Language Java Nosugar Comms Code Urltimestable.java

// 
//	URLtimestable class
//	part of the set of documents known as Java no sugar.
//	Copyright (c) 1996 Sunil Gupta, sunil@magnetic.demon.co.uk
//	placed into the public domain by the author
//
import java.awt.*;
import java.io.*;
import java.net.*;
import java.applet.*;
import java.util.*;
import UrlPostConnection;
import Document;

	
public class URLtimestable extends Applet
{

	//*******************************************************************
	// instance variables
	//*******************************************************************
	static final String HOSTPARAM = "HOSTNAME";
	static final String PORTPARAM = "PORTNAME";
	
	TextArea textarea;
	TextField txt_number, txt_count;
	Button btn_doit;
	
	//*******************************************************************
	// applet methods
	//*******************************************************************
	public void init()
	{
		GridBagConstraints c;
		GridBagLayout layout;
		Label label;
		
		//--------BUILD THE USER INTERFACE-------------------------
		layout = new GridBagLayout();
		this.setLayout( layout );
		
		//---------------------------------------------------------
		label = new Label("Number");
		c = new GridBagConstraints();
		c.gridx = 0; c.gridy = 0; c.gridwidth=1; c.gridheight=1;
		c.fill = GridBagConstraints.HORIZONTAL;
		layout.setConstraints(label,c);
		this.add(label);
		
		label = new Label("Count");
		c = new GridBagConstraints();
		c.gridx = 0; c.gridy = 1; c.gridwidth=1; c.gridheight=1;
		c.fill = GridBagConstraints.HORIZONTAL;
		layout.setConstraints(label,c);
		this.add(label);


		//---------------------------------------------------------
		txt_number = new TextField();
		c = new GridBagConstraints();
		c.gridx = 1; c.gridy = 0; c.gridwidth=1; c.gridheight=1;
		c.fill = GridBagConstraints.HORIZONTAL;
		layout.setConstraints(txt_number,c);
		this.add(txt_number);

		txt_count = new TextField();
		c = new GridBagConstraints();
		c.gridx = 1; c.gridy = 1; c.gridwidth=1; c.gridheight=1;
		c.fill = GridBagConstraints.HORIZONTAL;
		layout.setConstraints(txt_count,c);
		this.add(txt_count);

		//---------------------------------------------------------
		textarea = new TextArea();
		c = new GridBagConstraints();
		c.gridx = 0; c.gridy = 2; c.gridwidth=2; c.gridheight=2;
		c.fill = GridBagConstraints.BOTH;
		layout.setConstraints(textarea,c);
		this.add(textarea);
				
		//------------------------add button--------------------
		btn_doit = new Button("Do it");
		c = new GridBagConstraints();
		c.gridx = 2; c.gridy = 0; c.gridwidth=1; c.gridheight=1;
		c.fill = GridBagConstraints.HORIZONTAL;
		layout.setConstraints(btn_doit,c);
		this.add(btn_doit);
	}


	public boolean action(Event event, Object arg)
	{
		
		if (event.target == btn_doit)
		{
			do_times_url();
			return true;
		}
		return (false)	;
	}
	
	//
	// date is a safe choice since most httpd's implement this
	//
	private void do_times_url() throws NumberFormatException
	{
		URL applet_url;
		String protocol, data_line;
		String num,count;
		DataInputStream in_stream;
		PrintStream out_stream;
		UrlPostConnection connection;
		String script = "/cgi-bin/timestable.pl";
		String hostname, port_string;
		int port;
		Document document;
		Enumeration result_data;
		
		//------------------------------------------------------------------
		// clear out any text
		//
		textarea.setText("");
		
		//------------------------------------------------------------------
		// make sure applet is running from httpd
		//
		applet_url = this.getDocumentBase();
		protocol = applet_url.getProtocol();
		if ( ! protocol.equals("http") )
		{
			textarea.appendText(
				"This applet isnt being run from a server\n" +
				"and will not work unless you switch off the security\n" +
				"restrictions on your browser\n" );
				
			hostname =  getParameter(HOSTPARAM);
			if (hostname == null)
			{
				textarea.appendText("You need to supply a hostname in the " + HOSTPARAM + " paramater\n");
				return;
			}
			
			port_string = getParameter(PORTPARAM);
			if  ( port_string == null)
				port = 80;
			else
				port = Integer.parseInt(port_string);
		}
		else
		{
			textarea.appendText("Applet is on a server\n");
			hostname = applet_url.getHost();
			port = applet_url.getPort();
		}
		
		//------------------------------------------------------------------
		// BUILD URL netscape doesnt support POST so have to use a custom class.
		//
		connection = new UrlPostConnection(hostname, port, script);
		connection.setProperty("number", txt_number.getText() );
		connection.setProperty("count", txt_count.getText() );
		textarea.appendText( "Attempting to use URL " + connection.toString()+ "\n");
		
		try
		{
			document = connection.sendData();
		}
		catch (IOException e)
		{
			textarea.appendText("unable to connect to \n " + e +"\n");
			return;
		}

		//------------------------------------------------------------------
		// All was well if this point was reached, display string data"
		//
		result_data = document.body();
			while (result_data.hasMoreElements())
			{
				data_line = (String) result_data.nextElement();
				textarea.appendText(data_line +"\n");
			}
	}
}

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