A thread can enter the waiting state by invoking its sleep() method, by blocking on I/O, by unsuccessfully attempting to acquire an object’s lock, or by invoking an object’s wait() method. It can also enter the waiting state by invoking its (deprecated) suspend() method.
In Core Java, a thread can enter the waiting state in three main ways:
- By invoking
Object.wait()method:- A thread can voluntarily enter the waiting state by calling the
wait()method on an object. This method is used for inter-thread communication and synchronization.
javasynchronized (sharedObject) {
sharedObject.wait();
}
- A thread can voluntarily enter the waiting state by calling the
- By invoking
Thread.sleep(long milliseconds)method:- A thread can enter the waiting state by calling the
sleep()method, which causes the thread to pause for a specified amount of time. During this time, the thread is not actively executing.
javatry {
Thread.sleep(1000); // sleeps for 1 second
} catch (InterruptedException e) {
// Handle interruption exception
}
- A thread can enter the waiting state by calling the
- By blocking on I/O:
- A thread can enter the waiting state when it is waiting for an input/output operation to complete, such as reading from a file or waiting for data from a network socket.
javaInputStream inputStream = new FileInputStream("file.txt");
int data = inputStream.read(); // Thread may block waiting for data
These are three common ways in which a thread can enter the waiting state in Core Java. It’s important to note that a thread in the waiting state can be later awakened or interrupted to resume its execution.