ThreadedStringBufferTest

public class ThreadedStringBufferTest extends Thread {

    private static final String LINE_SEPARATOR = System.getProperty("line.separator");
    private static final StringBuffer sharedStringBuffer = new StringBuffer();

    private final String _name;
    private int _counter = 0;

    public ThreadedStringBufferTest(final String name) {
        _name = name;
    }

    public static void main(String[] args) {
        final String[] names = {"Able", "Bob", "Chris", "Don", "Ed"};
        final Thread[] threads = new Thread[names.length];
        for (int idx = 0; idx < names.length; ++idx) {
            threads[idx] = new ThreadedStringBufferTest(names[idx]);
        }

        final boolean threading = true;  // Set 'true' for the real test.

        if (threading) {
            // This is the multi-threaded path through the program:
            for (Thread thread : threads) {
                thread.start();
            }
            for (Thread thread : threads) {
                try {
                    thread.join();
                } catch (InterruptedException ex) {
                    // "carelessly" discard the exception here
                }
            }
        } else {
            // This is single-threaded, for comparison:
            for (Thread thread : threads) {
                thread.run();
            }
        }

        System.out.println("Final Result:");
        System.out.println(sharedStringBuffer.toString());
        System.out.println("[end]");
    }

    @Override
    public void run() {
        for (int counter = 1; counter <= 5; ++ counter) {
            sharedStringBuffer.append("Hello World!")
                    .append("  For my friend ").append(_name).append(" in particular.")
                    .append("  This is message #").append(++_counter).append('.')
                    .append(LINE_SEPARATOR);
        }
    }

}