1、wait 的用法
/**
* Causes the current thread to wait until another thread invokes the * {@link java.lang.Object#notify()} method or the
* {@link java.lang.Object#notifyAll()} method for this object.
* In other words, this method behaves exactly as if it simply * performs the call {@code wait(0)}.
* <p>
* The current thread must own this object's monitor. The thread
* releases ownership of this monitor and waits until another thread * notifies threads waiting on this object's monitor to wake up * either through a call to the {@code notify} method or the
* {@code notifyAll} method. The thread then waits until it can
* re-obtain ownership of the monitor and resumes execution. * <p>
* As in the one argument version, interrupts and spurious wakeups are
* possible, and this method should always be used in a loop: * <pre>
* synchronized (obj) {* while (<condition does not hold>)
* obj.wait(); * ... // Perform action appropriate to condition *} * </pre>
* This method should only be called by a thread that is the owner
* of this object's monitor. See the {@code notify} method for a
* description of the ways in which a thread can become the owner of * a monitor. * * @throws IllegalMonitorStateException if the current thread is not
* the owner of the object's monitor. * @throws InterruptedException if any thread interrupted the
* current thread before or while the current thread * was waiting for a notification. The <i>interrupted
* status</i> of the current thread is cleared when
* this exception is thrown. * @see java.lang.Object#notify()
* @see java.lang.Object#notifyAll()
*/
public final void wait() throws InterruptedException {wait(0);
}- 参考 wait 的注解，当调用 wait 的时候必须要持有监视器锁，不然会跑出非法监视器异样
为什么 wait() 和 notify() 须要搭配 synchonized 关键字应用
2 sleep
/**
* Causes the currently executing thread to sleep (temporarily cease * execution) for the specified number of milliseconds, subject to * the precision and accuracy of system timers and schedulers. The thread * does not lose ownership of any monitors. * * @param millis
* the length of time to sleep in milliseconds
* * @throws IllegalArgumentException
* if the value of {@code millis} is negative
* * @throws InterruptedException
* if any thread has interrupted the current thread. The * <i>interrupted status</i> of the current thread is
* cleared when this exception is thrown.
*/
public static native void sleep(long millis) throws InterruptedException;