Thu Jan 03 20:01:06 PST 2019

Java Programming Language

Java Recent Articles!

Java Output & Multiple Choice Questions

Overview, Basics, � OOP concepts, Inheritance � Operators, � Strings, � Input and Output, Arrays , Arrays Class, �Important Keywords in Java ,Java vs C++, � Methods in Java, � Constructors, � Exception Handling, Regular Expressions, Interfaces and Abstract Classes, Java Packages, Multithreading, � Garbage Collection,�Wrapper Classes, Reflection in Java, � File Handling, � Collection in Java, Collection Interview FAQ?s� ,Collections Class (Contains utility functions on Collections), � Useful and/or Advanced Features, � Image Processing, �Networking in Java, Interview Questions, Misc, Multiple Choice Questions, Java 8 Stream Methods

Overview

• How to start learning Java
  
• Setting up the environment


• The Hello World Example(Practice)


• Java Naming Conventions


• JVM


• JVM Stack Area
  
• JVM Shutdown Hook


• Java Class File
  
• Differences between JDK, JRE and JVM


• Does JVM create object of Main class?


• How is Java platform independent?


• JDBC Drivers


• Is main method compulsory in Java?


• File names and class names


• How to run java class file which is in different directory?


• Microservices Introduction
  
• Using predefined class name as Class or Variable name in Java


• How do I become a good Java programmer?
  

Basics

• Java Identifiers


• Data types


• How to define our own data type in java(enum)


• Enum with Customized Value


• StringBuffer appendCodePoint() Method


• Variables


• Scope of Variables


• Final variables


• Bounded Type Parameters


• Loops in Java(Practice)


• For-each loop in Java


• For Loop in Java | Important points


• Decision Making(if, if-else, switch, break, continue, jump)(Practice)


• Switch Statement in Java(Practice)


• String in Switch Case in Java


• Forward declarations


• Widening Primitive Conversion�


• Type conversion in Java


• Comments in Java


• Does Java support goto?


• Interesting facts about null in Java


• Using _ (underscore) as variable name


• Currying Functions in Java with Examples
  
• Using underscore in Numeric Literals


• Binary search in Java


• Sorting in Java

OOP concepts

• Classes and Objects


• Java object storage


• Different ways to create objects in Java


• How to swap or exchange objects


• Inheritance in Java


• Encapsulation in Java


• Abstraction in Java


• Run-time Polymorphism in Java


• Association,Composition and Aggregation


• Access and Non Access Modifiers in Java


• Access Modifiers


• this reference


• Method Overloading


• Output of Java program | Set 22 (Overloading)


• Method Overriding


• Output of Java program | Set 18 (Overriding)


• Understanding ?static? in ?public static void main? in Java
  
• Overloading or Overriding static methods


• Shadowing of static methods(Also called Method Hiding)


• Static methods vs Instance methods in Java


• Assigning values to static final variables in Java


• Covariant return types


• Object class


• Static class in Java


• Flexible nature of java.lang.Object


• Overriding equals method of Object class


• Overriding toString() method of Object class


• Instance Variable Hiding�


• Static blocks in Java


• initializer block in java


• instance initializer block in java(non-static block)


• Static vs Dynamic Binding


• Why Java is not a purely Object-Oriented Language?


• Understanding Classes and Objects in Java
  

Inheritance

• Inheritance in Java


• Multiple Inheritance


• Why Java does?nt support Multiple Inheritance ? The Diamond Problem


• Java Object Creation of Inherited Class


• Inheritance and constructors


• Interfaces and Inheritance


• Using final with Inheritance


• Accessing Grandparent?s member


• Override private methods


• More restrictive access to a derived class method in Java


• Parent and Child classes having same data member�


• Object Serialization with Inheritance


• Referencing Subclass objects with Subclass vs Superclass reference


• Does overloading work with inheritance


• Output of Java Program | Set 20 (Inheritance)

Operators

• All Operators
  
• Bitwise operators in Java
  
• new operator


• Bitwise right shift operators


• Java instanceof operator and its applications


• Autoboxed Integer objects


• Addition and Concatenation


• Numeric Promotion in Conditional Expression

Input and Output

• Character Stream Vs Byte Stream


• DoubleStream mapToObj() in Java
  
• Command Line arguments


• Scanner Class


• Scanner and nextChar()


• Scanner vs BufferReader Class


• Formatted output


• Fast I/O for�Competitive Programming


• Reading input from console

Strings in Java

• String Class(Practice)


• StringBuffer Class


• StringBuilder Class


• StringTokenizer class ? Set 1, Set 2


• StringJoiner in Java8


• Implementations:
  
  
  
  • Initialize and Compare Strings�
  
  
  • String vs StringBuilder vs StringBuffer
  
  
  • When to use StringJoiner over StringBuilder?
  
  
  • Integer to String Conversions
  
  
  • String to Integer? parseInt()
  
  
  • Swap two Strings without using third variable�
  
  
  • Searching characters and substring in a String
  
  
  • Compare two Strings in Java
    
  • Reverse a string in Java (5 Different Ways)
  
  
  • Remove Leading Zeros From String in Java
  
  
  • Trim (Remove leading and trailing spaces) a string
  
  
  • Counting number of lines, words, characters and paragraphs in a text file using Java
  
  
  • Check if a string contains only alphabets in Java using Lambda expression
    
  • Remove elements from a List that satisfy given predicate in Java
    
  • Check if a string contains only alphabets in Java using ASCII values
    
  • Check if a string contains only alphabets in Java using Regex
    
  • More >>
  
  
  
  

Arrays in Java

• Arrays in Java(Practice)


• Default Array values


• Util Arrays Class (Contains utility functions for Arrays)


• Reflect Array class in Java


• util.Arrays vs reflect.Array in Java


• Final arrays


• Interesting facts about Array assignment in Java


• Jagged Array


• Array IndexOutofbounds Exception


• Array vs ArrayList in Java


• Implementations:
  
  
  
  • Compare two arrays�
  
  
  • ArrayList to Array Conversion�
  
  
  • Merge arrays into a new object array in Java
  
  
  • More >>
  
  
  
  

Stream in Java

• Java Stream


• Java Stream.Builder


• Java IntStream


• Java IntStream.Builder


• Java LongStream


• Java LongStream.Builder


• Java DoubleStream


• Java DoubleStream.Builder


• Java Stream Collectors


• Implementations:
  
  
  
  • 10 Ways to Create a Stream in Java
  
  
  • How to print elements of a Stream in Java 8
  
  
  • Program to Iterate over a Stream with Indices in Java 8
  
  
  • How to get ArrayList from Stream in Java 8
  
  
  • More >>
  
  
  
  

Important Keywords

• List of all Java Keywords
  
• Important Keywords in Java


• this keyword


• super Keyword


• static keyword


• final keyword


• final, finally and finalize in Java


• abstract Keyword


• transient keyword in Java


• volatile keyword in Java


• strictfp keyword

C++ vs Java

• C++ vs Java


• Static keyword in C++ vs�Java


• Exception Handling in C++ vs�Java


• Inheritance in C++ vs�Java


• Virtual behavior differ in C++ vs�Java


• Foreach in C++ and Java


• C/C++ Pointers vs Java References


• Comparison of boolean data type in C++ and Java


• Floating Point Operations & Associativity in C, C++ and Java

Methods in Java

• Methods


• Parameters passing


• Returning Multiple values


• Throwable fillInStackTrace() method in Java
  
• Valid variants of main()


• Variable Arguments (Varargs) method


• Method Overloading


• Different ways of Method Overloading in Java


• Method overloading and null error


• Method Overloading with Autoboxing and Widening


• Method Overloading and Ambiguity in Varargs


• Overloading main()


• Overriding equals method


• Overriding toString() method


• Private and final methods


• Java is Strictly Pass by Value


• Clone() method


• Remote Method Invocation


• Default Methods


• Passing and Returning Objects in Java


• Date after() method in Java
  
• System.exit() method

Constructors

• Constructors in Java


• Default constructor


• Assigning values to static final variables


• Copy Constructor


• Constructor Chaining


• Private Constructors and Singleton Classes


• Java Interview Questions on Constructors


• Singleton Class


• Constructor Overloading


• Output of Java Programs | Set 14 (Constructors)

Exception Handling

• Exceptions


• OutOfMemoryError Exception


• 3 Different ways to print Exception messages in Java


• flow control in try-catch-finally


• Types of Exceptions


• Catching base and derived classes as exceptions


• Checked vs Unchecked Exceptions


• Throw and Throws


• User-defined Custom Exception


• Infinity or Exception?


• Multicatch


• Chained Exceptions


• Null Pointer Exception


• Output of Java program | Set 12(Exception Handling)

Interfaces and Abstract Classes

• Interfaces


• Access specifier for methods in interfaces


• Access specifiers for classes or interfaces


• Abstract Classes


• Difference between Abstract Class and Interface in Java


• Comparator Interface


• Java Interface methods


• Nested Interface


• Nested Classes in Java


• Inner class in java


• Local Inner Class in Java


• Anonymous Inner Class in Java


• Functional Interfaces


• What is a Marker interface


• Questions on Abstract Classes and Interfaces


• Output of Java program | Set 15 (Inner Classes)


• Static method in Interface in Java
  
• Function Interface in Java with Examples
  

Apache in Java

• Apache POI | Introduction
  
• Apache POI | Getting Started
  
• Reading and Writing data to excel file using Apache POI
  
• Creating Sheets in Excel File in Java using Apache POI
  
• Creating a Cell at specific position in Excel file using Java
  
• Opening Existing Excel sheet in Java using Apache POI
  

Java Packages

• Packages Introduction


• java.io package


• java.lang package


• java.util package

Collection in Java

• Collection:
  
  
  
  • AbstractCollection
  
  
  • Collections Class in Java
  
  
  • Enumeration, Iterators and ListIterators
    
    
    
    • Convert an Iterable to Collection in Java
    
    
    • Using Iterators
    
    
    • Iterator vs Foreach
    
    
    • Types of iterator
    
    
    • Creating Sequential Stream from an Iterator in Java
    
    
    
    
  
  
  • Implementations:
    
    
    
    • Output of Java Program | Set 13(Collections)
    
    
    • Double Brace Initialization
    
    
    
    
  
  
  
  


• List:
  
  
  
  • AbstractList
  
  
  • AbstractSequentialList
  
  
  • ArrayList (Practice)
  
  
  • LinkedList
  
  
  • Immutable List in Java (Guava)
  
  
  • java.util.Concurrent:
    
    
    
    • CopyOnWriteArrayList
    
    
    
    
  
  
  • Implementations:
    
    
    
    • Custom ArrayList in Java
    
    
    • Java Collection| Difference between Synchronized ArrayList and CopyOnWriteArrayList
    
    
    • More >>
    
    
    
    
  
  
  
  


• Queue:
  
  
  
  • AbstractQueue
  
  
  • java.util.Concurrent:
    
    
    
    • ArrayBlockingQueue
    
    
    • ConcurrentLinkedQueue
    
    
    • LinkedBlockingQueue
    
    
    • LinkedTransferQueue
    
    
    • PriorityBlockingQueue
    
    
    
    
  
  
  
  


• Deque:
  
  
  
  • ArrayDeque
  
  
  • java.util.Concurrent:
    
    
    
    • ConcurrentLinkedDeque
    
    
    • LinkedBlockingDeque
    
    
    
    
  
  
  
  


• Set:
  
  
  
  • AbstractSet
  
  
  • EnumSet
  
  
  • HashSet
  
  
  • TreeSet
  
  
  • java.util.Concurrent:
    
    
    
    • ConcurrentSkipListSet
    
    
    • CopyOnWriteArraySet
    
    
    • LinkedHashSet
    
    
    
    
  
  
  • Implementations:
    
    
    
    • Internal working of Set/HashSet
    
    
    • Merge two sets in Java
    
    
    • Disjoint Set Data Structures (Java Implementation)
    
    
    • More >>
    
    
    
    
  
  
  
  


• Map:
  
  
  
  • EnumMap
  
  
  • HashMap
  
  
  • SortedMap
  
  
  • WeakHashMap
  
  
  • ImmutableMap (Guava)
  
  
  • LinkedHashMap
  
  
  • IdentityHashMap
  
  
  • Dictionary
  
  
  • java.util.Concurrent:
    
    
    
    • ConcurrentHashMap
    
    
    
    
  
  
  • Implementations:
    
    
    
    • Working of HashMap
    
    
    • Traverse through a HashMap in Java
    
    
    • Program to Convert HashMap to TreeMap in Java
    
    
    • More >>
    
    
    
    
  
  
  
  


• HashTable


• Stack


• Vector

Collection Interview FAQ?s

• Vector vs ArrayList


• ArrayList vs LinkedList


• Comparable vs Comparator


• Differences between TreeMap, HashMap and LinkedHashMap


• HashMap vs�HashTable


• Hashmap vs WeakHashMap in Java


• How to Synchronize ArrayList in Java


• ArrayList and LinkedList remove() methods


• How to Remove an element from ArrayList

Java.nio

• IntBuffer methods in Java
  
• FloatBuffer methods in Java
  
• DoubleBuffer methods in Java
  
• ShortBuffer methods in Java
  
• ByteBuffer methods in Java
  
• CharBuffer methods in Java
  

Java.Security

• Signature methods in Java
  
• SecureRandom methods in Java
  
• KeyPairGenerator methods in Java
  
• KeyFactory methods in Java
  
• AlgorithmParameterGenerator methods in Java
  
• Provider methods in Java
  

Multithreading

• Multithreading


• Lifecycle and states of a thread


• Main thread


• Methods to prevent thread execution


• inter thread communication


• Java.lang.Thread class


• Start() function in multithreading�


• Java Thread Priority


• Joining Threads in Java


• Naming a thread and fetching name of current thread in Java


• Synchronization


• Method and Block Synchronization


• Producer-Consumer solution


• Thread Pools in Java


• Semaphore in Java


• Java.util.concurrent.Semaphore class in Java


• CountDownLatch


• Deadlock in java


• Daemon thread


• Reentrant Lock


• Cyclic Barrier in Java


• Callable and Future in Java


• Runtime Class


• Output of Java program | Set 16 (Threads)

Garbage Collection

• Garbage Collection


• How to make object eligible for garbage collection in Java?


• Mark-and-Sweep


• Island of Isolation


• Automatic Resource Management


• Output of Java programs | Set 10 (Garbage Collection)


• Iterator vs Collection in Java
  

Wrapper Classes

• Wrapper Classes in Java


• Primitive Wrapper Classes are Immutable in Java


• Number Class


• Integer class


• Byte class


• Short class


• Long class


• Float class


• Double class


• Boolean Class


• Character Class


• Autoboxing and Unboxing in Java

Reflection in Java

• Reflection in Java


• Method Class in Java


• Reflect Array class in Java


• util.Arrays vs reflect.Array in Java


• new operator vs newInstance()


• instanceof operator vs isInstance()�

File Handling

• File class


• Ways of Reading a text file in Java


• file permissions in java


• Moving a file from one directory to another using Java


• Copying file using FileStreams


• Delete a file using Java


• Java program to delete duplicate lines in text file


• Java program to merge two files alternatively into third file


• Java program to List all files in a directory and nested sub-directories | Recursive approach


• Java program to delete certain text from a file


• Check if a File is hidden in Java


• Redirecting System.out.println() output to a file

Java Tuple

• Introduction
  
• Unit Class in JavaTuples
  
• Pair Class in JavaTuples
  
• Triplet Class in JavaTuples
  
• Quartet Class in JavaTuples
  
• Quintet Class in JavaTuples
  
• Sextet Class in JavaTuples
  
• Septet Class in JavaTuples
  
• Octet Class in JavaTuples
  
• Ennead Class in JavaTuples
  
• Decade Class in JavaTuples
  
• LabelValue Class in JavaTuples
  
• KeyValue Class in JavaTuples
  
• Implement Pair Class with Unit Class in Java using JavaTuples
  
• Implement Quartet Class with Triplet Class in Java using JavaTuples
  
• Implement Triplet Class with Pair Class in Java using JavaTuples
  
• Implement Decade Class from Ennead Class in Java using JavaTuples
  
• Implement Ennead Class from Octet Class in Java using JavaTuples
  
• Implement Septet Class from Sextet Class in Java using JavaTuples
  
• Implement Octet Class from Septet Class in Java using JavaTuples
  
• Implement Sextet Class from Quintet Class in Java using JavaTuples
  
• Implement Quintet Class with Quartet Class in Java using JavaTuples
  

Useful and/or Advanced Features�

• Generics


• Wildcards in Java


• Assertions


• Annotations


• Serialization and Deserialization


• Lambda Expressions ? Java 8


• Stream


• BigInteger Class

Image Processing�

• Set 1 (Read and Write)


• Set 2 (Get and Set Pixels)


• Set 3 (Colored image to greyscale image conversion)


• Set 4 (Colored image to Negative image conversion)


• Set 5 (Colored to Red Green Blue Image Conversion)


• Set 6 (Colored image to Sepia image conversion)


• �Set 7 (Creating a random pixel image)


• Image Processing in Java | Set 8 (Creating mirror image)


• Set 9 ( Face Detection )


• Set 10 ( Watermarking an image )


• Set 11 (Changing orientation of image)


• Set 12 ( Contrast Enhancement )


• Set 13 (Brightness Enhancement)


• Set 14 ( Sharpness Enhancement )


• Set 14 ( Comparison of two images )


• Compressing and Decompressing files in Java

Networking in Java

• Socket Programming


• Introducing Threads in Socket Programming in Java


• URL class in Java


• HttpURLConnection Class


• Reading from a URL using URLConnection Class


• Inet Address Class


• MD2 Hash In Java
  
• SHA-1 Hash In Java
  
• SHA-224 Hash In Java
  
• SHA-256 Hash in Java
  
• SHA-384 Hash In Java
  
• SHA-512 Hash In Java
  

Java.Time Package

• Clock Class in Java


• Duration Class in Java


• Instant Class in Java


• LocalDate Class in Java


• LocalDateTime Class in Java


• LocalTime Class in Java


• MonthDay Class in Java


• Period Class in Java


• Year Class in Java


• YearMonth Class in Java


• ZonedDateTime Class in Java

Java.Lang Package

• Boolean Class in Java


• Byte Class in Java


• Character Class in Java


• Character.Subset Class in Java


• Character.UnicodeBlock Class in Java


• Class Class in Java Set 1, Set 2


• Compiler Class in Java


• Double Class in Java


• Enum Class in Java


• Float Class in Java


• InheritableThreadLocal Class in Java


• Integer Class in Java


• Long Class in Java


• Math Class in Java Set 1, Set 2


• Number Class in Java


• Object Class in Java


• Package Class in Java


• Process Class in Java


• ProcessBuilder Class in Java


• Runtime Class in Java


• Short Class in Java


• StackTraceElement Class in Java


• StrictMath Class in Java Set 1, Set 2


• String Class in Java Set 1, Set 2


• StringBuffer Class in Java


• StringBuilder Class in Java


• System Class in Java


• Thread Class in Java


• ThreadGroup Class in Java


• ThreadLocal Class in Java


• Throwable Class in Java


• Void Class in Java

Java.Math Package

• BigDecimal Class in Java


• BigInteger Class in Java

My Personal Notes
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