Java Programs

String

1. Count Number of Words in a String Java Program
2. Count Number of Times Each Character Appears in a String Java Program
3. Check if Given String or Number is a Palindrome Java Program
4. Java Program to Find The Longest Palindrome in a Given String
5. How to Reverse a String in Java
6. Reverse Each Word in a String Java Program
7. Check Given Strings Anagram or Not Java Program
8. Add Double Quotes to a String Java Program
9. Split a String Java Program
10. Find All Permutations of a Given String Java Program
11. If Given String Sub-Sequence of Another String in Java
12. Java Program to Find First Non-Repeated Character in a Given String
13. Find The First Repeated Character in a String Java Program
14. Find Duplicate Characters in a String With Repetition Count Java Program
15. Convert String to int in Java
16. Convert String to Byte Array Java Program
17. Convert String to float in Java
18. Convert String to double in Java
19. Convert Char to String And String to Char in Java
20. Convert String to Char Array in Java
21. Removing Spaces Between Words in a String Java Program

Numbers

1. Armstrong Number or Not Java Program
2. Java Program to Reverse a Number
3. Swap or Exchange Two Numbers Without Using Any Temporary Variable Java Program
4. Java Program to Check Prime Number
5. Java Program to Display Prime Numbers
6. Factorial Program in Java
7. Fibonacci Series Program in Java
8. Arrange Non-Negative Integers to Form Largest Number - Java Program
9. How to Display Pyramid Patterns in Java - Part1
10. How to Display Pyramid Patterns in Java - Part2
11. Convert int to String in Java
12. Convert float to String in Java
13. Convert double to String in Java
14. Convert float to int in Java
15. Convert double to int in Java
16. Convert Numbers to Words Java Program

Java - Array

1. Find Duplicate Elements in an Array Java Program
2. Remove Duplicate Elements From an Array in Java
3. How to Remove Elements From an Array Java Program
4. How to How to Find Common Elements Between Two Arrays Java Program
5. Find Largest and Second Largest Number in Given Array Java Program
6. Find Largest And Smallest Number in a Given Array Java Program
7. Array Rotation Java Program
8. Matrix Multiplication Java Program
9. Matrix Addition Java Program
10. Matrix Subtraction Java Program
11. Find Maximum And Minimum Numbers in a Given Matrix Java Program
12. Find The Maximum Element in Each Row of a Matrix Java Program

Java Date&Time

1. Format Date in Java Using SimpleDateFormat
2. How to Convert Date to String in Java
3. How to Convert String to Date in Java
4. How to Convert Date And Time Between Different Time-Zones in Java
5. How to Display Time in AM-PM Format in Java
6. Display Time in 24 Hours Format in Java
7. Difference Between Two Dates in Java
8. Compare Dates in Java
9. Create Date Object in Java With Date and Time Values
10. Java Program to Get Current Date and Time

Java - Collections

1. How to Iterate a HashMap of ArrayLists of String in Java
2. How to Sort Elements in Different Order in Java TreeSet

Lambda Expression

1. Java Lambda Expression Runnable Example
2. Java Lambda Expression Comparator Example
3. Java Lambda Expression Callable Example

Java Internals

1. How to Compile Java Program at Runtime
2. How to Run javap Programmatically From Java Program
3. Running Dos/Windows Commands From Java Program
4. How to Run a Shell Script From Java Program

Data Structures in Java

1. Linked List Implementation Java Program
2. Stack Implementation in Java Using Array
3. Stack Implementation in Java Using Linked List
4. Queue Implementation in Java Using Array
5. Queue Implementation in Java Using Linked List
6. Java Program to Detect And Remove Loop in a Linked List
7. How to Reverse a Linked List in Java
8. Sorted Linked List In Java
9. Doubly Linked List Implementation Java Program
10. Deque Implementation in Java Using Doubly Linked List
11. How to Reverse a Doubly Linked List in Java
12. Binary Tree Implementation in Java - Insertion, Traversal And Search
13. Java Program to Delete a Node From Binary Search Tree (BST)
14. Find Minimum and Maximum Value Nodes in Binary Search Tree - Java Program
15. Binary Tree Traversal Using Breadth First Search Java Program
16. Binary Tree Traversal Using Depth First Search Java Program

Java I/O

1. Reading File in Java Using BufferedReader
2. Reading File in Java Using Scanner
3. Reading Delimited File in Java Using Scanner
4. Reading File in Java Using Files.lines And Files.newBufferedReader
5. How to Read File From The Last Line in Java
6. How to Read Properties File in Java
7. How to Read Input From Console in Java
8. Read File Asynchronously Java Program
9. Write to a File in Java
10. Writing a File Asynchronously Java Program
11. How to Append to a File in Java
12. Read or List All Files in a Folder in Java
13. Java Program to Delete File And Directory Recursively
14. How to Find Last Modified Date of a File in Java
15. How to Count Lines in a File in Java
16. Java Program to Print Line Numbers With Lines in Java
17. Java Program to Convert a File to Byte Array
18. How to Read Excel File in Java Using Apache POI
19. How to Write Excel File in Java Using Apache POI
20. Creating Temporary File in Java

Compressing & Decompressing Files

1. Zipping Files And Folders in Java
2. Unzip File in Java
3. How to Create Password Protected Zip File in Java
4. Compress And Decompress File Using GZIP Format in Java
5. Creating Tar File And GZipping Multiple Files in Java
6. How to Untar a File in Java

Java Multi-Threading

1. Print Odd-Even Numbers Using Threads And wait-notify Java Program
2. Print Odd-Even Numbers Using Threads And Semaphore Java Program
3. Producer-Consumer Java Program Using wait notify
4. Producer-Consumer Java Program Using ArrayBlockingQueue
5. Producer-Consumer Java Program Using volatile
6. How to Run Threads in Sequence in Java
7. Printing Numbers in Sequence Using Threads Java Program
8. How to Create Deadlock in Java
9. Setting And Getting Thread Name And Thread ID in Java
10. Java Program to Create Your Own BlockingQueue

Java XML

1. How to Create PDF From XML Using Apache FOP

PDF Generation in Java

1. Creating PDF in Java Using iText
2. How to Create PDF in Java Using OpenPDF
3. Creating PDF in Java Using Apache PDFBox
4. HTML to PDF in Java + Flying Saucer and OpenPDF
5. Convert HTML to PDF in Java + Openhtmltopdf and PDFBox

Enum

1. Comparing Enum to String in Java
2. Converting String to Enum Type in Java
3. Converting Enum to String in Java

Java Reflection

1. Generating Getters And Setters Using Reflection in Java
2. Invoking Getters And Setters Using Reflection in Java

JDBC Programs

1. Connection Pooling Using Apache DBCP in Java
2. Connection Pooling Using C3P0 in Java
3. Java Program to Get All DB Schemas
4. Java Program to Get All The Tables in a DB Schema

Sorting Algorithms in Java

1. What is In-place Algorithm
2. Bubble Sort Program in Java
3. Selection Sort Program in Java
4. Insertion Sort Program in Java
5. Shell Sort Program in Java
6. Merge Sort Program in Java
7. Quick Sort Program in Java
8. Heap Sort Program in Java
9. Tree Sort in Java Using Binary Search Tree
10. Counting Sort Program in Java
11. Bucket Sort Program in Java
12. Radix Sort Program in Java

Searching Algorithms in Java

1. Linear Search (Sequential Search) Java Program
2. Binary Search Program in Java
3. Ternary Search Program in Java
4. Interpolation Search Program in Java
5. Exponential Search Program in Java

Java Basics Tutorial

Java, one of the most popular programming language, was conceived by James Gosling, Patrick Naughton, Chris Warth, Ed Frank, and Mike Sheridan at Sun Microsystems, Inc. in 1991. It was publicly released in 1995.

Java is an object oriented, high level language but what sets it apart is that Java is platform independent and it can run on a variety of platforms.

This Java beginners tutorial helps in understanding the basic concepts of Java programming language.

Java Getting Started

1. How to Install Java in Ubuntu
2. First Java Program - Hello World Java Program
3. Primitive Data Types in Java
4. Java Variable Types With Examples
5. Literals in Java
6. What Are JVM, JRE And JDK in Java
7. Java is a Strongly Typed Language

Operators in Java

1. Arithmetic And Unary Operators in Java
2. Equality And Relational Operators in Java
3. Conditional Operators in Java With Examples
4. Ternary Operator in Java With Examples
5. instanceof Operator in Java With Examples
6. Difference Between equals() Method And equality Operator == in Java

Conditional Statements & Loops in Java

1. if else Statement in Java With Examples
2. Switch Case Statement in Java With Examples
3. Switch Expressions in Java 12
4. Java for Loop With Examples
5. Java while Loop With Examples
6. Java do-while Loop With Examples
7. break Statement in Java With Examples
8. continue Statement in Java With Examples
9. return Statement in Java With Examples

Java Class And Object

1. Class in Java
2. Object in Java
3. Object Creation Using new Operator in Java
4. Object class in Java
5. Type Wrapper Classes in Java
6. Java Abstract Class and Abstract Method
7. Java Nested Class And Inner Class
8. Java Object Cloning - clone() Method
9. Shallow Copy And Deep Copy in Java Object Cloning

Java Constructor

1. Constructor in Java
2. Constructor Chaining in Java
3. Constructor Overloading in Java
4. Initializer Block in Java

Java Basics

1. Access Modifiers in Java - Public, Private, Protected and Default
2. Package in Java
3. Java Automatic Numeric Type Promotion
4. Why Class Name And File Name Should be Same in Java
5. Why main Method static in Java
6. Java Pass by Value or Pass by Reference
7. Java - Could not find or load main class error Fix
8. this Keyword in Java With Examples
9. super Keyword in Java With Examples
10. final Keyword in Java With Examples
11. strictfp in Java
12. finalize() Method in Java
13. Type Casting in Java With Conversion Examples
14. Why no Multiple Inheritance in Java

static in Java

1. static Keyword in Java With Examples
2. static Method Overloading or Overriding in Java
3. static Import in Java With Examples
4. static Reference to The Non-static Method or Field Error
5. static Block in Java

Array in Java

1. Array in Java With Examples

Java Math

1. BigDecimal in Java With Examples
2. BigInteger in Java With Examples

OOPS Concepts

1. Encapsulation in Java
2. Polymorphism in Java
3. Abstraction in Java
4. Inheritance in Java
5. Difference Between Encapsulation And Abstraction in Java
6. Method Overloading in Java
7. Method Overriding in Java
8. Association, Aggregation And Composition in Java

Interface in Java

1. Interface in Java With Examples
2. Marker Interface in Java
3. Difference Between Abstract Class And Interface in Java
4. Interface Default Methods in Java
5. Interface Static Methods in Java
6. Private Methods in Java Interface

String in Java

1. String in Java Tutorial
2. String Pool in Java
3. Why Java String is Immutable
4. Compact Strings in Java
5. Check String Null or Empty in Java
6. String Comparison in Java - compareTo(), equals()
7. Java String charAt() Method With Examples
8. Java String substring() Method - Getting Substring
9. Java String Search Using indexOf(), lastIndexOf() And contains() Methods
10. Java trim(), strip() - Removing Spaces From String
11. Java split() Method - Splitting a String
12. Java join() Method - Joining Strings
13. intern() Method in Java String
14. matches() method in Java String
15. StringJoiner Class in Java With Examples
16. StringBuffer Class in Java With Examples
17. StringBuilder Class in Java With Examples
18. String Vs StringBuffer Vs StringBuilder in Java
19. Is String Thread Safe in Java
20. How to Create Immutable Class in Java

Java Exception handling

1. Java Exception Handling Tutorial
2. try-catch Block in Java Exception Handling
3. finally Block in Java Exception Handling
4. Multiple Catch Blocks in Java Exception Handling
5. Nested Try Statements in Java Exception Handling
6. throw Statement in Java Exception Handling
7. throws Keyword in Java Exception Handling
8. Exception Propagation in Java Exception Handling
9. Java Exception Handling And Method Overriding
10. Difference Between Checked And Unchecked Exceptions in Java
11. Difference Between throw And throws in Java
12. final Vs finally Vs finalize in Java
13. Creating Custom Exception Class in Java
14. Multi-Catch Statement in Java Exception Handling
15. Try-With-Resources in Java With Examples
16. Best Practices For Exception Handling in Java
17. java.lang.ClassNotFoundException - Resolving ClassNotFoundException in Java
18. java.lang.ClassCastException - Resolving ClassCastException in Java
19. java.lang.UnsupportedClassVersionError - Resolving UnsupportedClassVersionError in Java
20. Difference Between StackOverflowError and OutOfMemoryError in Java

Java Advanced Topics

Java Collection Framework

List

1. ArrayList in Java With Examples
2. How ArrayList Works Internally in Java
3. Unmodifiable or Immutable List in Java
4. How to Loop or Iterate an Arraylist in Java
5. ListIterator in Java
6. How to Join Lists in Java
7. How to Remove Elements From an ArrayList in Java
8. How to Remove Duplicate Elements From an ArrayList in Java
9. How to Sort ArrayList in Java
10. How to Sort ArrayList of Custom Objects in Java
11. How to Sort an ArrayList in Descending Order in Java
12. How and Why to Synchronize ArrayList in Java
13. How to Convert ArrayList to Array in Java
14. How to Convert Array to ArrayList in Java
15. How LinkedList Class Works Internally in Java
16. Difference Between ArrayList And LinkedList in Java
17. Difference Between ArrayList And Vector in Java
18. Difference Between Array And ArrayList in Java
19. Difference Between ArrayList And CopyOnWriteArrayList in Java

Map

1. HashMap in Java With Examples
2. How HashMap Works Internally in Java
3. Map.Entry Interface in Java
4. Unmodifiable or Immutable Map in Java
5. How to Loop Through a Map in Java
6. How to Sort a HashMap in Java
7. How to Remove Entry From HashMap in Java
8. LinkedHashMap in Java With Examples
9. TreeMap in Java With Examples
10. Difference Between HashMap And Hashtable in Java
11. HashMap Vs LinkedHashMap Vs TreeMap in Java
12. Difference Between HashMap And ConcurrentHashMap in Java
13. Java Map compute() With Examples
14. Java Map computeIfPresent() With Examples
15. Java Map computeIfAbsent() With Examples
16. Java Map containsKey() - Check if Key Exists in Map
17. Java Map containsValue() - Check if Value Exists in Map
18. Java Map getOrDefault() Method With Examples
19. Java Map merge() With Examples
20. Java Map putIfAbsent() With Examples
21. Java Map replace() With Examples
22. Java Map size() With Examples

Set

1. HashSet in Java With Examples
2. How HashSet Works Internally in Java
3. Unmodifiable or Immutable Set in Java
4. How to Loop Through HashSet in Java
5. LinkedHashSet in Java With Examples
6. TreeSet in Java With Examples
7. EnumSet in Java With Examples
8. How to Sort HashSet in Java
9. HashSet Vs LinkedHashSet Vs TreeSet in Java
10. How to Sort Elements in Different Order in TreeSet

General

1. equals() And hashCode() Methods in Java
2. Fail-Fast Vs Fail-Safe Iterator in Java
3. Difference Between Comparable and Comparator in Java
4. removeIf() Method in Java Collection With Examples

Java Collections Interview Questions

1. Java Collections Interview Questions And Answers

Java Concurrent utilities

Synchronization utilities

1. Java CountDownLatch With Examples
2. Java CyclicBarrier With Examples
3. Difference Between CountDownLatch And CyclicBarrier in Java
4. Java Phaser With Examples
5. Java Exchanger With Examples
6. Java Semaphore With Examples

Locks

1. Java ReentrantLock With Examples
2. Difference Between ReentrantLock And Synchronized in Java
3. Java ReentrantReadWriteLock With Examples
4. Java StampedLock With Examples

Concurrent Collections

1. ConcurrentHashMap in Java With Examples
2. Difference Between HashMap And ConcurrentHashMap in Java
3. CopyOnWriteArrayList in Java With Examples
4. Difference Between ArrayList And CopyOnWriteArrayList in Java
5. CopyOnWriteArraySet in Java With Examples
6. ConcurrentSkipListMap in Java With Examples
7. ConcurrentSkipListSet in Java With Examples
8. ConcurrentLinkedQueue in Java With Examples
9. ConcurrentLinkedDeque in Java With Examples

BlockingQueue

1. Java BlockingQueue With Examples
2. Java ArrayBlockingQueue With Examples
3. Java LinkedBlockingQueue With Examples
4. Java PriorityBlockingQueue With Examples
5. Java SynchronousQueue With Examples
6. Java DelayQueue With Examples
7. Java LinkedTransferQueue With Examples

BlockingDeque

1. Java BlockingDeque With Examples
2. Java LinkedBlockingDeque With Examples

Executors

1. Callable and Future in Java With Examples
2. Difference Between Runnable And Callable in Java
3. Executor And ExecutorService in Java With Examples
4. Java ThreadPoolExecutor - Thread Pooling With ExecutorService
5. Java ScheduledThreadPoolExecutor - Task Scheduling in Java
6. CompletableFuture in Java With Examples

Atomic variables

1. AtomicInteger in Java With Examples
2. AtomicLong in Java With Examples

Concurrency concepts

1. Lock Striping in Java Concurrency
2. Non-Blocking Algorithms
3. Busy Spinning in Multi-Threading
4. Blocking Methods in Java Concurrency

Java Concurrency Interview Questions

1. Java Concurrency Interview Questions And Answers

Reflection API in Java

1. Java Reflection API Tutorial
2. Reflection in Java - Getting Class Information
3. Reflection in Java - Getting Field Information
4. Reflection in Java - Getting Method Information
5. Reflection in Java - Getting Constructor Information
6. Reflection in Java - Array
7. Generating Getters And Setters Using Reflection - Java Program
8. Invoking Getters And Setters Using Reflection - Java Program
9. Invoke Method at Runtime Using Java Reflection API

Java-JDBC

1. JDBC Tutorial - Java JDBC Overview
2. Types of JDBC Drivers
3. Java JDBC Steps to Connect to DB
4. Connection Interface in Java-JDBC
5. Statement Interface in Java-JDBC
6. ResultSet Interface in Java-JDBC
7. PreparedStatement Interface in Java-JDBC
8. CallableStatement Interface in Java-JDBC
9. DataSource in Java-JDBC
10. DatabaseMetaData Interface in Java-JDBC
11. Transaction Management in Java-JDBC
12. Batch Processing in Java JDBC - Insert, Update Queries as a Batch
13. How to Get The Inserted ID (Generated ID) in JDBC

Serialization in Java

1. Serialization and Deserialization in Java
2. Transient Keyword in Java With Examples
3. Externalizable Interface in Java
4. SerialVersionUID And Versioning in Java Serialization
5. Serialization Proxy Pattern in Java

Java Multi-Threading

1. Java Multithreading Tutorial
2. Creating a Thread in Java
3. Thread States (Thread Life Cycle) in Java Multi-Threading
4. Thread Priority in Java Multi-Threading
5. Difference Between Thread And Process in Java
6. Main Thread in Java
7. Can we Start The Same Thread Twice in Java
8. What if run() Method Called Directly Instead of start() Method - Java Multi-Threading
9. Synchronization in Java - Synchronized Method And Block
10. Static Synchronization in Java Multi-Threading
11. Race Condition in Java Multi-Threading
12. Deadlock in Java Multi-Threading
13. Thread Starvation in Java Multi-Threading
14. Livelock in Java Multi-Threading
15. Inter-thread Communication Using wait(), notify() And notifyAll() in Java
16. Why wait(), notify() And notifyAll() Methods Are in Object Class And Not in Thread Class
17. Why wait(), notify() And notifyAll() Must be Called Inside a Synchronized Method or Block
18. isAlive() And join() Methods in Java Multi-Threading
19. Difference Between yield And sleep in Java Multi-Threading
20. Difference Between sleep And wait in Java Multi-Threading
21. Java ThreadLocal Class With Examples
22. Volatile Keyword in Java With Examples
23. String And Thread-Safety in Java

Java Multi-Threading Interview Questions

1. Java Multithreading Interview Questions And Answers

Java 5 Features

1. Varargs (Variable-length Arguments) in Java
2. Enum Type in Java
3. AutoBoxing And UnBoxing in Java
4. Covariant Return Type in Java

Generics in Java

1. Generics in Java
2. Generic Class, Interface And Generic Method in Java
3. Bounded Type Parameter in Java Generics
4. Wildcard in Java Generics
5. Type Erasure in Java Generics

Java 8 Features

1. Interface Default Methods in Java 8
2. Interface Static Methods in Java 8
3. New Date And Time API in Java 8
4. Optional Class in Java With Examples
5. Effectively Final in Java 8
6. forEach Statement in Java 8
7. PermGen Space Removal in Java 8
8. StringJoiner Class in Java 8

Lambda Expressions - Java 8

1. Lambda Expressions in Java 8
2. Lambda Expression Examples in Java
3. Functional Interfaces in Java
4. @FunctionalInterface Annotation in Java
5. Pre-defined Functional Interfaces in Java
6. Java Lambda Expression as Method Parameter
7. Java Lambda Expression And Variable Scope
8. Exception Handling in Java Lambda Expressions
9. Method Reference in Java
10. How to Fix The Target Type of This Expression Must be a Functional Interface Error
11. How to Resolve Local Variable Defined in an Enclosing Scope Must be Final or Effectively Final Error

Stream API - Java 8

1. Java Stream API Tutorial
2. Java Stream API Examples
3. Primitive Type Streams in Java Stream API
4. Parallel Stream in Java Stream API
5. Reduction Operations in Java Stream API
6. Map Operation in Java Stream API
7. collect() Method And Collectors Class in Java Stream API
8. Java Stream - allMatch() With Examples
9. Java Stream - anyMatch() With Examples
10. Java Stream - boxed() With Examples
11. Java Stream - concat() With Examples
12. Java Stream - count() With Examples
13. Java Stream - Collectors.groupingBy() With Examples
14. Java Stream - Collectors.joining() With Examples
15. Java Stream - Collectors.partitioningBy() With Examples
16. Java Stream - Collectors.summingInt(), summingLong(), summingDouble()
17. Java Stream - Collectors.averagingInt(), averagingLong(), averagingDouble()
18. Java Stream - Collectors.teeing() With Examples
19. Java Stream - distinct() With Examples
20. Java Stream - filter() With Examples
21. Java Stream - findAny() With Examples
22. Java Stream - findFirst() With Examples
23. Java Stream - flatMap() With Examples
24. Java Stream - limit() With Examples
25. Java Stream - max() With Examples
26. Java Stream - min() With Examples
27. Java Stream - noneMatch() With Examples
28. Java Stream - peek() With Examples
29. Java Stream - skip() With Examples
30. Java Stream - sorted() With Examples
31. Java Stream - Convert Stream to List
32. Java Stream - Convert Stream to Set
33. Java Stream - Convert Stream to Map
34. Java Stream - Convert Stream to Array
35. Spliterator in Java

Java 9 Features

1. JShell in Java With Examples
2. Private Methods in Java Interface

Java 10 Features

1. Var type in Java - Local Variable Type Inference

Java 16 Features

1. Java Record Class With Examples

Java 17 Features

1. Java Sealed Classes and Interfaces

Eclipse IDE

1. How to Pass Command Line Arguments in Eclipse
2. Creating a Maven Project in Eclipse
3. Adding Tomcat Server to Eclipse

Java Internals

1. Just In Time Compiler (JIT) in Java
2. JVM Run-Time Data Areas - Java Memory Allocation
3. Heap Memory Allocation in Java
4. Garbage Collection in Java
5. PermGen Space Removal in Java 8

Java IO

1. Byte Streams in Java IO
2. Character Streams in Java IO
3. Buffered Streams in Java IO
4. getPath(), getCanonicalPath() and getAbsolutePath() Methods in Java
5. Java BufferedReader Class With Examples
6. Java BufferedWriter Class With Examples
7. Fix Scanner.nextLine() Skipping Input After Another next Methods