Synchronized Java

Synchronized Java

I'm happy to respond in English only! Here's a detailed answer about synchronized Java:

Synchronization is an essential concept in multithreaded programming, and it plays a crucial role in ensuring the consistency and integrity of shared resources in concurrent systems.

In Java, synchronization is achieved using the keyword synchronized. This keyword is used with methods or blocks of code to ensure that only one thread can execute them at a time. When a thread attempts to enter a synchronized block or method, it must first acquire a lock on an object (known as the monitor). If another thread already holds this lock, the requesting thread will be forced to wait until the lock is released.

Here are some key aspects of synchronization in Java:

Benefits of Synchronization in Java:

Common scenarios where synchronization is used in Java:

Best Practices for Using Synchronization in Java:

By understanding how to use synchronization effectively in Java, developers can create more robust, scalable, and thread-safe applications that handle concurrent execution with ease.

Java synchronized keyword example

The synchronized keyword is a fundamental concept in Java that allows multiple threads to share the same resource safely. It's used to ensure that only one thread can access a specific block of code at a time, preventing conflicts and ensuring data consistency.

Let's dive into an example:

Suppose we have a simple banking system with multiple users accessing their accounts simultaneously. Each user wants to withdraw money from their account, but we need to ensure that the withdrawal process is atomic, meaning it either succeeds or fails entirely. We can achieve this using the synchronized keyword.

Here's the code:

class BankAccount {
private int balance;
public BankAccount(int initialBalance) {
balance = initialBalance;
}
public synchronized void withdraw(int amount) {
if (amount > 0 && balance >= amount) {
balance -= amount;
System.out.println("Withdrawal successful! New balance: " + balance);
} else {
System.out.println("Insufficient funds or invalid withdrawal amount.");
}
}
}
class UserThread extends Thread {
private BankAccount account;
private int amount;
public UserThread(BankAccount account, int amount) {
this.account = account;
this.amount = amount;
}
@Override
public void run() {
try {
Thread.sleep((int) (Math.random() * 1000)); // Simulate some delay
} catch (InterruptedException e) {
// Handle the exception
}
account.withdraw(amount);
}
}
public class SynchronizedExample {
public static void main(String[] args) {
BankAccount account = new BankAccount(1000); // Initial balance is java000
UserThread t1 = new UserThread(account, 200);
UserThread t2 = new UserThread(account, 300);
UserThread t3 = new UserThread(account, 400);
t1.start();
t2.start();
t3.start();
// Wait for all threads to finish
try {
Thread.sleep((int) (Math.random() * 2000)); // Simulate some delay
} catch (InterruptedException e) {
// Handle the exception
}
}
}

In this example, we have a BankAccount class with a withdraw method that is synchronized. This means that only one thread can execute this method at a time.

We then create multiple user threads (UserThread) that withdraw money from the account. Each thread simulates some delay before withdrawing the funds. The synchronized keyword ensures that only one withdrawal operation can be executed at a time, preventing conflicts and ensuring data consistency.

When you run the program, you'll see that each withdrawal operation is atomic and doesn't interfere with other threads' actions. This is because the synchronized method ensures that only one thread can access the critical section of code (i.e., the withdrawal logic) at a time.

In this example, we've demonstrated how the synchronized keyword can be used to ensure thread safety in Java. This is just one of many scenarios where synchronization plays a crucial role in ensuring data consistency and preventing conflicts between multiple threads.