Java Tutorial

Java Tutorial Java Features C++ vs Java Java History Java Hello World Java Development Kit Java Runtime Environment Java Virtual Machine Difference between JDK, JRE, and JVM Memory Areas in Java Java Operators Java Keywords Primitive Data Types Variables

Java Loops

Java Do While Loop Java While Loop Java For Loop Java Enhanced For Loop

Java Programs

Java Basic Programs Factorial Program in Java Fibonacci Series Program in Java Prime Number Program in Java Palindrome Number Program in Java Armstrong Number Program in Java Anagram Program in Java Pattern Programs in Java Calculator Program in Java Leap Year Program in Java Addition Program in Java Number Pattern Programs in Java Star Pattern Programs in Java Package Program in Java Pyramid Program in Java Sorting Program in Java String Palindrome Program in Java Even Odd Program in Java For Loop Program in Java If Else Program in Java Switch Case Program in Java GCD Program in Java LCM Program in Java Hello Program in Java Matrix Program in Java Menu Driven Program in Java Series Program in Java Client Server Program in Java Swapping Program in Java Pig Latin Program in Java Tower of Hanoi Program in Java Recursion Program in Java Matrix Multiplication Program in Java Perfect Number Program in Java Classes and Objects in Java Example Programs String Programs in Java Array Programs in Java Constructor Program in Java Inheritance Program in Java Abstract class Program in Java Interface Program in Java Encapsulation Program in Java Polymorphism Program in Java Exception Handling Program in Java Multithreading Program in Java Thread Program in Java Collection Programs in Java ArrayList Program in Java Stack Program in Java Applet Program in Java Swing Program in Java JDBC Program in Java How to run Java program in command prompt How to run Java program in Eclipse Program to find and replace characters on string in java Program to find the duplicate characters in a string Program to check whether a given character is present in a string or not Java Program to Print Permutations of String Java program to find frequency of characters in a string Java Program to remove duplicate characters in a string

Java Sorting

Sorting Algorithms in Java Merge Sort in Java Quick Sort in Java Bubble Sort in Java Insertion Sort in Java Selection Sort in Java Heap Sort in Java Radix Sort in Java Topological Sort in Java Bucket Sort in Java Counting Sort in Java

Java OOPs Concepts

OOPs - Object Oriented Programming Objects and Classes in Java Methods in Java Java Naming Conventions Constructors in Java Java this keyword Java static keyword Inheritance in Java Aggregation in Java Java super keyword Constructor Chaining and Constructor Overloading Java Polymorphism Static and Dynamic Binding in Java Java Abstraction Abstract class in Java Interface in Java Difference between Abstract class and Interface Java final keyword Packages in Java Access Modifiers in Java Java Wrapper classes Java Numbers Java Characters Java Integer Java Boolean Java Arrays Java Command Line Arguments Java strictfp Keyword Java Math

Java Strings

Java Strings Java String Methods StringBuilder in Java StringBuffer in Java Java Regular Expressions StringBuffer vs StringBuilder String vs StringBuffer String vs StringBuilder String Manipulation in Java Java String Concatenation How to Reverse a String in Java String Array in Java How to Compare Two Strings in Java How to Concatenate Two Strings in Java Why String in Immutable in Java Java.lang.NumberFormatException for Input String String Pool in Java Java Generate Random String How to take String Input in Java Java String Interview Questions

Java Exceptions

Exception Handling in Java Java try catch Java throw Java throws Difference between throw and throws Java finally Java Custom Exception Java Exception Propagation

Garbage Collection

Automatic Resource Management in Java Java Garbage Collection Java finalize() Java gc() Difference between final, finally and finalize


Multithreading in Java Process and Thread in Java Basic Terms in Multithreading Java Thread creation Thread Scheduler in Java Java Thread class DeadLock in Java

Java IO

Java IO Java Read File Java file Reader Java Buffer Reader Java file Writer Java BufferedWriter Java InputStreamReader Scanner in Java Java StringReader Java StringReader Class Java PrintWriter Java File Java Read File Line By Line Java FileInputStream Java FileOutputStream Java Create File Java Delete File Java Open File Java Read File to String Java copy file Java Read JSON file Jar File in Java Java FileNotFoundException


Java Serialization Java transient


Java Network Programming Java Socket Programming Java URL Java URLConnection HttpURLConnection in Java Java InetAddress Java DatagramSocket and Java DatagramPacket


Java AWT


Swing in Java

Java Collections

Collections in Java Java List Interface ArrayList in Java LinkedList in Java Vector in Java Stack in Java ArrayList vs LinkedList in Java ArrayList vs Vector in Java Java Set Interface HashSet in Java LinkedHashSet in Java TreeSet in Java Java Queue Interface PriorityQueue in Java ArrayDeque in Java Java Map Interface HashMap in Java LinkedHashMap in Java TreeMap in Java Dictionary in Java Hashtable in Java Properties in Java Collections class in Java Java Comparable Java Comparator Comparable vs Comparator in Java

Java Generics

Generics in Java

Java Annotations

Annotations in Java


Java JDBC Tutorial JDBC Architecture Types of JDBC Drivers JDBC vs ODBC Java Database Connectivity with MySQL Statements in java Prepared statement in Java Resultset in java Java ResultSetMetaData DatabaseMetaData in Java Callable Statement in Java Transaction Management in java Design of JDBC

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Java float vs double Java vs Scala Static vs Non-static in Java C vs Java int vs Integer in Java Java protected vs private Java vs Dot Net Stack vs Heap in Java Java Array vs ArrayList Java SE vs EE Difference between = = and equals ( ) in java Difference between C, C++, java

How to

How to run Java program How to set path in Java How to check the Java version in cmd How to install Java in Windows 10 How to run Java program in cmd How to add double quotes in a string in Java How to convert list to String in Java How to call a method in Java How to sort an array in Java How to iterate HashMap in Java How to write Java program How to create an array in Java How to create a package in Java How to generate random numbers in Java How to input String in Java How to create thread in Java How to find length of String in Java How to sort a string in Java How to use scanner in Java How to achieve multiple inheritance in Java How to find the length of an Array in Java How to run Java program in Eclipse How to call a function in Java How to create array of objects in Java How to create custom exception in Java How to import packages in Java How to run applet Program in Java How to take Array Input in Java How to achieve abstraction in Java How to call static method in Java How to compare characters in Java How to compare dates in Java How to create a linked list in Java How to get ASCII value of char in Java How to initialize string array in Java How to Install Java on MAC How to run java program in ubuntu How to find characters with the maximum number of times in a string java How to Set Java_home in Linux How to Split the String in Java with Delimiter How to uninstall the Java in Ubuntu How to Split String by Comma in Java How to remove special characters from String in Java How to remove last character from String in Java

Java 8 Features

Java 8 Features Lambda Expressions in Java Functional Interface in Java Streams in Java Java Base64 Encoding and Decoding Java Stringjoiner Class Parallel Arrays Sort in Java

Java 9 Features

Java 9 Tutorial Java 9 Try With Resources Java 9 Interface Private Method

Java 16

Java 16

Java 17

What is new in Java 17

Java Servlet Tutorial

Java Servlets Tutorial

Java JSP Tutorial

Java JSP Tutorial

Hibernate Tutorial

Hibernate Tutorial

Spring Tutorial

Spring Tutorial

Spring MVC Tutorial

Spring MVC Tutorial

Jenkins Tutorial

Jenkins Tutorial

Java Math Methods

Math.abs() Math.acos() Math.addExact() Math.asin() Math.atan () Math.atan2() Math.cbrt() Math.ceil() Math.copysign() Math.cos() Math.cosh() Math.decrementExact() Math.exp() Math.expm1() Math.floor() Math.floorDiv() Math.floorMod() Math.fma() Math.getExponent() Math.hypot() Math.IEEEremainder() Math.incrementExact() Math.log() Math.log10() Math.log1p() Math.max() Math.min() Math.multiplyExact() Math.multiplyFull() Math.negateExact() Math.nextAfter() Math.nextDown() Math.nextUp() Math.pow() Math.random() Math.rint() Math.round() Math.scalb() Math.signum() Math.sin() Math.sinh() Math.sqrt() Math.subtractExact() Math.tan() Math.tanh() Math.toDegrees() Math.toIntExact() Math.toRadians() Math.ulp()

Java String Methods

toCharArray() copyValueOf() endsWith() equals() equalsIgnoreCase() format() getBytes() getChars() hashCode() indexOf() intern() isEmpty() join() lastIndexOf() length() replace() replaceAll() replaceFirst() split() startsWith() subSequence() substring() toLowerCase() toUpperCase() trim() valueOf()

Java Conversion

Java Convert String to int Java Convert int to String Java Convert String to long Java Convert long to String Java Convert String to float Java Convert float to String Java Convert String to double Java Convert double to String Java Convert String to Date Java Convert Date to String Java Convert String to Object Java Convert Object to String Java Convert String to char Java Convert char to String Java Convert int to long Java Convert long to int


Functional Interfaces in Java Singleton class in Java Awesome explanation of Strings in Java Object class in Java Static class in Java All the important string methods in Java String Handling Method in Java What are Array strings in Java Advantages and Disadvantages of Strings in Java Big Decimal class in Java Class definition in Java Char and String differences in Java Difference between String, StringBuffer and StringBuilder in java Replace character in string Java String Coding Interview Questions in Java What is String in Java? String isnullorempty in Java String Matches in Java Trim Method in String Java Bean class in Java Libraries in Java Arithmetic Operations on String in Java Convert Char array to string in java Check whether Java is installed or not How to calculate time difference in Java How to stop execution after a certain time in Java Jagged Array in Java Java ArraylistRemove() Time Complexity Java Swing Time Picker Zigzag Array in Java Array and String based questions in Java Array and String with Examples in Java Best Practices to use String Class in Java What is string in Java why it's immutable Java String Java String Inbuilt functions Java String Matches vs Contains Sum of digits in string in java Check the presence of Substring in a String in java Java import packages Interfaces and Classes in Strings in Java Maximum length of string in java Hidden classes in Java Class memory in Java public static void main string args meaning in java Reverse a String in Java String Concatenation in Java Difference between String and Char Array in Java Buffer reader to read string in Java Split String into String Array in Java Reverse a String using Collections in Java Upcasting and Downcasting in Java String Declaration in Java Method Overloading In Java Java Solid Principles Java Architecture Binary Search Java Star Program in Java Java Type Casting Java Pass-by-Reference Java Framework List Java Destructors Java Control Statements Java Byte Code Java Beans Java Identifiers Character Array in Java Java Applications Java Substring Java Session Non-primitive data types in Java Matrix Multiplication in Java JIT in Java Java Tokens Java Externalization Default Virtual Behaviour in C++ vs Java Why we use static in Java Session Tracking in Java Knapsack problem in Java Java Logo Java exception list Java Iterator Java instance variable Frugal number in Java Fork Join in Java Date time API in java Compile time vs Runtime in java Compare time in java AES 256 Encryption in Java Advanced Java skills What is advance Java? User Defined Exception in Java Upcasting in Java Tree Implementation in Java Special Operators in Java Reentrant Lock in Java Perfect Number in Java Java logger Java LinkedList vs ArrayList File Operation in Java Differences between Byte Code and Machine Code Difference between String Tokenizer and split Method in Java Difference between JIT and JVM in Java Constructor Overloading in Java Conditional operator in Java Concurrent Linked Deque in Java with Examples Command Class in Java Java Break Keyword Best Java IDE Association in Java Access specifiers in Java

Java 16

Java 16 is the most recent short-term incremental release, based on Java 15, and it was released on March 16, 2021. Records and sealed classes are just two of the unique features included in this release.

There are two new changes in jdk16.

ZGC (concurrent thread stack processing) JEP 376:

It increases the z garbage collector capacity by moving the thread stack processing from the safe point to the concurrent phase.

Even on a larger heap, it allows a sub milliseconds pause on GC safe points.

Elastic metaspace (JEP 387)

Another change is from the memory management for meta space. Earlier, when

the memory was not required, the unused space was returned to JVM, but the

space was not returned to OS by JVM. Because of this, class loader overhead and

fragmentation would be. Now in Java 16, this problem was resolved by JVM

returning data to OS, and now even the memory in small chunks is not wasted

and is allocated, which leads to reducing the overhead and fragmentation.

Features of java 16 include:

Warnings for Value-based classes proposal:

The warnings for value-based classes proposal classifies the primitive wrapper classes as value-based; hence, their constructors are deprecated for removal, leading to new deprecation warnings. Warnings are displayed when improper synchronization attempts are attempted on instances of any value-based classes on the Java platform. The Valhalla Project, which seeks to introduce primitive classes as a significant improvement to the Java programming model, is the driving force behind this endeavour. Primitive classes claim that instances are identity-free, capable of inline or flattened representations, and freely copyable between memory regions. Instances are also encoded using the values of their fields. Since Java's primitive class concept and implementation have reached a certain level of maturity, it is possible to anticipate that in a future release, some Java platform classes will be converted to primitive classes. Informally referred to as value-based classes in API specifications, migration candidates.

Sealed classes:

The ability of other classes and interfaces to extend or implement sealed classes and interfaces is constrained. They have first introduced in JDK 15 and then again in JDK 16. The goal of the plan is to provide the author of a class or interface control over the code that implements it, provide a declarative technique to limit the use of a superclass other than access modifiers, and pave the way for future advances in pattern matching by setting up pattern analysis.

Strong encapsulation:

JDK internals is, by default, strongly encapsulated, with the exception of several crucial internal APIs, such misc. Unsafe. Users have access to the relaxed, strong encapsulation option, which has been the standard since JDK 9. This proposal, which is a part of Project Jigsaw, aims to improve the security and maintainability of the JDK and encourage programmers to utilize standard APIs instead of internal ones so that programmers and end users may quickly update to new Java releases. The primary threat to this plan is that existing Java programmes won't execute. When standard substitutes are available, developers are urged to utilize the jdeps tool to find code that depends on JDK internal components. Developers can test existing code using an existing release, such as JDK 11, by testing with —illegal-access=deny, —illegal-access=debug, and —illegal-access=warn to discover internal items accessed via reflection.

Foreign API linker:

Using a pure-Java, statically typed linker API, access to native code is possible. This is the incubator stage of this API in JDK 16. The proposed foreign-memory access API should be used in conjunction with the foreign linker API to greatly reduce error-prone native library binding. This strategy aims to replace JNI (Java Native Interface) with a superior pure-Java development paradigm, support C, and eventually be adaptable enough to handle new platforms, like 32-bit x86, and foreign functions written in languages other than C, including C++. Performance ought to surpass or be on par with JNI.

Z Garbage collector:

Concurrently processing the thread-stack processing of the ZGC (Z Garbage Collector) from safe locations. With this strategy, thread-stack processing from ZGC safe points will be eliminated, stack processing will be made lazy, cooperative, concurrent, and incremental, all other per-thread root processing from ZGC safe points will be eliminated, and other HotSpot VM subsystems will be given a way to lazily process stacks. With ZGC, HotSpot GC pauses, and scaling problems should become a thing of the past. Up to this point, GC activities that scale with the size of the heap and the size of the meta space have been transferred from safe point operations to concurrent phases. These have included the majority of root processing, marking, relocation, reference processing, and class unloading. Only a portion of root processing and a time-limited marking termination operation are still carried out in GC safe points. These thread roots, which have the drawback of scaling with the number of threads, include Java thread stacks and other thread roots. Per-thread processing, including stack scanning, has to be moved to a concurrent phase to improve the problem. The time spent inside ZGC safe points on common machines should be less than one millisecond using this strategy, and the throughput penalty of the improved latency should be negligible.

Elastic meta space capability:

To save maintenance costs, an elastic meta space capability returns unused HotSpot VM class metadata (meta space) RAM to the OS more quickly and reduces the meta space footprint. There have been difficulties with Meta space’s significant off-heap memory usage. The strategy calls for swapping out the current memory allocator for a buddy-based allocation technique that offers an algorithm to partition memory to accommodate memory requests. This method, which has been applied in the Linux kernel, will enable memory to be allocated in more manageable chunks, lowering class-loader overhead. Fragmentation will be lessened as well. To minimize the footprint for loaders that begin with huge arenas but do not utilize them right away or may not use them to their full potential, the OS memory commitment to memory management arenas will also be carried out slowly, only when necessary. Meta space memory will be divided into equally sized granules that can be committed and uncommitted independently of one another to fully utilize the elasticity provided by buddy allocation.

Enabling C++ 14 features:

Enabling C++ 14 language features will make it possible for JDK C++ source code to leverage C++ 14 capabilities and will provide precise instructions on which features may be used in HotSpot VM code. The language capabilities available to C++ code in the JDK up until JDK 15 were restricted to the C++98/03 language standards. The source code was updated to support building with more recent iterations of the C++ standard with JDK 11. This includes having access to the latest compilers that support the C++ 11/14 language features while building. For C++ code used outside of HotSpot, no style or usage modifications are suggested by this proposal. However, depending on the platform compiler, some build-time adjustments may be necessary to utilize C++ language capabilities.

Incubator stage of vector API:

A vector API that is currently in the incubator stage and uses the JDK's incubator module, jdk.incubator.vector, to define vector computations that compile to the best possible vector hardware instructions on supported CPU architectures to outperform equivalent scalar computations in performance. The vector API offers a way to build sophisticated vector algorithms in Java while utilizing the HotSpot VM's pre-existing support for vectorization and a user model that makes vectorization more reliable and predictable. By supporting a wide range of CPU architectures, delivering consistent runtime compilation and performance on the x64 and AArch64 architectures, and offering a concise and simple API to describe a variety of vector operations, the proposal intends to be platform-agnostic. Another goal is "graceful degradation," in which a vector computation would deteriorate gracefully and continue to run if it could not be fully expressed at runtime as a series of hardware vector instructions, either because one CPU architecture does not support another or because some instructions are not supported by that architecture.

Porting JDK to windows/AArch64 and Alpine Linux:

Extending the JDK platform to Windows/AArch64. Windows/AArch64 has grown in importance due to demand as a new server-class, and consumer AArch64 (ARM64) hardware has been released. Although the actual porting is already mostly finished, the inclusion of the port into the mainline JDK repository is the major objective of this request.

Alpine Linux and other Linux distributions that use musl as their primary C library support the JDK's port to those architectures. Musl implements the standard library functionality made available by the ISO C and Posix standards in Linux. Alpine Linux is often used in cloud deployments, microservices, and container settings because of its small image size. A Linux Docker image is less than 6MB in size. Tomcat, Jetty, Spring, and other well-known frameworks will operate in these systems natively if Java is allowed to run out of the box in such circumstances. A user can construct an even smaller image designed to execute a particular application by using jlink to shrink the Java runtime.

Records Classes:

Offering record types that serve as transparent containers for immutable data Nominal tuples can be regarded as records. JDK 14 and JDK 15 provided previews of one of the most eagerly awaited innovations in the release: lowering the ceremonial of Java by eliminating boilerplate code. The plan aims to create an object-oriented construct that expresses a straightforward aggregation of values, assists developers in modelling immutable data as opposed to extensible behaviour, automatically implements data-driven methods like equals and accessors and maintains enduring Java principles like nominal typing and migration compatibility.

Socket Channels:

Unix-domain socket channels have been added, enabling support for AF UNIX sockets in the socket channel and server socket channel APIs of the nio. channels package. The plan also extends the inherited channel system to accommodate server socket channels and sockets in the Unix domain. On the same host, interprocess communication takes place across Unix-domain sockets. In most ways, they are comparable to TCP/IP sockets, with the exception that filesystem path names are used to address them rather than IP addresses and port numbers. The new functionality aims to support all Unix-domain socket channel features that are shared by Windows and the main Unix platforms. In terms of reading/write behaviour, connection formation, accepting incoming connections from servers, and multiplexing with other non-blocking selectable channels in a selector, Unix-domain socket channels will operate similarly to current TCP/IP channels. TCP/IP loopback connections are less dependable and less effective for local, inter-process communication than Unix-domain sockets.

Foreign memory access API:

 Java programs can securely access foreign memory outside of the Java heap. JDK 16 would re-incubate the foreign-memory access API with improved functionality after it had previously been incubated in JDK 14 and JDK 15. Now that their different roles in the system are clearly defined, the Memory Segment and Memory Addresses interfaces. This proposal aims to provide a single API that can be used to access native, persistent, and managed heap memory, among other types of foreign memory. The security of the JVM shouldn't be jeopardized by the API. The idea is motivated by the fact that many Java programmes access external memory, including Ignite, Memcached, and MapDB. But there isn't a good way to access foreign memory using the Java API.

Pattern Matching:

Pattern matching for the instanceof operator, which was previewed in JDK 14 and JDK 15. JDK 16 would contain the final version. In particular, the conditional extraction of components from objects can be represented more concisely and safely in a programme thanks to pattern matching.

package tool:

Jpackage, which was first introduced as an incubator tool in JDK 14, remains an incubator in JDK 15. In order to provide users with a natural installation experience and to enable the specification of launch-time settings at the time of packaging, JDK 16 sees the introduction of jpackage, which now supports native package formats. On Windows, these formats include MSI and exe. On macOS, pkg and dmg, and on Linux, deb and rpm. The utility can be used programmatically or straight from the command line. Instead of being added to the classpath or module path, many Java programmes need to be installed on native systems in a first-class manner. This is a problem that the new packaging tool attempts to solve. For the native platform, an installable package is required.

Migration to GitHub:

Migration from Mercurial to Git to GitHub, with JDK 16 source code repositories moving to the well-known code-sharing platform. This plan would include JDK feature releases and JDK update releases for Java 11 and later. The Mercurial JDK and JDK-sandbox moved to Git, GitHub, and Skara on September 5 and are now accepting contributions.

Java version 16 API specification: