Advanced Topics in Java
1. Java Memory Management
Java memory management involves managing the memory used by Java
applications. The JVM (Java Virtual Machine) is responsible for memory
allocation and garbage collection.
Heap Memory: Used for dynamic memory allocation. Objects are created in
the heap.
Stack Memory: Used for method execution and local variables.
Garbage Collection: Automatic memory management to reclaim memory
used by objects that are no longer referenced. Java provides several
garbage collectors (e.g., G1, Serial GC).
Memory Leaks: Occur when objects are no longer needed but are still
referenced, preventing garbage collection.
2. Concurrency and Parallelism
Concurrency is the ability of a program to manage multiple tasks at the
same time, while parallelism is executing multiple tasks simultaneously
(usually on multiple cores).
Java provides several tools for working with concurrency:
o Threads: Execute code concurrently in a multi-threaded
environment.
o Executor Framework: Manages thread pools efficiently, providing
various types of thread executors.
o Locks and Synchronization: synchronized blocks and methods help
prevent race conditions. Java provides the ReentrantLock class for
more advanced locking.
o ForkJoinPool: A framework that divides tasks into smaller subtasks
and executes them in parallel.
o CompletableFuture: Provides a more flexible and functional
approach to handling asynchronous tasks.
, Example (ExecutorService):
ExecutorService executor = Executors.newFixedThreadPool(4);
executor.submit(() -> System.out.println("Task executed"));
executor.shutdown();
3. Java Generics
Generics allow you to write classes, interfaces, and methods that operate
on objects of various types while providing compile-time type safety.
Using generics, you can create more flexible and reusable code by defining
type parameters in classes or methods.
Example (Generics):
class Box<T> {
private T value;
public void setValue(T value) {
this.value = value;
}
public T getValue() {
return value;
}
}
public class Main {
public static void main(String[] args) {
Box<Integer> intBox = new Box<>();
intBox.setValue(100);
System.out.println(intBox.getValue());
}
}
1. Java Memory Management
Java memory management involves managing the memory used by Java
applications. The JVM (Java Virtual Machine) is responsible for memory
allocation and garbage collection.
Heap Memory: Used for dynamic memory allocation. Objects are created in
the heap.
Stack Memory: Used for method execution and local variables.
Garbage Collection: Automatic memory management to reclaim memory
used by objects that are no longer referenced. Java provides several
garbage collectors (e.g., G1, Serial GC).
Memory Leaks: Occur when objects are no longer needed but are still
referenced, preventing garbage collection.
2. Concurrency and Parallelism
Concurrency is the ability of a program to manage multiple tasks at the
same time, while parallelism is executing multiple tasks simultaneously
(usually on multiple cores).
Java provides several tools for working with concurrency:
o Threads: Execute code concurrently in a multi-threaded
environment.
o Executor Framework: Manages thread pools efficiently, providing
various types of thread executors.
o Locks and Synchronization: synchronized blocks and methods help
prevent race conditions. Java provides the ReentrantLock class for
more advanced locking.
o ForkJoinPool: A framework that divides tasks into smaller subtasks
and executes them in parallel.
o CompletableFuture: Provides a more flexible and functional
approach to handling asynchronous tasks.
, Example (ExecutorService):
ExecutorService executor = Executors.newFixedThreadPool(4);
executor.submit(() -> System.out.println("Task executed"));
executor.shutdown();
3. Java Generics
Generics allow you to write classes, interfaces, and methods that operate
on objects of various types while providing compile-time type safety.
Using generics, you can create more flexible and reusable code by defining
type parameters in classes or methods.
Example (Generics):
class Box<T> {
private T value;
public void setValue(T value) {
this.value = value;
}
public T getValue() {
return value;
}
}
public class Main {
public static void main(String[] args) {
Box<Integer> intBox = new Box<>();
intBox.setValue(100);
System.out.println(intBox.getValue());
}
}
