Difference between design pattern and architectural pattern.

Q1: What is a design pattern in Java?

...

Q2: Difference between design pattern and architectural pattern.

A design pattern refers to an established and verified solution for a repetitive issue in software development. It offers a standardized approach to solve common design problems and helps developers write maintainable, extensible, and reusable code....

Q3: What are the types of design patterns in Java?

Design patterns are like recipes for solving problems in software development. They are helpful because they provide ready-made and flexible solutions to common problems that software developers face. These solutions make the software better. Design patterns are focused on fixing problems in a specific type of software design, like how objects are organized and used. Architectural patterns help us to organize how an application is built. They give us a framework for how everything fits together. They decide what things a big program is made of and how they work together. These patterns help us to make sure that our program is easy to change and can grow to handle lots of users. They also help us to keep our program safe....

Q4: What is the Singleton design pattern in Java?

There are four types of design patterns in Java:...

Q5: What is the Factory Method design pattern in Java?

The singleton design pattern is a way to make sure that only one copy of a class exists. It is used when we want to have a global way to access this class. We use the singleton pattern when we need one object to control things in the whole system....

Q6: What is the Observer design pattern in Java?

...

Q7: What is the Adapter design pattern in Java?

The Factory Method pattern is a way to make things without saying exactly what kind of thing to make. It makes an outline for making things but let’s different kinds of things choose what kind of thing to make. This is helpful when you want to make things without worrying about how they are made....

Q8: What is the Decorator design pattern in Java?

...

Q9: What is the Command design pattern in Java?

The Observer pattern is a way for objects to talk to each other. It’s like when you tell your friends about something, and they all know what’s going on. It’s used when many objects need to know when something happens to one object....

Q10: What is the Iterator design pattern in Java?

...

Q11: What is the Template Method design pattern in Java?

The Adapter pattern helps different things to work together, even if they are not originally made to work together. It changes one thing to be like another thing so that they can work together. This is useful when there are things that cannot work together, but we still need them to work together....

Q12: What is the Builder Method design pattern in Java?

...

Q13: How many ways we you create a singleton pattern?

The Decorator pattern is a way to add new things to an object without changing how it looks or works. You make a new class that goes around the old object and adds new stuff to it....

Q14: Describe the strategy to design a pattern?

...

Q15: What is the decorator pattern in Java explain it with an example?

The Command pattern is a way to organize and control requests in a computer program. Instead of directly giving instructions, we use objects called commands to represent and execute our requests. This helps us use different requests with different clients, keep a record of previous requests, and even undo previous actions. We create an interface or a class to define how commands should be executed, and then create different classes to represent different types of commands....

Q16: Difference between Strategy and State design Pattern in Java?

...

Q17: What are the advantages of Composite Design Pattern in Java?

The Iterator pattern helps us go through a list or a group of things. It keeps the way the group is organized a secret and gives us a way to get to each thing one after the other. It does this by creating a special tool called an Iterator that helps us move through the group....

Q18: Describe the uses of the Composite Design Pattern.

...

Q19: What are Some Design Patterns used in the JDK library?

The Template Method pattern is a way to design things that lets you make a list of steps to do something, but some of the steps can be done in different ways. You start by making a base list of steps, then you make a main step that tells the other steps to run. Each step can be different, and they all work together to do the thing you want to do....

Q20: Advantage of Builder design pattern in Java.

...

Q21: How to write Thread-safe Singleton in Java?

The Builder design pattern is a way to build things step-by-step. It helps you make complicated things using a specific process. This pattern separates the building part from the final thing, so you can make different final things using the same process. The Builder pattern is useful when you want to make complicated things, but the process to make them is simple. It lets you make the thing little by little and then get the final thing when it’s done....

Q22: Is it possible to create a clone of a singleton object?

...

Q23: What is the proxy pattern, and what does it do?

There are two ways of creating a Singleton pattern....

Q24: Explain some different type of proxies?

The following points should need to be taken care to describe the design pattern:...

Q25: Explain the Chain of Responsibility Pattern, when it is used & their advantages.

The decorator pattern is one of the popular Java design patterns. It is common because of its heavy usage in java.io (package). The Decorator Pattern uses composition in place of inheritance to extend the functionality of an object at runtime....

Q26: How Bridge Pattern is different from the Adapter Pattern?

Both Strategy and State patterns have a similar structure. Their UML class diagram looks the same, but they have different purposes. The state design pattern is used to manage and define the state of an object, while the Strategy pattern is used to describe a set of an interchangeable algorithm....

Q27: What is the difference between the Dependency Injection and Service Locator Patterns?

The composite design pattern helps people work together with things that might or might not be part of a group....

Q28: Explain the Intercepting Filter Design Pattern, components and its advantages?

Use cases:...

Q29: Explain Data Access Object (DAO) Design Pattern?

Some of the following design patterns are used in the JDK library:...

Q30: what is the difference between Value Object (VO) and Java Data Object (JDO)?

Immutable Objects: Builders can enforce immutability by setting the object’s fields during construction and providing no way to modify them afterward. Immutable objects are thread-safe by nature, which can help avoid concurrency issues. It facilitates with a clear separation between the construction and representation of an object. It provides improved control over the construction process. Named Parameters: Builders allow you to use named parameters, which enhance code readability by making it clear which value corresponds to which field. In design Pattern, the object is always instantiated in a complete state....

Conclusion

By writing singleton using double-checked locking. By using static Singleton instance initialized during class loading. By using Java enum to create a thread-safe singleton, this is the most straightforward way....