Design patterns are reusable solutions to common problems that occur in software design. They represent best practices evolved over time by experienced developers. Understanding these patterns helps you write more maintainable and flexible code.
Types of Design Patterns:
- Creational Patterns: These patterns focus on object creation mechanisms. Examples include:
- Singleton: Ensures a class has only one instance and provides a global point of access to it
- Factory Method: Creates objects without specifying the exact class of object that will be created
- Builder: Separates the construction of complex objects from their representation
- Structural Patterns: These patterns focus on composition of classes or objects. Examples include:
- Adapter: Allows incompatible interfaces to work together
- Decorator: Attaches additional responsibilities to objects dynamically
- Facade: Provides a simplified interface to a complex subsystem
- Behavioral Patterns: These patterns focus on communication between objects. Examples include:
- Observer: Defines a one-to-many dependency between objects
- Strategy: Defines a family of algorithms and makes them interchangeable
- Command: Encapsulates a request as an object
Remote Debugging Concepts:
Remote debugging is an essential skill when working with distributed systems or services running in different environments:
- To debug a remote process, the JVM must be started with debugging options enabled
- The IDE connects to this process over a network socket
- Remote debugging is necessary when:
- The application runs in a different environment (e.g., production, staging)
- Working with distributed systems where components run on different machines
- Debugging applications inside containers or cloud environments
- Sample code to attach a debugger:
// JVM startup parameters
-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005
// In IntelliJ IDEA: Run > Attach to Process
// In Eclipse: Run > Debug Configurations > Remote Java Application