Lesson 1

The primary objective of this module is to get you ready to start writing programs using the Java programming language. As you learn the basic principles of programming there is no better way to reinforce these ideas than to put them into practice.
After completing this module you will have the skills and knowledge necessary to:

1. Download and install the Java 2 Software Development Kit
2. Compile a Java program
3. Run a Java program
4. Use comments and indentation in a Java program

The software engineer’s job is to solve problems economically by developing high-quality software. In this first chapter we will present important issues that all software engineers should understand to do their jobs well.

To effectively program in Java, it's essential to understand various software engineering concepts that form the foundation of writing robust, efficient, and maintainable code. Below are the key concepts you should be familiar with:

1. Basic Programming Constructs:
   • Variables and Data Types: Understanding primitive types (int, char, double, etc.) and reference types (Objects, Arrays).
   • Operators: Arithmetic, relational, logical, and bitwise operators.
   • Control Flow Statements: `if`, `else`, `switch`, loops (`for`, `while`, `do-while`).
2. Object-Oriented Programming (OOP) Concepts:
   • Classes and Objects: Defining classes and creating objects as instances of classes.
   • Encapsulation: Hiding the internal state of an object and requiring all interaction to be performed through an object's methods.
   • Inheritance: Creating new classes that are based on existing classes.
   • Polymorphism: Allowing entities to take on multiple forms, enabling a single interface to represent different underlying forms (data types).
   • Abstraction: Simplifying complex reality by modeling classes appropriate to the problem.
3. Data Structures and Algorithms:
   • Collections Framework: Understanding `List`, `Set`, `Map`, and their implementations like `ArrayList`, `HashSet`, `HashMap`.
   • Algorithms: Basic sorting (bubble sort, quicksort) and searching algorithms.
4. Exception Handling:
   • Try-Catch Blocks: Handling exceptions to prevent program crashes.
   • Custom Exceptions: Creating your own exception classes.
5. Concurrency and Multithreading:
   • Threads: Creating and managing threads using `Thread` class and `Runnable` interface.
   • Synchronization: Handling shared resources to prevent race conditions.
   • Concurrency Utilities: Using higher-level concurrency APIs like `ExecutorService`, `ConcurrentHashMap`.
6. Design Patterns:
   • Creational Patterns: Singleton, Factory, Builder.
   • Structural Patterns: Adapter, Decorator.
   • Behavioral Patterns: Observer, Strategy
7. Software Development Lifecycle (SDLC):
   • Requirement Analysis: Understanding what needs to be developed.
   • Design: Planning the solution architecture.
   • Implementation: Writing the code.
   • Testing: Verifying that the code works as intended.
   • Maintenance: Updating and fixing issues after deployment.
8. Version Control Systems:
   • Git: Tracking changes in source code during software development.
   • Branching and Merging: Working with multiple development lines.
9. Testing and Debugging:
   • Unit Testing: Writing tests for individual units of code using frameworks like JUnit.
   • Debugging Tools: Using IDE debuggers to step through code and inspect variables.
10. Software Design Principles:
    • SOLID Principles: Guidelines for writing clean and maintainable code.
      • Single Responsibility Principle:
      • Open/Closed Principle:
      • Liskov Substitution Principle:
      • Interface Segregation Principle
      • Dependency Inversion Principle:
    • DRY (Don't Repeat Yourself)
    • KISS (Keep It Simple, Stupid)
11. Build Tools and Dependency Management: Maven and Gradle: Automating the build process and managing project dependencies.
12. Understanding the Java Ecosystem:
    • Java Virtual Machine (JVM): How Java code is executed.
    • Standard Libraries: Utilizing built-in libraries for I/O, networking, utilities, etc.
    • Java Development Kit (JDK): Tools required for developing Java applications.
13. Memory Management:
    • Garbage Collection: Understanding how Java handles memory allocation and deallocation.
    • Memory Leaks: Identifying and preventing situations where memory isn't properly released.
14. Security Practices:
    • Secure Coding: Writing code that is resistant to attacks.
    • Authentication and Authorization: Managing user access and permissions.
15. Web Development Concepts (if applicable):
    • Servlets and JSP: Building server-side applications.
    • Frameworks: Understanding popular frameworks like Spring and Hibernate.
16. APIs and External Libraries:
    • RESTful Services: Consuming and creating REST APIs.
    • JSON and XML Parsing: Handling data interchange formats.
17. Deployment and Continuous Integration:
    • CI/CD Pipelines: Automating the build, test, and deployment processes.
    • Containers: Using Docker for containerization.

By mastering these software engineering concepts, you'll be well-equipped to develop robust Java applications that are efficient, scalable, and maintainable. It's also beneficial to engage with the Java community, contribute to open-source projects, and stay updated with the latest developments in the Java ecosystem.

Similarly to mechanical engineers who design mechanical systems and electrical engineers who design electrical systems, software engineers design software systems. However, software differs in important ways from the types of artifacts produced by other types of engineers: Software is largely intangible. Unlike most other engineering artifacts, you cannot feel the shape of a piece of software, and its design can be hard to visualize. It is therefore difficult for people to assess its quality or to appreciate the amount of work involved in its development. This is one of the reasons why people consistently underestimate the amount of time it takes to develop a software system. In the next module you will learn how Java will be used in the course.