1.1 - Introduction to PRG37(8)1.pdf

PRG37(8)1 Programming in Java  PRG 37(8)1 IMPORTANT INFORMATION DURATION ASSESSMENTS 2 1 Project [M1 & M2] Assessment 30...

PRG37(8)1 Programming in Java  PRG 37(8)1 IMPORTANT INFORMATION DURATION ASSESSMENTS 2 1 Project [M1 & M2] Assessment 30 Weights CT weeks 1 Tests 35 x2 Project [M1,M2] 100 Total  Outcomes  An understanding of integrated knowledge of programming techniques and concepts as contested to construct computing systems using tools and services to develop computing systems that consider platform constraints, supports version control, tracks requirements and bugs, and automates building.  The ability to identify, analyse, evaluate, critically reflect on and address complex problems, applying evidence-based solutions and theory-driven arguments through the use of application programming interfaces and frameworks when implementing solutions.  An understanding of a range of methods to construct multi-tiered applications, evaluate and verbalize the value of using the different levels of logic separation.  The ability to develop and communicate a solid understanding of the more advanced concepts of programming inclusive of data structures, design patterns and RESTful API implementation.  The ability to take full responsibility for their own work, decision-making and use of resources to solve problems in unfamiliar and variable contexts exposed by different technologies and methodologies for tasks and be able to judge the relative merits of these to choose between the alternatives.  Java Programming  Java is a popular programming language, created in 1995.  It is owned by Oracle, and more than 3 billion devices run Java.  It is used for:  Mobile applications (specially Android apps)  Desktop applications  Web applications  Web servers and application servers  Games  Database connection  Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX.  Concepts of Java  Key Core Java concepts: 1) Java Fundamentals - the main variant of Core Java, typically used for developing regular desktop applications. 2) Collections: involves managing mainly data structures, like lists, maps, sets, etc., which provide different algorithms to handle storage. 3) OOPs Concepts: Classes, Objects, Encapsulation, Polymorphism, Inheritance. 4) Packages: form the Core Java concepts that allow the organisation and grouping of related classes and interfaces.  Concepts of Java  Key GUI and Server-side Java concepts: 5) Java Swing: a Graphical User Interface in the concept of Core Java that helps to develop desktop apps with a quality graphical interface. 6) Java Database Connectivity (JDBC): a fundamental technology that allows Java applications to interact with databases for CRUD operations. 7) PostgreSQL (Postgres): a powerful open-source relational database management system (RDBMS) known for its reliability, scalability, and extensibility. 8) Java Servlets: server-side programs written in Java that handle requests and generate responses in a web environment.  Installing Java  Search: Choose Java SE 21 Archive  Installing Java  Choose installer compactible with your device:  Install:  Installing Java IDE  Search for IntelliJ IDEA:  Installing Java IDE  Download Community Edition:  Install:  Installing Java IDE  Setup of Environment Variables:  Installing Java IDE  Reboot your PC:  Installing Java IDE  Name your project > choose Location folder:  Installing Java IDE  First HelloWorld project: Output:  To Run, click: Or:  Java Cheat Sheet  Download the Java Cheat Sheet: https://codewithmosh.lpages.co/java-cheat-sheet/  Executing Java  Running a Java application involves two main stages: compilation and execution.  Executing Java Compilation 1) Source Code (.java):  The Java application starts as human-readable source code files with a ".java" extension.  This source code contains the instructions and logic written by the developer. 2) Compiler (javac):  The source code is then compiled using the Java compiler (javac).  The compiler translates the Java source code into bytecode.  Bytecode is a set of instructions understood by the Java Virtual Machine (JVM). 3) Bytecode (.class):  The output of the compilation process is one or more bytecode files with a ".class" extension.  These bytecode files contain instructions in a platform-independent format.  Executing Java Execution: 1) Java Virtual Machine (JVM):  The JVM executes Java bytecode.  The JVM is platform-dependent, meaning there are different implementations for Windows, Mac, Linux, etc. but they all adhere to the Java Virtual Machine Specification. 2) Interpreter and Just-In-Time (JIT) Compiler:  JVM loads the bytecode and the JVM's interpreter reads and executes the bytecode.  Uses Just-In-Time (JIT) compile which dynamically compiles bytecode into native machine code for the specific hardware it's running on, which is much faster than interpreting bytecode directly. 3) Native Code Execution:  The JIT compiler generates native machine code specific to the hardware and operating system.  This native code is executed directly by the processor, whether it’s on a Windows, Mac, Linux, or any other supported environment.  The Java Environment  Java runs on a hypothetical computer known as the Java Virtual Machine (JVM).  Java Program Types You can write different kinds of programs using Java: 1) Desktop Applications - Graphical User Interface (GUI) Applications using libraries like Swing and JavaFX. 2) Web Applications - Dynamic Web Applications like Servlets, JSP, and frameworks like Spring and JSF. 3) Mobile Applications - Apps for Android devices, developed using the Android SDK. 4) Enterprise Applications - Large-scale, complex systems for businesses, including CRM systems, ERP systems, and inventory management, using Java EE (Jakarta EE) technologies. 5) Server-Side Applications - Backend applications running on servers, including RESTful APIs, microservices, and high-performance server-side applications.  Java Console Applications  Anatomy of Java program:  Java Console Applications  Anatomy of Java statement:  Java Variables  Temporary storage space for a value (number, word etc.)  Variable Declaration:  Variable Initialization:  Java Types  Two examples exists:  Java Primitive Types  Declaring different types:  Formatting Strings  The String.format() method in Java allows you to create formatted strings by replacing placeholders with values. It provides a flexible way to control the appearance of the output.  format: A format string containing placeholders for values. Placeholders are marked by % followed by a format specifier (e.g., %s, %d, %f).  args: Optional arguments to replace the placeholders in the format string.  Java Reference Types  Reference types are data types that store references (memory addresses) to objects rather than the actual object data itself. ‘new String()’ is redundant  Java Reference Types  ‘new String()’ is redundant - using new String() to create a new String object is considered redundant in most cases.  This is because Java provides a convenient string literal syntax, where you can directly assign a string value enclosed in double quotes to a String variable without using the new keyword:  Both str1 and str2 will contain the string "Hello", but the first approach is simpler and more efficient.  It is recommended to use string literals instead of new String() to create String objects in Java.  Since strings are object reference type in Java, they come with a variety of methods for manipulating and working with strings. String Methods in Java String Methods in Java  Input and Output in Java  In Java, you can perform input and output operations using the console using:  the System.in stream  the System.out stream  Console Output Formatting:  You can use formatting options with System.out.printf() for more control over output formatting.  Exercises 1. What is the character at index 3 in the string : String str = "Hello World"; 2. What is the length of the string: String str = "Java Programming"; 3. What is the substring of "Hello World" starting from index 6? 4. What is the substring of "Hello World" from index 3 to index 7? 5. What is the index of the first occurrence of "world" in the string: String str = "Hello world, welcome to the world";  Exercises 6. What is the index of the last occurrence of "the" in the string: String str = "The quick brown fox jumps over the lazy dog"; 7. Does the string "Java Programming" start with "Java"? 8. Remove leading and trailing whitespace from the string " Java Programming “ 9. Replace all occurrences of 'o' with 'x' in the string "Hello World". 10. Split the string "Java Programming is fun" into an array of words.  Exercises 11. What are Features of Java Programming? 12. Differentiate between Java Applets and Applications? 13. Explain the Importance of JVM. 14. What is the role of Java in Internet? 15. Create a console Java App that outputs the following:  3 6 Thank You! The End /belgiumcampusSA #Belgium Campus [email protected] +27 10 593 53 68 /belgiumcampus 36 www.belgiumcampus.ac.za