Core Java Notes 

 

Unit-wise Java syllabus breakdown

Unit 1: Java Basics

- What is Java? (History, language, platform)

- Applications of Java (Desktop, Web, Enterprise, Mobile, Embedded, Smart Card, Robotics, Games)

- Features of Java (Simple, Object-oriented, Platform Independent, Secured, Robust, Architecture-neutral, Portable, High-performance, Distributed, Multi-threaded, Dynamic)

- First Java Program (Structure, use of class, public, static, void, main, System.out.println, runtime steps)

- Saving/Compiling Java source files (file vs. class names, multiple classes)

- JDK, JRE, JVM differences

- Variables (Local, Instance, Static)

- Data types (Primitive & Non-primitive)

- Unicode system (motivation, 2-byte character, ranges)

- Operators (Unary, Arithmetic, Shift, Relational, Bitwise, Logical, Ternary, Assignment)

- Keywords (reserved words)  

Unit 2: Control Flow & Object-Oriented Programming

- Control Statements:

  - Decision making: if, if-else, if-else-if ladder, nested if

  - switch statement

  - Loops: for, for-each, while, do-while

  - Jump statements: break, continue

- OOPs Concepts:

  - Object, Class

  - Inheritance (single, multilevel, hierarchical), Aggregation, Association, Composition

  - Polymorphism (Method Overloading, Method Overriding, Compile/Runtime)

  - Abstraction, Encapsulation, Coupling, Cohesion

- Constructors: usage, overloading, singleton, private constructor, rules

- Important Keywords: this, static, super, final, instance initializer block

- Upcasting, static vs. dynamic binding, covariant return types, instanceof  

Unit 3: Abstraction, Interfaces, Packages & Arrays

- Abstract class, abstract methods

- Interfaces (syntax, marker/tagged, Java 8+ features)

- Difference: abstract class vs interface

- Packages & sub-packages (built-in, user-defined)

- Access Modifiers (private, default, protected, public, comparison table)

- Encapsulation (getters/setters, data hiding, logic control)

- Arrays (single and multi-dimensional, advantages, limitations)  

Unit 4: Strings, Wrappers & Miscellaneous

- String Handling (creation, immutability, StringBuffer/StringBuilder, differences)

- Methods: toString(), StringTokenizer

- Wrapper Classes (autoboxing, unboxing, primitive ↔ object conversion)

- strictfp keyword

- Object class basics, object cloning

- Math class (mathematical functions)

- Comparisons: Object vs Class, Overloading vs Overriding  

Unit 5: Exception Handling & Multithreading

- Exception Handling

  - Types (Checked, Unchecked, Error)

  - try-catch, multi-catch, nested try

  - finally, throw, throws, exception propagation

  - Custom exceptions

  - final vs finally vs finalize, throw vs throws

- Multithreading

  - Concept, multitasking types

  - Thread class vs Runnable interface, Thread life cycle, thread methods, state

  - Thread Scheduler (algorithms: FCFS, Time-Slicing, Preemptive), Thread.sleep(), join(), set/getName(), priority

  - Daemon threads, Thread pool, ThreadGroup, Shutdown hook

  - Single task vs multiple tasks

  - Garbage collection: ways to unreference, finalize(), gc(), Runtime class  

Unit 6: Java Collections Framework

- Overview & architecture

- List:

  - ArrayList, LinkedList, Vector, Stack, comparisons

- Set:

  - HashSet, LinkedHashSet, TreeSet, EnumSet

- Queue & Deque:

  - PriorityQueue, Deque, features (FIFO/LIFO)

- Map:

  - HashMap, LinkedHashMap, TreeMap, Hashtable, Map hierarchy, comparisons (HashMap vs Hashtable)

- Collections class

- Comparable vs Comparator  

Unit 7: JDBC & Reflection

- JDBC:

  - Overview, API, main interfaces/classes (Driver, Connection, Statement, PreparedStatement, CallableStatement, ResultSet, ResultSetMetaData, DatabaseMetaData, RowSet, DriverManager)

  - Types of JDBC drivers (JDBC-ODBC bridge, Native-API, Network Protocol, Thin driver)

  - Steps for database connection (register driver, get connection, create statement, execute query, close connection)

  - Why JDBC vs ODBC

- Java Reflection API:

  - Purpose, meta-programming

  - java.lang.Class, reflection packages