The Java application written below uses regular expressions to find and display hyperlinks contained within a Web page. After compiling the file, you should save a Web page to the same folder that contains ShowLinks.class.

 import java.io.*;
import java.util.regex.*;

public class ShowLinks {
    public static void main(String[] arguments) {
        if (arguments.length < 1) {
            System.out.println("Usage: java ShowLinks [page]");
            System.exit(0);
        }
        String page = loadPage(arguments[0]);
        Pattern pattern = Pattern.compile("<a.+href=\"(.+?)\"");
        Matcher matcher = pattern.matcher(page);
        while (matcher.find()) {
            System.out.println( matcher.group(1));
        }
    }

    private static String loadPage(String name) {
        StringBuffer output = new StringBuffer();
        try {
            FileReader file = new FileReader(name);
            BufferedReader buff = new BufferedReader(file);
            boolean eof = false;
            while (!eof) {
                String line = buff.readLine();
                if (line == null)
                    eof = true;
                else
                    output.append(line + "\n");
            }
            buff.close();
        } catch (IOException e) {
            System.out.println("Error -- " + e.toString());
        }
        return output.toString();
    }
}