<form action="http://www.javacourses.com/servlets/getMarks method="GET">
Student#:
<input type=text name=number size=30>
<input type=submit name=GetMarks value=GetMarks>
</form>

200 OK: Request succeeded. The requested resource can be found later in this message. 
301 Moved Permanently: Requested resource has moved. New location is specified later in this message. 
400 Bad Request: Request message is not understood by the server. 
404 Not Found: Requested document is not found on this server. 

GET / HTTP/1.1
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, 
application/vnd.ms-powerpoint, application/vnd.ms-excel, 
application/msword, */*
Accept-Language: en-ca
Accept-Encoding: gzip, deflate
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows 98; YComp 5.0.0.0)
Host: java.sun.com
Connection: Keep-Alive
Cookie: SUN_ID=24.80.19.177:28346100732290; 
SunONEUserId=24.80.19.177:86521021960770

HTTP/1.1 200 OK
Server: Netscape-Enterprise/6.0
Date: Mon, 14 Oct 2002 15:18:04 GMT
Content-type: text/html
Connection: close

import java.net.*;
import java.io.*;


public class ReadURL1 {
public static void main(String argv[]) throws Exception {
final int HTTP_PORT = 80;
if(argv.length != 1) {
System.out.println("Usage: java ReadURL1 <url>");
System.exit(0);
}

Socket socket = new Socket(argv[0], HTTP_PORT);
BufferedWriter out= new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
BufferedReader in= new BufferedReader(new InputStreamReader(socket.getInputStream()));
out.write("GET /index.html HTTP/1.0\n\n");
out.flush();
String line;
StringBuffer sb = new StringBuffer();
while((line = in.readLine()) != null) {
sb.append(line);
}
out.close();
in.close();
System.out.println(sb.toString());
}
}

// end code

import java.net.*;
import java.io.*;

public class ReadURL2 {

public static void main(String argv[]) throws Exception {
if(argv.length != 1) {
System.out.println("Usage: java ReadURL2 <url>");
System.exit(0);
}

URL url = new URL(argv[0]);
BufferedReader in= new BufferedReader(new InputStreamReader(url.openStream()));
String line;
StringBuffer sb = new StringBuffer();

while ((line = in.readLine()) != null) {
sb.append(line);
}
in.close();
System.out.println(sb.toString());

}

}

public class Stock {

private static String name, time, price;

// Given a quote from the server,
// retrieve the name, price, and date of the stock
public static void parse(String data) {

int index = data.indexOf('"');
name = data.substring(++index,(index = data.indexOf('"', index)));
index +=3;
time = data.substring(index, (index = data.indexOf('-', index))-1);
index +=5;
price = data.substring(index, (index = data.indexOf('>', index)));
}

// Get the name of the stock from
public static String getName(String record) {
parse(record);
return(name);
}

// Get the price of the stock from
public static String getPrice(String record) {
parse(record);
return(price);
}

// Get the date of the stock
public static String getDate(String record) {
parse(record);;
return time;
}
}

import java.io.*;
import java.net.*;

public class StockReader {
public static void main(String argv[]) throws Exception {
String quoteFormat = "&f=slc1wop";
if (argv.length != 1) {
System.err.println("Usage: java StockReader <symbol>");
System.exit(1);
}

URL url = new URL("http://quote.yahoo.com/d/quotes.csv?");
URLConnection connection = url.openConnection();
connection.setDoOutput(true);

PrintWriter out = new PrintWriter(connection.getOutputStream());
out.println("s=" + argv[0] + quoteFormat);
out.close();

BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line = in.readLine();

/* DEBUG
while ((line = in.readLine()) != null) {
System.out.println("Got: "+ line);
}
*/
in.close();
System.out.println("Name: "+ Stock.getName(line));
System.out.println("Price: "+ Stock.getPrice(line));
System.out.println("Date: "+ Stock.getDate(line));
}
}

import java.io.*;
import java.net.*;

public class PostExample {
public static void main(String[] argv) throws Exception {
URL url = new URL("http://www.javacourses.com/cgi-bin/names.cgi");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setDoOutput(true);
PrintWriter out = new PrintWriter(connection.getOutputStream());
// encode the message
String name = "name="+URLEncoder.encode("Qusay Mahmoud", "UTF-8");
String email = "email="+URLEncoder.encode("qmahmoud@javacourses.com", "UTF-8");
// send the encoded message
out.println(name+"&"+email);
out.close();
BufferedReader in= new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
in.close();
}
}

http.proxyHost (default: )
http.proxyPort (default: 80 if http.proxyHost specified)
http.nonProxyHosts (default: )

ftp.proxyHost (default: )
ftp.proxyPort (default: 80 if ftp.proxyHost specified)
ftp.nonProxyHosts (default: )

<tomcat-users>
<user name="tomcat" password="tomcat" roles="tomcat" />
<user name="role1" password="tomcat" roles="role1" />
<user name="both" password= "tomcat" roles="tomcat,role1" />
<user name="qusay" password="guesswhat" roles="author" />
<user name="reader" password="youguess" roles="reader" />
</tomcat-users>

6. <?xml version="1.0" encoding="ISO-8859-1"?>
7. 
8. <!DOCTYPE web-app
9. PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
10. "http://java.sun.com/dtd/web-app_2_3.dtd">
11. 
12. <web-app>
13. 
14. <description>
15. Learning Web Programming
16. </description>
17. 
18. <security-constraint>
19. <web-resource-collection>
20. <web-resource-name>
21. Restricted Area
22. </web-resource-name>
23. <url-pattern>/chapter/*</url-pattern>
24. </web-resource-collection>
25. <auth-constraint>
26. <role-name>tomcat</role-name>
27. <role-name>author</role-name>
28. <role-name>reader</role-name>
29. </auth-constraint>
30. </security-constraint>
31. 
32. <login-config>
33. <auth-method>BASIC</auth-method>
34. <realm-name>Authenticate yourself</realm-name>
35. </login-config>
36. 
</web-app>

import java.net.*;
import java.awt.*;
import javax.swing.*;

public class AuthImpl extends Authenticator {
protected PasswordAuthentication getPasswordAuthentication() {
JTextField username = new JTextField();
JTextField password = new JPasswordField();
JPanel panel = new JPanel(new GridLayout(2,2));
panel.add(new JLabel("User Name"));
panel.add(username);
panel.add(new JLabel("Password") );
panel.add(password);
int option= JOptionPane.showConfirmDialog(null,
new Object[] {"Site: "+getRequestingHost(),
"Realm: "+getRequestingPrompt(),panel},
"Enter Network Password",
JOptionPane.OK_CANCEL_OPTION,
JOptionPane.PLAIN_MESSAGE);
if ( option == JOptionPane.OK_OPTION ) {
String user = username.getText();
char pass[] = password.getText().toCharArray();
return new PasswordAuthentication(user, pass);
} else {
return null;
}
}
}

import java.io.*;
import java.net.*;

public class BasicReader {
public static void main(String argv[]) throws Exception {
Authenticator.setDefault(new AuthImpl());
if (argv.length != 1) {
System.err.println("Usage: java BasicReader <site>");
System.exit(1);
}
URL url = new URL(argv[0]);
URLConnection connection = url.openConnection();
BufferedReader in= new BufferedReader(new InputStreamReader(connection.getInputStream()));

String line;
StringBuffer sb = new StringBuffer();
while ((line = in.readLine()) != null) {
sb.append(line);
}
in.close();
System.out.println(sb.toString());
System.exit(0);
}
}