What is difference between executor submit () and executer execute () method in Java?

submit() and Executor. execute() methods in Java? A main difference between the submit() and execute() method is that ExecuterService. submit()can return result of computation because it has a return type of Future, but execute() method cannot return anything because it's return type is void.

Besides, what is difference between executor submit () and executer execute () methods?

The submit() can accept both Runnable and Callable task but execute() can only accept the Runnable task. The submit() method is declared in ExecutorService interface while execute() method is declared in the Executor interface.

One may also ask, what are executor and ExecutorService and what are the differences between them? The main difference between Executor, ExecutorService, and Executors class is that Executor is the core interface which is an abstraction for parallel execution. It separates task from execution, this is different from java. lang. Thread class which combines both task and its execution.

Correspondingly, what is the use of executors in Java?

The Java ExecutorService is a construct that allows you to pass a task to be executed by a thread asynchronously. The executor service creates and maintains a reusable pool of threads for executing submitted tasks.

What is ExecutorService executor?

Executor - A simple interface that contains a method called execute() to launch a task specified by a Runnable object. ExecutorService - A sub-interface of Executor that adds functionality to manage the lifecycle of the tasks.

32 Related Question Answers Found

Does invokeAll block?

Java's ExecutorService interface defines a method called invokeAll which takes in a Collection of Callable objects to be processed concurrently. However, the invokeAll method itself waits for all of the tasks to finish running before returning, making it a blocking method.

What is Java executor framework?

Java executor framework (java. util. concurrent. Executor), released with the JDK 5 is used to run the Runnable objects without creating new threads every time and mostly re-using the already created threads. Creating a thread in java is a very expensive process which includes memory overhead also.

What is callable interface?

Interface Callable<V>

Implementors define a single method with no arguments called call. The Callable interface is similar to Runnable , in that both are designed for classes whose instances are potentially executed by another thread. A Runnable, however, does not return a result and cannot throw a checked exception.

What is atomic operation in Java?

An atomic operation is an operation which is performed as a single unit of work without the possibility of interference from other operations. The Java language specification guarantees that reading or writing a variable is an atomic operation(unless the variable is of type long or double ).

What is future object in Java?

A Java Future, java. util. When the asynchronous task is created, a Java Future object is returned. This Future object functions as a handle to the result of the asynchronous task. Once the asynchronous task completes, the result can be accessed via the Future object returned when the task was started.

What is callable Java?

Callable , represents an asynchronous task which can be executed by a separate thread. For instance, it is possible to submit a Callable object to a Java ExecutorService which will then execute it asynchronously.

What is ThreadPoolExecutor in Java?

java. util. concurrent. ThreadPoolExecutor is an ExecutorService to execute each submitted task using one of possibly several pooled threads, normally configured using Executors factory methods. It also provides various utility methods to check current threads statistics and control them.

How do you use ExecutorService in Java?

First an ExecutorService is created using the Executors newFixedThreadPool() factory method. This creates a thread pool with 10 threads executing tasks. Second, an anonymous implementation of the Runnable interface is passed to the execute() method.

Is ExecutorService thread safe?

ExecutorService does not mandate or otherwise guarantee that all implementations are thread-safe, and it cannot as it is an interface. These types of contracts are outside of the scope of a Java interface. However, ThreadPoolExecutor both is and is clearly documented as being thread-safe.

What is multithreading framework?

Working with Java Executor framework in multithreaded application. It is the first concurrent utility framework in java and used for standardizing invocation, scheduling, execution and control of asynchronous tasks in parallel threads. The execution rules are defined during the creation of the constructor.

Do we need to shutdown ExecutorService?

When finished using an ExecutorService , you need to shut it down explicitly. From its javadoc: "An unused ExecutorService should be shut down to allow reclamation of its resources." Calling shutdown initiates a gradual and orderly shutdown.

What is LinkedBlockingQueue in Java?

LinkedBlockingQueue Class in Java. LinkedBlockingQueue is an optionally-bounded blocking queue based on linked nodes. It means that the LinkedBlockingQueue can be bounded, if its capacity is given, else the LinkedBlockingQueue will be unbounded. The tail of this queue is the newest element of the elements of this queue

How do I shut down ExecutorService?

To properly shut down an ExecutorService, we have the shutdown() and shutdownNow() APIs. The shutdown() method doesn't cause an immediate destruction of the ExecutorService. It will make the ExecutorService stop accepting new tasks and shut down after all running threads finish their current work.

What is BlockingQueue in Java?

java. util. concurrent. BlockingQueue is a java Queue that support operations that wait for the queue to become non-empty when retrieving and removing an element, and wait for space to become available in the queue when adding an element.

How can we avoid deadlock in Java?

How To Avoid Deadlock in Java?

Avoid Nested Locks – You must avoid giving locks to multiple threads, this is the main reason for a deadlock condition.
Avoid Unnecessary Locks – The locks should be given to the important threads.

What is a CountDownLatch?

As per java docs, CountDownLatch is a synchronization aid that allows one or more threads to wait until a set of operations being performed in other threads completes. CountDownLatch concept is very common interview question in java concurrency, so make sure you understand it well.

What is multithreading in Java?

Multithreading in Java is a process of executing multiple threads simultaneously. A thread is a lightweight sub-process, the smallest unit of processing. Multiprocessing and multithreading, both are used to achieve multitasking.