奇偶交叉打印

class EvenOddPrinter {
    public static void main(String[] args) throws Exception {
        R r = new R();
        new Thread("偶数线程") {
            @Override
            public void run() {
                while (r.v < 100) {
                    try {
                        r.printOdd();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
        new Thread("奇数线程") {
            @Override
            public void run() {
                while (r.v < 100) {
                    try {
                        r.printEven();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        }.start();
    }
    static class R {
        private int    v    = 0;
        private Object lock = new Object();
        synchronized void printEven() throws Exception {
            if (v % 2 != 0) {
                System.out.println(Thread.currentThread().getName() + ":" + v++);
                notifyAll();
                wait();
            }
        }
        synchronized void printOdd() throws Exception {
            if (v % 2 == 0) {
                System.out.println(Thread.currentThread().getName() + ":" + v++);
                notifyAll();
                wait();
            }
        }
    }
}