Skip to content

singlethread

Directory actions

More options

Directory actions

More options

Latest commit

 

History

History

singlethread

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
PrintTask.java
PrintTask.java
 
 
TestSignleThread.java
TestSignleThread.java
 
 
readme.md
readme.md
 
 

readme.md

☕ Java Lesson – Single Thread Executor in Java

Is lesson me hum seekhenge:

  • Single Thread Executor kya hota hai
  • Kaise kaam karta hai
  • Sequential execution
  • Examples with Runnable & Callable
  • Use cases

1️⃣ Single Thread Executor Kya Hota Hai?

Single Thread Executor:

sirf ek hi thread use karta hai sabhi tasks execute karne ke liye

2️⃣ Creation

ExecutorService executor = Executors.newSingleThreadExecutor();

3️⃣ Working

Tasks → Queue → Single Thread → Execution (one by one)

✔ ek time par ek hi task run karega
✔ next task wait karega

4️⃣ Basic Example (Runnable)

import java.util.concurrent.*;

class Test {

    public static void main(String[] args){

        ExecutorService executor = Executors.newSingleThreadExecutor();

        executor.execute(() -> {
            System.out.println("Task 1");
        });

        executor.execute(() -> {
            System.out.println("Task 2");
        });

        executor.execute(() -> {
            System.out.println("Task 3");
        });

        executor.shutdown();
    }
}

Output:

Task 1
Task 2
Task 3

5️⃣ Important Behavior

✔ tasks order maintain hota hai
✔ FIFO follow hota hai

6️⃣ Example with Delay

executor.execute(() -> {
    try {
        Thread.sleep(1000);
    } catch(Exception e){}

    System.out.println("Delayed Task");
});

7️⃣ Callable + Future Example

import java.util.concurrent.*;

class Test {

    public static void main(String[] args) throws Exception {

        ExecutorService executor = Executors.newSingleThreadExecutor();

        Callable<Integer> task = () -> {
            return 100;
        };

        Future<Integer> future = executor.submit(task);

        System.out.println(future.get());

        executor.shutdown();
    }
}

8️⃣ Why Use Single Thread Executor?

✔ thread creation avoid karta hai
✔ sequential processing
✔ thread safety without synchronization

9️⃣ Real-Life Use Case

Database operations
File writing
Logging system

👉 jahan order important ho

🔟 Advantages

✔ simple aur predictable
✔ race condition avoid hoti hai
✔ easy debugging

1️⃣1️⃣ Disadvantages

❌ parallel execution nahi hota
❌ slow for heavy tasks

1️⃣2️⃣ Important Points

✔ ek hi thread reuse hota hai
✔ tasks queue me wait karte hain
✔ always shutdown executor

🎯 Interview Questions

  1. Single Thread Executor kya hota hai?
  2. kya ye FIFO follow karta hai?
  3. isme race condition kyun nahi hoti?
  4. kab use karte hain?

🧾 Lesson Summary

Is lesson me humne seekha:

✔ Single Thread Executor concept
✔ Sequential execution
✔ Runnable & Callable usage
✔ Advantages aur use cases

Single Thread Executor Java me safe aur ordered task execution ke liye best hai.