Java Interview Notes: 700 Java Interview Questions Answered

Java Interview Notes incorporate most critical topics discussed during Java technical interview round, along with the interview questions for each concept. This book also contains lots of code snippets and figures to explain matters.



Concepts in the book are organized in very precise and concise manner, in small chapters and are to the point.



CONTENT:



Java Fundamentals:

Java Program Anatomy

Java Program and JVM

Data Types

Naming Convention

Object class

Access Modifiers

static

final

static initialization block

finally()

finalize()

Widening vs Narrowing Conversion

getters and setters

varargs vs object array

default interface method

static interface method

Annotations

Preferences

Pass by value or reference



Object Oriented Programming:

Polymorphism

Parametric Polymorphism

Subtype Polymorphism

Overriding

@Override

Overloading

Abstraction

Inheritance

Composition



Fundamental Design Concepts :

DI vs IoC

Service Locator

Diamond Problem

Programming to Interface

Abstract class vs Interface

Internationalization and Localization

Immutable Objects

Cloning



Data Types :

NaN

EnumSet

Comparing Data Types

Float comparison

String comparison

Enum comparison

enum vs public static int field

Wrapper Classes

Auto boxing and Auto unboxing

BigInteger and BigDecimal



Strings :

String Immutability

String Literal vs Object

String Interning

String Pool Memory Management

Immutability - Security issue

Circumvent String immutability

StringBuffer vs StringBuilder

Unicode



Inner Classes:

Inner Classes

Static Member Nested Class

Local Inner Class

Non-Static Nested Class

Anonymous Inner Class



Functional Programming:

Lambda Expression

Functional Interface

Pure Functions

Fluent Interface



Generics :

Generics

Generics-Type Wildcards

Generics - Method

Java Generics vs Java Array

Generics - Type Erasure

Co-variance

Contra-variance

Co-variance vs Contra-variance



Collections :

Collection design aspects

Collection Fundamentals

Collection Interfaces

Collection Types

Set

List

Queue

Map

Algorithms

Comparable vs Comparator

hashCode() and equals()

HashTable vs HashMap

Synchronized vs Concurrent Collections

Iterating over collections

fail-fast vs fail-safe



Error and Exception:

Exception

Checked vs Unchecked vs Error

Exception Handling Best Practices

try-with-resource



Threading :

Threading Terms

Thread Lifecycle

Thread Termination

Runnable vs Thread

Runnable vs Callable

Daemon Thread

Race Condition and Immutable object

Thread Pool



Synchronization :

Concurrent vs Parallel vs Asynchronous

Thread Synchronization

Synchronized method vs Synchronized block

Conditional Synchronization

Volatile

static vs volatile vs synchronized

ThreadLocal Storage

wait() vs sleep()

Joining Thread

Atomic Classes

Lock

ReadWriteLock

Synchronizers

Barrier

Semaphore

Phaser

Exchanger

Latch

Executor Framework

Executor Service

Fork-Join Framework



Reflection :

Purpose of reflection

Drawbacks of Reflection



Data Interchange:

JSON



Memory Management:

Stack vs Heap

Heap fragmentation

Object Serialization

Garbage Collection

Memory Management

Weak vs Soft vs Phantom Reference



Unit Testing:

Why unit testing?

Unit vs Integration vs Regression vs Validation

Testing private members

Mocking and Mock Objects



Java Tools:

Git

Maven

Ant

Jenkins