U4.java

import java.net.*;
import java.io.*;
import java.util.*; // for Map, Iterator, etc.

/**
Simple demonstration of URLConnection.
*/
public class U4
{
    public static void main(String argv[])
    {
        String query;
        URL url;
        URLConnection conn;
        InputStream in;
        BufferedReader reader;
        String line;
        Set headers;
        Iterator iter;

        try {
            // Step 1: Get a URLConnection.
            query = "http://leipold/03f/answers/hw07/hw07_code.html";
            url = new URL(query);
            conn = url.openConnection();

            // Step 2: Set its request properties.
            conn.setDoInput(true);

            // Step 3: Connect to the remote resource.
            conn.connect();

            // Step 4: Examine returned header information.
            System.out.println("Headers:");
            headers = conn.getHeaderFields().entrySet();
            iter = headers.iterator();
            while (iter.hasNext()) {
                Map.Entry z = (Map.Entry)(iter.next());
                System.out.println("   " + 
                    z.getKey() + " = " + z.getValue());
                }
            System.out.println();

            // Step 5: Read the resource data.
            in = conn.getInputStream();
            reader = new BufferedReader(new InputStreamReader(in));
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
                }
            reader.close();
            }
        catch (IOException e) {
            e.printStackTrace();
            }
    }
}