Core Java Beginner Tutorials:

Number System Problems:

• Swap two numbers in java using third or temporary variable (example)
• Reverse number – Leet Code Challenge
• Program to convert binary number to decimal (java api, iterative & recursive)
• Program to check given input number is even or odd in java (example)
• Convert decimal to hexadecimal – java api, iterative & recursive
• Convert hexadecimal to decimal – java api, iterative & recursive
• Find factorial of number in java – recursive & iterative (example)
• Find LCM of two numbers using GCD in java (example)
• Find number of consecutive 1’s in a binary number in java (example)
• Find sum of all digits of given number/Integer (java /example)
• GCD of two numbers Euclidean algorithm in java (iterative/ recursive)
• Generate/ print fibonacci series in java – recursive & iterative (example)
• Program to calculate simple interest (Java & Example)
• Convert decimal number to Octal – (java api, iterative & recursive)
• Convert decimal number to hexdecimal – (java api, iterative & recursive)
• Convert decimal number to binary – (java api, iterative & recursive)
• Check whether given integer number is prime or not in java (example)
• Check integer number is positive, negative, zero in java (example)
• Check given number is palindrome using java (non-recursive/example)
• Calculate power of integer number in java (example)
• Swap two numbers without using third or temporary variable in java
• Program to add two binary numbers in java (example)

String Manipulation Problems:

• Program to convert String to Double in java (example)
• Program to convert String to Float in java (example)
• Convert String variable to Long in java (example)
• Program to print duplicate characters in String (Java8 /Example)
• Program to convert char to string in java (Character, String class)
• Program to convert String to char & char array in java
• Program to convert char array to string (Java Stream, StringBuilder, String)
• Convert String variable to Integer in java (example)
• Convert String object to lower case & upper case in java (example)
• Reverse each word of a string using StringBuilder in java (example)
• Reverse string word by word in java (stack/ stringbuilder /example)
• Java API, recursive & iterative algorithm to reverse string (example)
• Join or concatenate or combine multiple strings in java (example)
• Program to count & print vowels, consonant in String (java /example)
• Program to sort array of strings – Java 8 Lambda Stream

Basic Geometry Problems:

• Find area & perimeter of a square in java (with example)
• Find area of triangle (three sides) using hero formula ( java & example)
• Find area of triangle using base & height in java (example)
• Find area & perimeter of rectangle in java (with example)
• Given radius, find area & circumference of circle in java (example)

Beginner Problems

• Create or implement FizzBuzz game program in java (with example)
• Write or redirect console output to a file & again reset to standard output in java
• Write or redirect standard output error stream to a file in java

What’s new in Java?

• Key Features & Enhancements in Java Versions (Release wise)
• Comprehensive Guide: Exploring the Exciting New Features of Java 17

Java 8 – Tutorials:

• Read a file line by line using java 8 lambda stream
• Java 8 Functional interface explained with examples (Comparator)
• Create Runnable task using functional interface 
• Impact of interface’s default method on multiple inheritance
• Join or combine two / multiple Strings using StringJoiner
• Find object from ArrayList of objects using lambda stream
• Search String in ArrayList collection – stream lambda
• Sort objects on multiple fields /properties – Comparator interface (lambda stream)
• Filter/Remove null & empty string from Array – lambda stream
• Filter/remove null element/String from ArrayList of objects – lambda stream
• Convert heterogeneous object into another – stream lambda
• Convert list of objects to /from map in java 8 lambda stream
• groupBy, mapping & statistics features in Java8 lambda stream
• Primitive streams example in java8 (IntStream, LongStream, DoubleStream)

Java Concurrency Framework Tutorials:

Threads Basics

• What are threads (Real world analogy) ?
• Create threads using runnable interface & thread class
• Create runnable task using functional interface
• Thread join example using Runnable interface in java

Thread Pools:

• Create fixed thread pool in java using Executors
• Create single thread pool using executor in java 
• Create custom thread pool in java without executor framework

Thread Synchronization:

• Producer & Consumer (Wait notify example)
•  Deadlock in multi-threading (concurrency)
• CountDownLatch
• Synchronize resources using Semaphore
• Synchronize resources using ReentrantLock 
• Inter thread communication in java (PipedInputStream /PipedOutputStream)

Java Exception and Error Tutorials:

• What is difference between error & exception in java ?
• What is difference between throw, throws & Throwable in java ?
• Generate Out of memory error in java
• Difference between checked & unchecked exception (class hierarchy)
• Simulate unchecked exceptions in java
• try with resources & AutoCloseable java 7
• Catch multiple exceptions before & after java 7
• Create custom or user defined unchecked exception 
• User defined custom Runtime/Unchecked exception

Java Security:

• Configured JCA/JCE Provider execution order (Java Security)
• List configured JCE/JCA Providers in Java Runtime (Security)
• Install Bouncy Castle Provider by configuring Java Runtime
• Base64 Encode decode URL/URI string in Java 8
• Base64 withoutPadding Encoding of string or byte array (Java8)
• Base64 Encode & Decode of password string or byte array (Java8)
• Encrypt Decrypt message using AES-128 CBC in java (with example)

Java File Input Output (IO) operations:

Basic File IO Operations

• Create new file & directory
• Create temporary file
• Recursively list all files present in directory
• List all directories of input path using scope operator & file filter in java
• Recursively list all files & folders of input directory
• Read file line by line using java 8 lambda stream
• Convert local file path to URL & URI
• Check read, write, execute permission & hidden attribute of file
• List system drive & their total, free, used space
• Write standard output error stream to a file in java
• Write console output to a file & again reset to standard output in java

Scanner Class:

• Read user inputs from command line (Scanner class)
• Read & write contents from/to file

Zip & Unzip file

• Zip contents of directory
• Zip contents of directory & sub-directories recursively
• List contents of compressed or zipped file

BufferReader & BufferWriter

• Read write file
• Read & write file using Non Blocking IO
• Read & Write UTF contents
• Read & write UTF file using (Non Blocking IO)

InputStreamReader & OutputStreamWriter:

• Read & write file
• Read write UTF contents

FileInputStream & FileOutputStream

• Read & write file
• Write java properties to file

Other File Streams:

• Read & Write file using CharArrayReader & CharArrayWriter
• File read write IO operation using StringWriter & StringReader
• Write file using PrintWriter
• Inter thread communication using PipedInputStream & PipedOutputStream

Java Reflection Tutorials:

• Get all fields or data members of class
• List all methods or functions of class
• Print public/protected/private constructors of class
• List public methods or functions of class
• Find out class name of an object at Runtime 
• Find type of objects at Runtime using instanceof operator
• Create object or instance of class by name using Class.forName