import java.util.Arrays;
import java.io.Console;

/**
 * Simple interactive console application.
 * Uses the java.io.Console class of Java 6.
 */
public final class Console6 {

    public static final void main(String... aArgs){
        Console console = System.console();
        //read user name, using java.util.Formatter syntax :
        String username = console.readLine("User Name? ");

        //read the password, without echoing the output
        char[] password = console.readPassword("Password? ");

        //verify user name and password using some mechanism (elided)

        //the javadoc for the Console class recommends "zeroing-out" the password
        //when finished verifying it :
        Arrays.fill(password, ' ');

        console.printf("Welcome, %1$s.", username);
        console.printf(fNEW_LINE);

        String className = console.readLine("Please enter a package-qualified class name:");
        Class theClass = null;
        try {
            theClass = Class.forName(className);
            console.printf("The inheritance tree: %1$s", getInheritanceTree(theClass));
        }
        catch(ClassNotFoundException ex){
            console.printf("Cannot find that class.");
        }

        //this version just exits, without asking the user for more input
        console.printf("Bye.");
    }

    // PRIVATE
    private static final String fNEW_LINE = System.getProperty("line.separator");

    private static String getInheritanceTree(Class aClass){
        StringBuilder superclasses = new StringBuilder();
        superclasses.append(fNEW_LINE);
        Class theClass = aClass;
        while (theClass != null) {
            superclasses.append(theClass);
            superclasses.append(fNEW_LINE);
            theClass = theClass.getSuperclass();
        }
        superclasses.append(fNEW_LINE);
        return superclasses.toString();
    }
}