Java Masterclass for Absolute Beginners

Learn Java naming conventions: variables and methods use camel case, constants use uppercase with underscores, keywords are lowercase, and packages are lowercase with dots; identifiers cannot start with numbers.

Explore Java data types and variables, distinguishing primitive types (byte, short, int, long, float, double, boolean, char) from non-primitive types (string, array, classes), and learn basic declarations and ranges.

Explore declaring variables and data types in Java, follow naming conventions, create a demo class with a main method, and use the assignment operator to combine values and perform additions.

Explore Java operators, symbols, and keywords that manipulate data by acting on operands. Learn unary and binary operators that work on one or two operands, with operator categories introduced.

Explore the types of operators in Java, from unary operators to arithmetic, assignment, logical, shift, bitwise, ternary, and relational operators, with upcoming detailed coverage.

Explore arithmetic operators such as addition, subtraction, multiplication, division, and modulo, with operands, increment, and decrement. Explain the assignment operator and compound forms like x += 5.

Explore how comparison operators evaluate equal to, not equal to, greater than, and less than for if-else logic, and how logical operators and, or, not combine booleans.

Explore bitwise and, logical operators in Java, convert numbers to bits, apply and, or, xor, not, and shifts, and use the ternary operator as a shorthand for if-else.

Explore bitwise and ternary operators while learning Java data types and variables, declare float, double, boolean, short, long, String, and char, and perform and print operations.

Learn how to use for loops to perform repetitive tasks in Java, including initialization, condition checking, and increment, with examples that print ranges, handle odd numbers, and compute sums.

Demonstrate when to use for versus while loops in Java, and master the three loop parts—initialization, condition, and increment—by printing numbers and applying odd or even logic.

Explore the do while loop and compare it with for and while loops, showing how a loop can execute at least once and detailing initialization, body, condition, and increment.

Learn Java control statements with if conditions to decide outcomes like voting eligibility by age, and combine with for, while, and do-while loops, plus else and else if.

Learn to build a Java grade calculator using an if-else ladder, handling double marks, total marks, and max value, and output results with System.out.println.

Turn a static Java program into a dynamic one by using a Scanner to read user input, prompting for marks, and handling data with next double and next line.

Build a never-stopping Java program using a do loop with while true to read marks and assign grades with if, else if, else, and observe print versus println output.

Explore the ternary operator in Java as a concise shorthand for if-else, using a true/false condition to return values and print the result.

Explore switch case statements to control program flow, including default blocks and break to prevent continuing to other cases, and observe break behavior in loops.

Define classes as blueprints and objects as real-world instances in object oriented programming, then explore how states and behaviors drive unique object details like name and roll number through methods.

Identify six core concepts of object oriented programming—class, objects, inheritance, polymorphism, abstraction, and encapsulation—and how they define object oriented programming.

Understand object oriented programming through abstraction, polymorphism, inheritance, and encapsulation, using abstract classes and interfaces. See how overloading and overriding drive static and dynamic binding for reusable, secure Java code.

Explore how Java memory splits into heap for objects and stack for references, with S1 moving from null to referencing the new object in the heap.

Explore Java objects and classes by building an Employee with state and behavior, using getters and setters, understanding object references, memory layout, and overriding toString for readable output.

learn how constructors work in Java, a special method with the class name, default and parameterized constructors, overloading and static polymorphism, illustrated with a sample area class.

Explore how arrays in Java store multiple items of the same type, including dynamic allocation, array length, one- and multi-dimensional arrays, and passing or returning arrays in methods.

Explore core Java array concepts with hands-on examples in int arrays, default values, for loops, array length, element search, and basic manipulation.

Explore a practical mini project that builds and manipulates an array of employee IDs in Java, including dynamic sizing, user input, and basic options for sorting and searching.

Master the static keyword in Java, covering blocks, variables, and methods. Learn class loading time, static access via class name, and this or super is not allowed in static context.

Learn how final applies to variables, methods, and classes in Java, including initialization rules and non-reassignment of references. Final methods cannot be overridden and final classes cannot be inherited.

Discover how Java strings work, including string literals, new objects, string pool, immutability, and memory-friendly string builder, plus substring, indexOf, trim, replace, split, and valueOf.

Master hands-on Java string operations, compare references versus values for literals and new objects, and apply methods like substring, indexOf, startsWith, endsWith, contains, trim, and intern.

Explore how the string compareTo method works in Java by building a class and main method, testing s1 and s2 literals, and observing zero, positive, and negative results.

Explore how Java access modifiers control visibility of classes, methods, and fields using public, private, protected, and default. Learn how package scope and inheritance affect access across packages.

Explore how Java access modifiers control visibility by building animal, bird, and cat classes across packages, using private, default, protected, and public members, plus getters and inheritance.

Explore how Java collections extend arrays by storing multiple elements with set, list, map, and queue, and compare synchronization, ordering, null handling, and common implementations.

Learn how Java generics enforce type safety with ArrayList by restricting elements to a data type, and see how mismatched types trigger compile errors.

Create an employee class with private fields and a constructor, generate getters and setters, and demonstrate dynamic polymorphism with lists, maps, and iterations, printing employee ids and names.

Build and manipulate a fruit list using ArrayList, performing add, get, set, remove, size, contains, and isEmpty operations, including null values. Demonstrate dynamic polymorphism with List, ArrayList, and LinkedList.

Practice hands-on in Java by building and iterating generics-based maps and array lists, storing employees with integer keys, handling nulls, and exploring nested maps and lists.

Master exception handling in Java by distinguishing checked and unchecked exceptions, understanding errors vs exceptions, and creating and throwing custom exceptions with try, catch, and finally.

Explore practical exception handling in Java, including division by zero and runtime versus arithmetic exceptions. See how try-catch blocks, debugging with breakpoints, and evaluation reveal exception flows and graceful termination.

Explore how to create and throw a custom exception in Java, integrate error codes and messages with encapsulation, and understand checked exceptions, propagation, and handling in business logic.

Explore the concept of multithreading in Java, distinguishing threads from processes and showing how multiple threads run in parallel and share memory with their own stacks.

Learn to create threads in Java by implementing Runnable or extending Thread, understand the start and run methods, and explore thread lifecycles and basic synchronization.

Explore thread synchronization in Java by managing shared resources with synchronized methods and blocks, preventing data races during multi-threaded access such as bank balance updates.

Explore threads in Java by creating and running threads, and implementing runnable versus extending thread. Learn to set thread priorities and names, use sleep, and observe the scheduler's nondeterministic execution.

Explore Java file handling with the java.io package, using the file class to read, write, create, and delete files, and understand byte and character streams for input and output.

In this Java masterclass, build a bookstore app with author, customer, and book objects, implementing create, view, update, delete, search, and order workflows, with extendable reports.

Create a java project in eclipse or sts named bookstore_app with jdk 11 and a src folder, then set up the workspace and create packages and classes for bookstore app.

Explore how a sequence diagram maps interactions between Java classes—order controller, order service, and repository—checking inventory via a book service, and converting between DTO and entity across layers.

Explore sequence diagrams mapping interactions for viewing books, reviewing details, searching, and placing orders, and examine class diagrams with book, author, and order entities, pojos, interfaces, controllers, services, and repositories.

Learn how to structure a Java project with unified modeling language diagrams and a layered architecture, creating packages for entity, repository, service, controller, dto, and converter.

Create a book entity and its dto by defining private fields, generating getters and setters, and applying Pascal naming for classes with camel casing for fields.

Save a book entity in a repository using a list and return its ID; explain in-memory data loss on stop and introduce serialization to a file with deserialization to restore.

Serialize a book entity to a file by using the serializable interface with java.io, file output stream, and object output stream to achieve persistence after application stops.