source: trunk/JavaHelperLib/src/de/ugoe/cs/util/console/TextConsole.java @ 185

package de.ugoe.cs.util.console;

import java.io.IOException;

/**
 * <p>
 * Implements a simple console observer that prints normal text to
 * {@code stdout}, errors to {@code stderr} and reads from {@code stdin}.
 * </p>
 * 
 * @author Steffen Herbold
 * @version 1.0
 */
public class TextConsole implements ConsoleObserver {

        /**
         * <p>
         * In the debug mode, trace messages will be printed.
         * </p>
         */
        private boolean debugMode = true;

        /**
         * <p>
         * Creates a new text console and automatically registers it as observer.
         * </p>
         */
        public TextConsole() {
                Console.getInstance().registerObserver(this);
        }

        /**
         * <p>
         * Prints messages to {@code stdout}.
         * </p>
         * 
         * @see ConsoleObserver#updateText(java.lang.String)
         */
        public void updateText(String newMessage) {
                System.out.print(newMessage);
        }

        /**
         * <p>
         * Prints messages to {@code stderr}.
         * </p>
         * 
         * @see ConsoleObserver#errStream(String)
         */
        @Override
        public void errStream(String errMessage) {
                System.err.print(errMessage);
        }

        /**
         * <p>
         * Prints the stacktrace of an exception to {@code stderr}.
         * </p>
         * 
         * @see ConsoleObserver#printStacktrace(Exception)
         */
        @Override
        public void printStacktrace(Exception e) {
                e.printStackTrace();
        }

        /**
         * <p>
         * Prints messages to {@code stdout}. These messages are only printed, if
         * the console is run in debug mode.
         * </p>
         */
        @Override
        public void trace(String traceMessage) {
                if (debugMode) {
                        System.out.print(traceMessage);
                }
        }

        /**
         * <p>
         * Starts a new TextConsole. If the text console is started, it can be used
         * not only to print message, but also to execute commands by reading
         * {@code stdin}.
         * </p>
         * 
         * @param debugMode
         *            true, if the application is to run in debug mode, i.e. trace
         *            messages will be printed
         */
        public void run(boolean debugMode) {
                this.debugMode = debugMode;
                CommandExecuter exec = CommandExecuter.getInstance();
                while (true) {
                        System.out.print("> ");
                        String command = getCommand().trim();
                        if (!command.equals("")) {
                                exec.exec(command);
                        }
                }
        }

        /**
         * <p>
         * Reads a new command from {@code stdin}.
         * </p>
         * 
         * @return a string with a command
         */
        protected String getCommand() {
                byte[] buffer = new byte[1024];
                try {
                        System.in.read(buffer);
                } catch (IOException e) {

                }
                return new String(buffer);
        }

        /**
         * <p>
         * The {@link TextConsole} ignores this notification.
         * </p>
         * 
         * @see de.ugoe.cs.util.console.ConsoleObserver#commandExecuted(java.lang.String)
         */
        @Override
        public void commandExecuted(String command) {
                // ignores the notification
        }
}