote:Is there a reason you are using raw sockets?

Why not use the classes in the standard Java library - see the java.net package for classes like HttpURLConnection. This is a class designed to handle all the tricky socket details for you.

Bill

Hi Bill!

Here is some line from my NewsAction source code. If statusCode = 301 vagy 302 (site redirect) then I need read RSS xml file with Socket.

How I read redirected site with HttpURLConnection?

    
if (ns.getSiteURL() != null) {
        boolean badRSSSite = false;
        ChannelIF channel = null;
	ChannelFormat format;
	try {
		URL	url = new URL(ns.getSiteURL());
		//test site						
		HttpURLConnection.setFollowRedirects(false);
		HttpURLConnection con = (HttpURLConnection) url.openConnection();
		int statusCode = con.getResponseCode();
		if ((statusCode == 301) | (statusCode == 302)) {
			badRSSSite = true; //redirected site
                        //call writeRSSSiteToXMLFile
			RSS.writeRSSSiteToXMLFile(ns.getSiteURL());

Thank you! Please post example source code...

Best regards!

[Rácz György]

R�cz Gy�rgy wrote:

William Brogden wrote:Is there a reason you are using raw sockets?

Why not use the classes in the standard Java library - see the java.net package for classes like HttpURLConnection. This is a class designed to handle all the tricky socket details for you.

Bill

Hi Bill!

Here is some line from my NewsAction source code. If statusCode = 301 vagy 302 (site redirect) then I need read RSS xml file with Socket.

How I read redirected site with HttpURLConnection?

    
if (ns.getSiteURL() != null) {
        boolean badRSSSite = false;
        ChannelIF channel = null;
	ChannelFormat format;
	try {
		URL	url = new URL(ns.getSiteURL());
		//test site						
		HttpURLConnection.setFollowRedirects(false);
		HttpURLConnection con = (HttpURLConnection) url.openConnection();
		int statusCode = con.getResponseCode();
		if ((statusCode == 301) | (statusCode == 302)) {
			badRSSSite = true; //redirected site
                        //call writeRSSSiteToXMLFile
			RSS.writeRSSSiteToXMLFile(ns.getSiteURL());

Thank you! Please post example source code...

Best regards!

Hi Coders!

I found what is the problem...I copy my source code and create a new thick (not a web app) java program, this java code work fine, I received the RSS XML file. Then I comment the following lines in my new thick java application, and I received same IOException: java.net.SocketTimeoutException: Read timed out exception as my web application. So in Apache webapp I can't write my request to the Socket. I dont know why! Can anybody help me? Why I cannot write to the output socket OutputStream?

   
try {
            BufferedWriter wr = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
            wr.write("GET /rss/world HTTP/1.0");
            wr.newLine();
            wr.write("\nUser-Agent: Wget/1.9.1");
            wr.flush();
        } catch (IOException e) {
        	System.out.println("exception get: "+e);
        }
 

[Christophe Verré]

(sorry to disturb, but you can fix your display name in My Profile)