迅雷笔试题 （JAVA多线程）启动三个线程，分别打印A B C，现在写一个程序 循环打印ABCABCABC

题目：http://wenku.baidu.com/view/d66187aad1f34693daef3e8a.html

启动三个线程，分别打印A B C，现在写一个程序 循环打印ABCABCABC....

本文分别使用wait、nofity和Semaphore来实现：

wait、nofity版本

public class TestThread {

    public static void main(String[] args) {

        new Thread(new OrderThread(0,'A')).start();

        new Thread(new OrderThread(1,'B')).start();

        new Thread(new OrderThread(2,'C')).start();

    }

}

class OrderThread implements Runnable {

    //定义一个类静态变量的锁对象

    private static Object o = new Object();

    //类静态变量、用来记录是哪个线程进入运行

    private static int count = 0;

    //每个线程的标识，名称

    private char ID;

    //用来控制是线程运行的标识

    private int id;

    //每个线程运行的次数

    private int num = 0;

    public OrderThread(int id,char ID) {

        this.id = id;

        this.ID = ID;

    }

    public void run() {

        synchronized (o) {

            while (num < 10) {

                if(count % 3 == id){

                    System.out.print(ID);

                    ++ count;

                    ++ num;

                    o.notifyAll();

                }

                else{

                    try {

                        o.wait();

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    }

                }

            }

        }

    }

}

Semaphore版本

public class ThreadSync {

    static class ConditionThread extends Thread {

        private Semaphore preCond;

        private Semaphore postCond;

        ConditionThread(Semaphore preCond, Semaphore postCond, String name) {

            this.preCond = preCond;

            this.postCond = postCond;

            this.setName(name);

        }

        public void run() {

            for (int i = 0; i < 10; i++) {

                try {

                    preCond.acquire();

                    System.out.print(Thread.currentThread().getName());

                    postCond.release();

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        }

    }

    public static void main(String[] args) throws InterruptedException {

        Semaphore semaphoreA = new Semaphore(0);

        Semaphore semaphoreB = new Semaphore(0);

        Semaphore semaphoreC = new Semaphore(1);

        Thread threadA = new ConditionThread(semaphoreC, semaphoreA, "A");

        Thread threadB = new ConditionThread(semaphoreA, semaphoreB, "B");

        Thread threadC = new ConditionThread(semaphoreB, semaphoreC, "C");

        threadA.start();

        threadB.start();

        threadC.start();

        // threadA.join();

        // threadB.join();

        // threadC.join();

    }

}

2，假如有字符串“6sabcsssfsfs33” ，用最有快速的方法去掉字符“ab3”，不能用java内置字符串方法（indeOf,substring,replaceAll等）

package com.kingdee.al;

public class Test {

    public static void main(String[] args) {

        String str = "6sabcsssfsfs33";

        char[] array = { 'a', 'b', '3' };

        char[] newArray = str.toCharArray();

        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < newArray.length; i++) {

            boolean isMatch = false;

            for (char key : array){

                if (newArray[i] == key)

                    isMatch = true;

            }

            if(!isMatch){

                sb.append(newArray[i]);

            }

        }

        System.out.println(sb.toString());

    }

}

迅雷笔试题 （JAVA多线程）启动三个线程，分别打印A B C，现在写一个程序 循环打印ABCABCABC的相关教程结束。