Introduction
Applications must manage several tasks at once in the fast-paced digital environment of today to guarantee efficiency and responsiveness. Java’s multithreading feature enables programmers to run numerous threads at once, increasing the speed and effectiveness of applications.
In this manual, we will look at:
- The definition of multithreading and its significance
- How multithreading is implemented in Java
- Thread states and lifecycle
- Thread safety and synchronization
- The best ways to use Java multithreading
You can also read for :-Is Java or Python Better for Full-Stack Development?
What is Multithreading?
Java’s multithreading functionality lets an application operate several threads simultaneously. Lightweight subprocesses that run independently yet share resources with other threads are called threads.
Multithreading advantages include:
- Enhanced Efficiency: The ability to run many threads concurrently results in a speedier application.
- Better Use of Resources: Threads effectively share system resources and memory.
- Better Responsiveness: UI programs maintain their responsiveness even when they are executing background operations.
- CPU Utilization Efficiency: A number of CPU cores are used efficiently.
Implementing Multithreading in Java
There are two primary ways to create threads in Java:
1. Extending the Thread Class
class MyThread extends Thread {
public void run() {
for (int i = 1; i <= 5; i++) {
System.out.println(Thread.currentThread().getName() + " - Count: " + i);
}
}
}
public class ThreadExample {
public static void main(String[] args) {
MyThread t1 = new MyThread();
MyThread t2 = new MyThread();
t1.start();
t2.start();
}
}2. Implementing the Runnable Interface
class MyRunnable implements Runnable {
public void run() {
for (int i = 1; i <= 5; i++) {
System.out.println(Thread.currentThread().getName() + " - Count: " + i);
}
}
}
public class RunnableExample {
public static void main(String[] args) {
Thread t1 = new Thread(new MyRunnable());
Thread t2 = new Thread(new MyRunnable());
t1.start();
t2.start();
}
}Using Runnable is preferred as it allows extending other classes while still implementing multithreading.
Thread Lifecycle in Java
In Java, a thread experiences the following states:
There is a new thread, but it hasn’t started yet.
Runnable: The thread is ready to run but is awaiting CPU time.
Running: At this moment, the thread is active.
A thread that is waiting for a resource is said to be blocked.
Waiting: A thread never stops waiting for another thread to provide it a signal.
A thread that uses timed waiting waits for a set period of time.
Terminated: The thread is no longer active.
Synchronization in Multithreading
When multiple threads access shared resources, race conditions and inconsistencies may occur. Synchronization ensures only one thread accesses the resource at a time.
Using synchronized Keyword
class SharedResource {
synchronized void printNumbers(int n) {
for (int i = 1; i <= 5; i++) {
System.out.println(Thread.currentThread().getName() + " - " + (n * i));
}
}
}
class MyThread extends Thread {
SharedResource sr;
MyThread(SharedResource sr) {
this.sr = sr;
}
public void run() {
sr.printNumbers(5);
}
}
public class SyncExample {
public static void main(String[] args) {
SharedResource obj = new SharedResource();
MyThread t1 = new MyThread(obj);
MyThread t2 = new MyThread(obj);
t1.start();
t2.start();
}
}Using Lock from java.util.concurrent
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
class SharedResource {
private final Lock lock = new ReentrantLock();
void printNumbers(int n) {
lock.lock();
try {
for (int i = 1; i <= 5; i++) {
System.out.println(Thread.currentThread().getName() + " - " + (n * i));
}
} finally {
lock.unlock();
}
}
}Best Practices for Multithreading in Java
Minimize Shared Resources: To prevent race circumstances, cut down on the number of shared variables.
- Use Thread Pools: Use ExecutorService to create numerous threads rather than doing it by hand.
- Make sure the resource locking order is correct to prevent deadlocks.
- Choose Runnable Over Thread Class: Encourages greater flexibility and design.
- Use Concurrent Collections: For thread safety, use ConcurrentHashMap and CopyOnWriteArrayList.
- Limit Thread Creation: Having too many threads can actually make performance worse.
Conclusion
Java multithreading is a potent technique that makes it possible to carry out activities in parallel effectively, enhancing responsiveness and performance. With Java’s built-in concurrency tools, synchronizing shared resources, and adhering to best practices, you can confidently create high-performance multithreaded applications..
Blackbox AI in Action: What You Need to Know
Node.js Streams: The Ultimate Guide to Handling Large Data
WhatsApp us