两个线程分别打印 1- 100，A 打印偶数， B打印奇数

package com.demo.thread;

public class PrintNumber {
    private static Object lock = new Object();
    private static int i = 1;
    private static int wait = 1;
    private static final int TOTAL = 100;

    public static void main(String[] args) {
        Thread thread1 = new Thread() {
            public void run() {
                while (i <= TOTAL) {
                    synchronized (lock) {
                        if (i % 2 == 1) {
                            System.out.println("thread1 " + i++);
                        } else {
                            lock.notify();
                            try {
                                lock.wait(wait);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
        };

        Thread thread2 = new Thread() {
            public void run() {
                while (i <= TOTAL) {
                    synchronized (lock) {
                        if (i % 2 == 0) {
                            System.out.println("thread2 " + i++);
                        } else {
                            lock.notify();
                            try {
                                lock.wait(wait);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
        };
        thread1.start();
        thread2.start();
    }
}

package com.demo.thread;

public class PrintNum {
    public static void main(String[] args) {
        for (int i = 1; i <= 100; ++i) {
            PrintOddThread printOddThread = new PrintOddThread(i);
            PrintEvenThread printEvenThread = new PrintEvenThread(i);
            Thread thread1 = new Thread(printOddThread);
            Thread thread2 = new Thread(printEvenThread);
            thread1.start();
            thread2.start();
        }
    }
}

class PrintOddThread implements Runnable {
    private int i;

    public PrintOddThread(int i) {
        this.i = i;
    }

    public void run() {
        if (i % 2 == 1) {
            System.out.println("thread1 " + i);
        }
    }
}

class PrintEvenThread implements Runnable {
    private int i;

    public PrintEvenThread(int i) {
        this.i = i;
    }

    public void run() {
        if (i % 2 == 0) {
            System.out.println("thread2 " + i);
        }
    }
}