Question

java多线程编程

请写一个JAVA启动类作为主线程，并完成以下功能：
A. 在启动类中创建并运行一个新的线程；
B. 在该新线程中从键盘读入一行字符串；
C. 当读入的字符串为“EXIT”时退出线程；
D. 否则将该值传递给主线程，由主线程将字符串打印出来。
E. 循环B、C和D的步骤直至程序退出

Answer 1

import java.util.Scanner;

public class Test
{
public static void main(String[] args)
{
final Message message = new Message();

final Thread thread = new Thread(new Runnable() {
public void run() {
Scanner scanner = new Scanner(System.in);
while (true) {
String msg = scanner.next();
if (msg.equals("EXIT"))
return;
message.sendMessage(msg);
}
}
});
thread.start();

while (true) {
if (thread.isAlive() == false)
break;
String msg = message.receiveMessage();
if (msg != null) {
System.out.println(msg);
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {}
}

}
}

class Message {
private String message;
private boolean unread = false;
synchronized void sendMessage(String message) {
this.message = message;
unread = true;
}

synchronized String receiveMessage() {
String msg = unread ? message : null;
unread = false;
return msg;
}
}