blocks|key|1436107|text|wait是在Object中定义的，而不是Thread。Thread上的监视器有点不可预测。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1436108|尽管所有Java对象都有监视器，但通常最好使用专用锁：|1436109|private+final+Object+lock+=+new+Object();|code-block|syntax|javascript|1436110|通过使用命名类，您可以以较小的内存成本(每个进程大约2K+)更容易地读取诊断信息：|1436111|private+static+final+class+Lock+{+}
private+final+Object+lock+=+new+Lock();|1436112|为了对对象执行wait或notify/notifyAll操作，您需要使用synchronized语句持有锁。此外，您还需要一个while循环来检查唤醒条件(找到一个关于线程的很好的文本来解释原因)。|1436113|synchronized+(lock)+{
++++while+(!isWakeupNeeded())+{
++++++++lock.wait();
++++}
}|1436114|要通知，请执行以下操作：|1436115|synchronized+(lock)+{
++++makeWakeupNeeded();
++++lock.notifyAll();
}|1436116|在进行多线程时，理解Java语言和java.util.concurrent.locks锁(以及java.util.concurrent.atomic)是非常有必要的。但只要有可能，就使用java.util.concurrent数据结构。|1436117|entityMap^0|0|4|6|6|K|6|R|6|0|0|0|0|0|7|4|C|6|J|9|10|C|1R|5|0|0|0|0|H|Q|1B|R|2L|K|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1B|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1C|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1D|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1E|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]]|D|@]|E|$]]|$1|S|3|T|5|J|7|1Q|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|1R|8|@]|D|@]|E|$]]|$1|W|3|X|5|J|7|1S|8|@]|D|@]|E|$K|L]]|$1|Y|3|Z|5|6|7|1T|8|@$9|1U|A|1V|B|C]|$9|1W|A|1X|B|C]|$9|1Y|A|1Z|B|C]]|D|@]|E|$]]|$1|10|3|-4|5|6|7|20|8|@]|D|@]|E|$]]]|11|$]]

<code>wait</code> is defined in <code>Object</code>, and not it <code>Thread</code>. The monitor on <code>Thread</code> is a little unpredictable.

Although all Java objects have monitors, it is generally better to have a dedicated lock:

<pre><code>private final Object lock = new Object();
</code></pre>

You can get slightly easier to read diagnostics, at a small memory cost (about 2K per process) by using a named class:

<pre><code>private static final class Lock { }
private final Object lock = new Lock();
</code></pre>

In order to <code>wait</code> or <code>notify</code>/<code>notifyAll</code> an object, you need to be holding the lock with the <code>synchronized</code> statement. Also, you will need a <code>while</code> loop to check for the wakeup condition (find a good text on threading to explain why).

<pre><code>synchronized (lock) {
 while (!isWakeupNeeded()) {
 lock.wait();
 }
}
</code></pre>

To notify:

<pre><code>synchronized (lock) {
 makeWakeupNeeded();
 lock.notifyAll();
}
</code></pre>

It is well worth getting to understand both Java language and <code>java.util.concurrent.locks</code> locks (and <code>java.util.concurrent.atomic</code>) when getting into multithreading. But use <code>java.util.concurrent</code> data structures whenever you can.

blocks|key|1221176|text|我不确定这是否会帮助其他人，但这是解决我在用户"Tom+Hawtin+-tacklin“上面的回答中问题的关键部分：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1221177|synchronized+(lock)+{
++++makeWakeupNeeded();
++++lock.notifyAll();
}|code-block|syntax|javascript|1221178|"lock“在synchronized()中作为参数传递，它也在”lock“.notifyAll()中使用；|1221179|一旦我在这两个地方成功了，我就让它工作了。|1221180|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Not sure if this will help somebody else out or not but this was the key part to fix my problem in user "Tom Hawtin - tacklin"'s answer above:

<pre><code>synchronized (lock) {
 makeWakeupNeeded();
 lock.notifyAll();
}
</code></pre>

Just the fact that the "lock" is passed as an argument in synchronized() and it is also used in "lock".notifyAll();

Once I made it in those 2 places I got it working

blocks|key|1221231|text|那些使用Java+7.0或更低版本的人可以参考我在这里使用的代码，它可以工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1221232|public+class+WaitTest+{

++++private+final+Lock+lock+=+new+ReentrantLock();
++++private+final+Condition+condition+=+lock.newCondition();

++++public+void+waitHere(long+waitTime)+{
++++++++System.out.println("wait+started...");
++++++++lock.lock();
++++++++try+{
++++++++++++condition.await(waitTime,+TimeUnit.SECONDS);
++++++++}+catch+(InterruptedException+e)+{
++++++++++++//+TODO+Auto-generated+catch+block
++++++++++++e.printStackTrace();
++++++++}
++++++++lock.unlock();
++++++++System.out.println("wait+ends+here...");
++++}

++++public+static+void+main(String[]+args)+{
++++++++//Your+Code
++++++++new+WaitTest().waitHere(10);
++++++++//Your+Code
++++}

}|code-block|syntax|javascript|1221233|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Those who are using Java 7.0 or below version can refer the code which I used here and it works.

<pre><code>public class WaitTest {

 private final Lock lock = new ReentrantLock();
 private final Condition condition = lock.newCondition();

 public void waitHere(long waitTime) {
 System.out.println("wait started...");
 lock.lock();
 try {
 condition.await(waitTime, TimeUnit.SECONDS);
 } catch (InterruptedException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 lock.unlock();
 System.out.println("wait ends here...");
 }

 public static void main(String[] args) {
 //Your Code
 new WaitTest().waitHere(10);
 //Your Code
 }

}
</code></pre>

blocks|key|1221269|text|为了在对象上调用wait()/notify()，它需要在synchronized块内。所以首先你必须锁定对象，然后才能调用这些函数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1221270|synchronized(obj)
{
+++obj.wait()
}|code-block|syntax|javascript|1221271|详细解释请访问：https://dzone.com/articles/multithreading-java-and-interviewspart-2|offset|length|1221272|entityMap|0|LINK|mutability|MUTABLE|url|https://dzone.com/articles/multithreading-java-and-interviewspart-2^0|0|0|8|1V|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

For calling wait()/notify() on object, it needs to be inside synchronized block. So first you have to take lock on object then would be possible to call these function.
<pre><code>synchronized(obj)
{
 obj.wait()
}
</code></pre>
For detailed explanation:
<a href="https://dzone.com/articles/multithreading-java-and-interviewspart-2" rel="nofollow noreferrer">https://dzone.com/articles/multithreading-java-and-interviewspart-2</a>

I am using multi-threading in java for my program.
I have run thread successfully but when I am using <code>Thread.wait()</code>, it is throwing <code>java.lang.IllegalMonitorStateException</code>.
How can I make a thread wait until it will be notified?

IllegalMonitorStateException on wait() call

我在我的程序中使用了java中的多线程。我已经成功地运行了线程，但是当我使用Thread.wait()时，它抛出了java.lang.IllegalMonitorStateException。我如何让一个线程等待，直到它被通知？

问等待()调用时的IllegalMonitorStateException
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