现在我正在努力完成标题中的任务。我创建了X个线程,每个线程在周期中Z次打印Y个相等的数字(从构造函数中获取,例如" 11111"," 222222"等)。结果如下:
111111111
222222222
333333333
111111111
222222222
333333333
对于X = 3,Y = 9且Z = 2。 首先,我使用睡眠,中断和传递解决了这个问题" next"线程到前一个的构造函数。一个中断另一个等。下一步是使用wait / notify而不是sleep和interrupt来获得相同的输出。据我所见,创建共享监视器对象,在每次打印之后以及在某个时刻调用等待都是必要的。我应该调用notifyAll。 目前的代码是:
public class PrinterController {
private static final int THREADS_NUMBER = 5;
public static void main(String[] args) {
Printer[] printers = new Printer[THREADS_NUMBER];
for (int i = 0; i < THREADS_NUMBER; i++) {
printers[i] = new Printer(i);
printers[i].start();
}
}
}
public class Printer extends Thread {
private static int portion = 10;
private static int totalNumber = 100;
private int digit;
private static final Object monitor = new Object();
public Printer(int digit) {
this.digit = digit;
}
@Override
public void run() {
synchronized (monitor) {
int portionsNumber = totalNumber / portion;
for (int i = 0; i < portionsNumber; i++) {
printLine();
try {
monitor.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
private void printLine() {
for (int j = 0; j < portion; j++) {
System.out.print(digit);
}
System.out.println();
}
}
你能帮助改善它吗?我发现了类似的任务,但他们没有包含适当的答案。感谢。
最终解决方案基于纳迪尔的答案:
public class Printer extends Thread {
private static int portion = 10;
private static int totalNumber = 100;
private int digit;
static Object monitor = new Object();
static Integer counter = 0;
public Printer(int digit) {
this.digit = digit;
}
@Override
public void run() {
int portionsNumber = totalNumber / portion;
for (int i = 0; i < portionsNumber; i++) {
synchronized (monitor) {
while (digit != counter) {
try {
monitor.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
printLine();
monitor.notifyAll();
}
}
}
private void printLine() {
for (int j = 0; j < portion; j++) {
System.out.print(digit);
}
System.out.println();
counter = (counter + 1) % PrinterController.THREADS_NUMBER;
}
}
答案 0 :(得分:3)
可以使用用于同步线程的类来完成(甚至确保它们是orderer)。所有线程都将共享同一个实例。
public class Synchronizer
{
private int nextThread;
private int maxNumThreads;
public Synchronizer(int numThreads)
{
maxNumThreads = numThreads;
nextThread = 0;
}
public void doSync(int threadId) throws Exception
{
synchronized(this)
{
while(nextThread != threadId)
{
wait();
}
}
}
public void threadDone(int threadId) throws Exception
{
synchronized(this)
{
nextThread = (threadId + 1) % maxNumThreads;
notifyAll();
}
}
}
在您的主题run()
上,您可以在打印任何内容之前致电doSync()
。然后你会把代码放到打印中,然后你会调用threadDone()
,允许下一个线程被释放。 id用于强制执行订单。