我有场景，我的一些调用10Thread秒，每个Thread都有等到Notifier类通知我要通知具体ThreadS，我做的是我使用HashMap与Threadid作为key和Thread实例作为值。后来Notifier我试图通过遍历map.get(threadId)给出Thread实例的地图来通知它，我试图调用通知但它正在抛出IllegalmonitorException. 我有疑问怎么是否同步HashMap或Thread在双方Waiter和Notifier类..
package com.cgi.sample.jms.requestor;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class RequestorApplication {
private final Object lock = new Object();
public static String correlationId;
public static String getCorrelationId() {
correlationId = UUID.randomUUID().toString();
return correlationId;
}
public static void main(String args[]) throws Exception {
Map<Long, Thread> map = new HashMap<Long, Thread>();
ExecutorService executor = Executors.newFixedThreadPool(5);
for (int i = 0; i < 2; i++) {
Waiter waiter = new Waiter(map);
executor.execute(waiter);
Notifier notifier = new Notifier(map);
executor.execute(notifier);
}
System.out.println("All the threads are started");
}
}
class Waiter implements Runnable {
Map<Long, Thread> map;
ExecutorService executor = Executors.newFixedThreadPool(5);
public Waiter(Map<Long, Thread> map) {
this.map = map;
}
public void run() {
ExecutorService executor = Executors.newFixedThreadPool(5);
for (int i = 0; i < 2; i++) {
Runner instance = new Runner();
System.out.println("Executing thread " + " with " + Thread.currentThread().getName());
long threadId = Thread.currentThread().getId();
String threadname = Thread.currentThread().getName();
executor.execute(instance);
synchronized (map) {
map.put(threadId, Thread.currentThread());
try {
instance.wait();
System.out.println(threadname + " Thread entered into waiting state!!!");
// Thread.currentThread().wait();
System.out.println(threadname + " Thread woke up from wait!!!!!");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
class Notifier implements Runnable {
Map<Long, Thread> map;
public Notifier(Map<Long, Thread> map)
{
this.map = map;
}
public synchronized void run() {
synchronized (map) {
for (Map.Entry<Long, Thread> entry : map.entrySet()) {
System.out.println("stored threads in map are--->" + map.get(entry.getKey()));
map.get(entry.getKey()).notify();
}
}
}
}
class Runner implements Runnable {
public void run() {
System.out.println("runner invoked");
}
}
您的问题的答案是：YES。因为线程是一个对象，它可以存储到 HashMap 中。
另外，@TJCrowder 告诉您，您使用通知的方式是错误的。这是因为您正在对没有 Thread ( map.get(entry.getKey()).notify();)锁定的对象调用通知。您应该调用拥有线程锁notify的对象Runner( instance.notify()) 的 ，而不是您的代码向我们展示的：instance.wait();
首先！您必须instance将块与将使用该wait方法阻止线程的对象同步，例如：
synchronized(instance){
try{
instance.wait()
}catch(...)
{
//Do Something else
}
}
并且，调用notify对象的方法Runner停止等待并继续线程并离开同步块，如下所示：
map.get(entry.getKey()).getRunnerInstance().notify();
但是，请考虑一下，使用您当前的代码很难实现此提示，因为您必须重写几个部分，例如：您使用处于 for 循环上下文中的对象来阻塞线程的代码。
for (int i = 0; i < 2; i++) {
Runner instance = new Runner();
//...
synchronized (map) {
map.put(threadId, Thread.currentThread());
try {
instance.wait(); //You are blocking over a instance declared into the For Loop.
}catch(..){
//..
};
}
}
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