JDK 21 Download: How to Install and Use the Latest Java Development Kit
Java is one of the most popular and widely used programming languages in the world. It powers millions of applications across various domains, such as web, mobile, desktop, cloud, embedded, and enterprise. Java is also a platform-independent language, which means that it can run on any system that supports a Java Virtual Machine (JVM).
However, to develop and run Java applications, you need a software package called Java Development Kit (JDK). JDK contains all the tools and libraries that you need to compile, debug, test, and execute Java code. JDK also includes a Java Runtime Environment (JRE), which is a subset of JDK that contains only the components that are required to run Java applications.
jdk 21 download
The latest version of JDK is JDK 21, which is scheduled to be released in September 2023. JDK 21 is the next long-term support (LTS) release of Oracle's standard Java implementation, which means that it will receive updates and security patches for several years. JDK 21 is also the reference implementation of version 21 of the Java SE Platform, as specified by JSR 396 in the Java Community Process.
JDK 21 introduces many new features and enhancements that aim to improve the performance, security, productivity, and compatibility of Java. Some of the highlights of JDK 21 are:
String Templates (Preview): A new syntax for creating formatted strings using placeholders and expressions.
Sequenced Collections: A new interface for collections that maintain a stable iteration order.
Generational ZGC: A new garbage collection algorithm that divides the heap into generations and collects them separately.
Record Patterns: A new way to deconstruct records into their components using pattern matching.
Pattern Matching for switch: A new feature that allows switch expressions and statements to use patterns instead of constants.
Foreign Function & Memory API (Third Preview): A new API that allows Java programs to access native libraries and memory without using JNI.
Unnamed Patterns and Variables (Preview): A new feature that allows patterns and variables to be unnamed when they are not needed.
Virtual Threads: A new concurrency model that allows creating lightweight threads that are managed by the JVM.
Unnamed Classes and Instance Main Methods (Preview): A new feature that allows creating anonymous classes with instance methods.
Scoped Values (Preview): A new feature that allows creating values that are scoped to a thread or a fiber.
Vector API (Sixth Incubator): A new API that allows performing vector operations on arrays of primitive types.
Deprecate the Windows 32-bit x86 Port for Removal: A proposal to deprecate and remove the support for Windows 32-bit x86 platform in future releases.
Prepare to Dis Continue the article:
pose the Applet API for Removal: A proposal to deprecate and remove the Applet API and related classes in future releases.
Enhanced Pseudo-Random Number Generators: A new feature that allows creating and using custom random number generators.
In this article, we will show you how to download and install JDK 21 on different platforms, and how to use some of the new features and enhancements of JDK 21. We will also provide some tips and best practices for using JDK 21 effectively and securely.
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how to install jdk 21 on windows
how to install jdk 21 on linux
how to install jdk 21 on mac
how to update to jdk 21 from previous versions
how to uninstall jdk 21 from windows, linux, or mac
how to configure java_home and path for jdk 21 on windows, linux, or mac
how to check java version and verify jdk 21 installation on windows, linux, or mac
how to compile and run java programs using jdk 21 on windows, linux, or mac
how to use javac, java, jar, and javadoc commands in jdk 21 on windows, linux, or mac
how to use new features and enhancements in java se platform version 21
how to migrate existing java applications to use jdk 21
how to troubleshoot common issues and errors in jdk 21 installation and usage
how to report bugs and provide feedback for jdk 21
how to access documentation and release notes for jdk 21
how to learn more about the development and release process of jdk 21
How to Download JDK 21
There are two main sources from where you can download JDK 21: the official website of Oracle Java Downloads, and the early-access builds of OpenJDK JDK 21.
The official website of Oracle Java Downloads
The official website of Oracle Java Downloads is the primary source for downloading the latest stable releases of JDK. You can find the download links for JDK 21 for Linux, macOS, and Windows platforms on this page:
To download JDK 21 from this website, you need to accept the Oracle Technology Network License Agreement for Oracle Java SE, which is a commercial license that requires you to pay a fee if you use JDK 21 for production purposes. You also need to create an Oracle account or sign in with an existing one.
The early-access builds of OpenJDK JDK 21
The early-access builds of OpenJDK JDK 21 are the pre-release versions of JDK 21 that are available for testing and evaluation purposes. You can find the download links for JDK 21 for Linux, macOS, and Windows platforms on this page:
To download JDK 21 from this website, you do not need to accept any license agreement or create any account. However, you should be aware that these builds are not fully tested and may contain bugs or errors. You should not use them for production purposes or rely on them for critical applications.
The compatibility and licensing issues of JDK 21
Before you download and install JDK 21, you should consider the compatibility and licensing issues that may arise from using it. For example:
Compatibility with previous versions of Java: JDK 21 may not be compatible with some of the features or libraries that were available in previous versions of Java. For instance, some of the deprecated or removed APIs in JDK 21 may break your existing code or cause runtime errors. You should check the compatibility guide for JDK 21 to see what changes have been made and how to migrate your code accordingly:
Licensing with Oracle Java SE: As mentioned earlier, if you download JDK 21 from the official website of Oracle Java Downloads, you need to accept the Oracle Technology Network License Agreement for Oracle Java SE, which is a commercial license that requires you to pay a fee if you use JDK 21 for production purposes. You should read the terms and conditions of this license carefully before downloading and installing JDK 21:
Licensing with OpenJDK: If you download JDK 21 from the early-access builds of OpenJDK JDK 21, you do not need to accept any license agreement. However, you should be aware that OpenJDK is licensed under the GNU General Public License version 2 with a linking exception (GPLv2+CE), which is an open-source license that allows you to use, modify, and distribute JDK 21 freely. You should read the terms and conditions of this license before downloading and installing JDK 21:
Continue the article:
How to Install JDK 21
Once you have downloaded JDK 21 from your preferred source, you can proceed to install it on your system. The installation process may vary depending on the platform and the type of package that you have downloaded. Here are the general steps for installing JDK 21 on Linux, macOS, and Windows platforms:
The installation instructions for Linux
If you have downloaded JDK 21 as a compressed archive file (.tar.gz), you can follow these steps to install it on Linux:
Extract the archive file to a location of your choice, such as /usr/local/jdk-21.
Add the bin directory of the extracted JDK 21 to your PATH environment variable, such as export PATH=/usr/local/jdk-21/bin:$PATH.
Optionally, set the JAVA_HOME environment variable to point to the extracted JDK 21 directory, such as export JAVA_HOME=/usr/local/jdk-21.
If you have downloaded JDK 21 as a package file (.rpm or .deb), you can follow these steps to install it on Linux:
Use the appropriate package manager command to install the package file, such as sudo rpm -ivh jdk-21_linux-x64_bin.rpm or sudo dpkg -i jdk-21_linux-x64_bin.deb.
The package manager will automatically create a symbolic link to the installed JDK 21 directory in /usr/java/latest, and add it to your PATH and JAVA_HOME environment variables.
The installation instructions for macOS
If you have downloaded JDK 21 as a compressed archive file (.tar.gz), you can follow these steps to install it on macOS:
Extract the archive file to a location of your choice, such as /Library/Java/JavaVirtualMachines/jdk-21.jdk.
Add the bin directory of the extracted JDK 21 to your PATH environment variable, such as export PATH=/Library/Java/JavaVirtualMachines/jdk-21.jdk/Contents/Home/bin:$PATH.
Optionally, set the JAVA_HOME environment variable to point to the extracted JDK 21 directory, such as export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-21.jdk/Contents/Home.
If you have downloaded JDK 21 as a disk image file (.dmg), you can follow these steps to install it on macOS:
Double-click the disk image file to mount it.
Double-click the installer icon to launch the installer application.
Follow the instructions on the installer screens to complete the installation.
The installer will automatically create a symbolic link to the installed JDK 21 directory in /Library/Java/JavaVirtualMachines/jdk-21.jdk, and add it to your PATH and JAVA_HOME environment variables.
Continue the article:
The installation instructions for Windows
If you have downloaded JDK 21 as a compressed archive file (.zip), you can follow these steps to install it on Windows:
Extract the archive file to a location of your choice, such as C:\Program Files\Java\jdk-21.
Add the bin directory of the extracted JDK 21 to your PATH environment variable, such as set PATH=C:\Program Files\Java\jdk-21\bin;%PATH%.
Optionally, set the JAVA_HOME environment variable to point to the extracted JDK 21 directory, such as set JAVA_HOME=C:\Program Files\Java\jdk-21.
If you have downloaded JDK 21 as an executable installer file (.exe), you can follow these steps to install it on Windows:
Double-click the installer file to launch the installer application.
Follow the instructions on the installer screens to complete the installation.
The installer will automatically create a registry entry for the installed JDK 21 directory in HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\JDK\21, and add it to your PATH and JAVA_HOME environment variables.
How to Verify the Installation of JDK 21
After you have installed JDK 21 on your system, you can verify that it is working properly by using some simple commands. Here are the steps to verify the installation of JDK 21 on different platforms:
The verification steps for Linux and macOS
Open a terminal window and type the following commands:
java -version: This command will display the version of Java that is currently running on your system. You should see something like this:
java version "21" 2023-09-14 LTS Java(TM) SE Runtime Environment (build 21+12-LTS-237) Java HotSpot(TM) 64-Bit Server VM (build 21+12-LTS-237, mixed mode, sharing)
javac -version: This command will display the version of Java compiler that is currently available on your system. You should see something like this:
javac 21
java --list-modules: This command will display the list of modules that are included in JDK 21. You should see something like this:
java.base@21 java.compiler@21 java.datatransfer@21 java.desktop@21 java.instrument@21 java.logging@21 java.management@21 java.management.rmi@21 java.naming@21 java.net.http@21 java.prefs@21 java.rmi@21 java.scripting@21 java.se@21 java.security.jgss@21 java.security.sasl@21 java.smartcardio@21 java.sql@21 java.sql.rowset@21 java.transaction.xa@21 java.xml@21 java.xml.crypto@21 jdk.accessibility@21 jdk.aot@21 jdk.attach@21 jdk.charsets@21 jdk.compiler@21 jdk.crypto.cryptoki@21 jdk.crypto.ec@21 jdk.crypto.mscapi@21 jdk.dynalink@21 jdk.editpad@21 jdk.hotspot.agent@21 jdk.httpserver@21 jdk.incubator.foreign@0.1-incubating-SNAPSHOT.1.0.0+0-2023-06-15-062438.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1 (incubating) jdk.incubator.vector@0.2-incubating-SNAPSHOT.2.0.0+0-2023-06-15-062438.b5d8e8d Continue the article:
b5d8e8d (incubating) jdk.jartool@21 jdk.javadoc@21 jdk.jcmd@21 jdk.jconsole@21 jdk.jdeps@21 jdk.jdi@21 jdk.jdwp.agent@21 jdk.jfr@21 jdk.jlink@21 jdk.jpackage@21 jdk.jshell@21 jdk.jsobject@21 jdk.jstatd@21 jdk.localedata@21 jdk.management.agent@21 jdk.management.jfr@21 jdk.naming.dns@21 jdk.naming.rmi@21 jdk.net@21 jdk.nio.mapmode@21 jdk.sctp@21 jdk.security.auth@21 jdk.security.jgss@21 jdk.unsupported@21 jdk.unsupported.desktop@21 jdk.xml.dom@21 jdk.zipfs@21
If the commands display the expected output, then JDK 21 is installed correctly on your system.
The verification steps for Windows
Open a command prompt window and type the following commands:
java -version: This command will display the version of Java that is currently running on your system. You should see something like this:
java version "21" 2023-09-14 LTS Java(TM) SE Runtime Environment (build 21+12-LTS-237) Java HotSpot(TM) 64-Bit Server VM (build 21+12-LTS-237, mixed mode, sharing)
javac -version: This command will display the version of Java compiler that is currently available on your system. You should see something like this:
javac 21
java --list-modules: This command will display the list of modules that are included in JDK 21. You should see something like this:
java.base@21 java.compiler@21 java.datatransfer@21 java.desktop@21 java.instrument@21 java.logging@21 java.management@21 java.management.rmi@21 java.naming@21 java.net.http@21 java.prefs@21 java.rmi@21 java.scripting@21 java.se@21 java.security.jgss@21 java.security.sasl@21 java.smartcardio@21 java.sql@21 java.sql.rowset@21 java.transaction.xa@21 java.xml@21 java.xml.crypto@21 jdk.accessibility@21 Continue the article:
jdk.aot@21 jdk.attach@21 jdk.charsets@21 jdk.compiler@21 jdk.crypto.cryptoki@21 jdk.crypto.ec@21 jdk.crypto.mscapi@21 jdk.dynalink@21 jdk.editpad@21 jdk.hotspot.agent@21 jdk.httpserver@21 jdk.incubator.foreign@0.1-incubating-SNAPSHOT.1.0.0+0-2023-06-15-062438.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1a9f7c4b7a6a.1 (incubating) jdk.incubator.vector@0.2-incubating-SNAPSHOT.2.0.0+0-2023-06-15-062438.b5d8e8d b5d8e8d (incubating) jdk.jartool@21 jdk.javadoc@21 jdk.jcmd@21 jdk.jconsole@21 jdk.jdeps@21 jdk.jdi@21 jdk.jdwp.agent@21 jdk.jfr@21 jdk.jlink@21 jdk.jpackage@21 jdk.jshell@21 jdk.jsobject@21 jdk.jstatd@21 jdk.localedata@21 jdk.management.agent@21 jdk.management.jfr@21 jdk.naming.dns@21 jdk.naming.rmi@21 jdk.net@21 jdk.nio.mapmode@21 jdk.sctp@21 jdk.security.auth@21 jdk.security.jgss@21 jdk.unsupported@21 jdk.unsupported.desktop@21 jdk.xml.dom@21 jdk.zipfs@21
If the commands display the expected output, then JDK 21 is installed correctly on your system.
How to Use JDK 21
After you have verified the installation of JDK 21 on your system, you can start using it to develop and run Java applications. Here are some of the basic commands and tools that you can use with JDK 21:
The basic commands and tools of JDK 21
JDK 21 provides several commands and tools that you can use to perform various tasks related to Java development and execution. Some of the most common ones are:
java: This command is used to launch a Java application from a class file or a JAR file.
javac: This command is used to compile Java source files into class files.
jar: This command is used to create and manipulate JAR files, which are compressed archives of class files and other resources.
javadoc: This command is used to generate HTML documentation from Java source files.
jshell: This command is used to launch an interactive shell that allows you to evaluate Java expressions and statements without compiling them.
jlink: This command is used to create custom runtime images that contain only the modules that are required by your application.
jpackage: This command is used to create native installers and launchers for your Java application.
jmap: This command is used to print memory-related information for a Java process or a core file.
jstack: This command is used to print stack traces for a Java process or a core file.
jstat: This command is used to monitor the performance and resource consumption of a Java process.
jfr: This command is used to record and analyze Java Flight Recorder events, which are high-level data about the behavior and performance of a Java application.
jcmd: This command is used to send diagnostic commands to a Java process.
jconsole: This command is used to launch a graphical console that allows you to monitor and manage a Java process.
jvisualvm: This command is used to launch a graphical tool that allows you to monitor and Continue the article:
analyze a Java process.
You can find more information and examples on how to use these commands and tools in the JDK 21 documentation:
The new features and syntax of JDK 21 with examples
JDK 21 introduces many new features and enhancements that make Java more expressive, concise, and efficient. Here are some of the most notable ones with examples:
String Templates (Preview)
String templates are a new syntax for creating formatted strings using placeholders and expressions. They are similar to string interpolation in other languages, such as Python or Ruby. String templates use the dollar sign ($) as a prefix for placeholders, which can be either simple names or complex expressions enclosed in curly braces. For example:
// A simple string template with a name placeholder String name = "Alice"; String greeting = $"Hello, $name!"; System.out.println(greeting); // prints "Hello, Alice!" // A complex string template with an expression placeholder int x = 10; int y = 20; String result = $"The sum of $x and $y is $x + y"; System.out.println(result); // prints "The sum of 10 and 20 is 30"
String templates are a preview feature in JDK 21, which means that they are not enabled by default and may change or be removed in future releases. To use string templates, you need to pass the --enable-preview flag to both the javac and java commands, and specify the source and target versions as 21. For example:
javac --enable-preview --source 21 --target 21 StringTemplateExample.java java --enable-preview StringTemplateExample
Sequenced Collections
Sequenced collections are a new interface for collections that maintain a stable iteration order. They are similar to ordered collections in other languages, such as C# or Swift. Sequenced collections extend the Collection interface and add two default methods: first() and last(), which return the first and last elements of the collection, respectively. For example:
// A sequenced collection of strings SequencedCollection names = List.of("Alice", "Bob", "Charlie"); System.out.println(names.first()); // prints "Alice" System.out.println(names.last()); // prints "Charlie" // A sequenced collection of integers SequencedCollection numbers = Set.of(1, 2, 3); System.out.println(numbers.first()); // prints "1" System.out.println(numbers.last()); // prints "3"
Sequenced collections are useful for algorithms that rely on the order of elements in a collection, such as sorting, searching, or filtering. They also provide a consistent and intuitive way to access the first and last elements of a collection, without having to use indexes or iterators. Continue the article:
Generational ZGC
Generational ZGC is a new garbage collection algorithm that divides the heap into generations and collects them separately. It is an extension of the Z Garbage Collector (ZGC), which was introduced in JDK 11 as an experimental feature. ZGC is a low-latency garbage collector that uses colored pointers and load barriers to achieve concurrent and pauseless garbage collection. Generational ZGC adds a young generation to ZGC, which allows it to collect short-lived objects more efficiently and reduce the memory footprint of the heap. For example:
// A simple program that creates and discards many short-lived objects public class GenerationalZGCExample public static void main(String[] args) for (int i = 0; i
To run this program with Generational ZGC, you need to pass the -XX:+UseZGC and -XX:+UseGenerationalZGC flags to the java command, and optionally specify the size of the young generation with the -XX:YoungGenerationSize flag. For example:
java -XX:+UseZGC -XX:+UseGenerationalZGC -XX:YoungGenerationSize=1G GenerationalZGCExample
Generational ZGC is an experimental feature in JDK 21, which means that it is not enabled by default and may change or be removed in future releases. To use Generational ZGC, you need to pass the --enable-experimental-vm-options flag to the java command.
Record Patterns
Record patterns are a new way to deconstruct records into their components using pattern matching. They are similar to tuple patterns or positional patterns in other languages, such as C# or Scala. Record patterns use the record name and a list of variables or patterns to match against the components of a record. For example:
// A record that represents a point in a 2D space record Point(int x, int y) // A record pattern that matches a point with x = 0 Point(0, var y) p = new Point(0, 10); System.out.println(p); // prints "Point[x=0, y=10]" // A record pattern that matches a point with y = x + 1 Point(var x, x + 1) q = new Point(9, 10); System.out.println(q); // prints "Point[x=9, y=10]"
Record patterns are a preview feature in JDK 21, which means that they are not enabled by default and may change or be removed in future releases. To use record patterns, you need to pass the --enable-preview flag to both the javac and java commands, and specify the source and target versions as 21. For example:
javac --enable-preview --source 21 --target 21 RecordPatternExample.java java --enable-preview RecordPatternExample Continue the article:
Pattern Matching for switch
Pattern matching for switch is a new feature that allows switch expressions and statements to use patterns instead of constants. Patterns are more expressive and flexible than constants, as they can match against different types, values, and structures of the input. Pattern matching for switch also eliminates the need for explicit casting, instanceof checks, and null checks. For example:
// A switch expression that uses patterns to match against different shapes sealed interface Shape permits Circle, Rectangle, Triangle record Circle(double radius) implements Shape record Rectangle(double length, double width) implements Shape record Triangle(double base, double height) implements Shape Shape shape = new Circle(10); double area = switch (shape) case Circle(var r) -> Math.PI * r * r; case Rectangle(var l, var w) -> l * w; case Triangle(var b, var h) -> b * h / 2; ; System.out.println(area); // prints "314.1592653589793"
Pattern matching for switch is a preview feature in JDK 21, which means that they are not enabled by default and may change or be removed in future releases. To use pattern matching for switch, you need to pass the --enable-preview flag to both the javac and java commands, and specify the source and target versions as 21. For example:
javac --enable-preview --source 21 --target 21 PatternMatchingForSwitchExample.java java --enable-preview PatternMatchingForSwitchExample
How to Benefit from JDK 21
JDK 21 offers many benefits for Java developers and users, such as improved performance, security, productivity, and compatibility. Here are some of the ways that you can benefit from JDK 21:
The performance and security benefits of JDK 21
JDK 21 improves the performance and security of Java applications by providing new features and enhancements that optimize the execution, memory management, and encryption of Java code. Some of the performance and security benefits of JDK 21 are:
Faster startup and lower memory footprint with Generational ZGC: Generational ZGC reduces the startup time and memory usage of Java applications by collecting short-lived objects more efficiently and compacting the heap more effectively.
Better vectorization and parallelization with Vector API: Vector API enables Java applications to perform vector operations on arrays of primitive types, which can improve the performance of computation-intensive tasks such as machine learning, image processing, and cryptography.
More scalable and responsive concurrency with Virtual Threads: Virtual Threads allow Java applications to create lightweight threads that are managed by the JVM, which can improve the scalability and responsiveness of concurrent tasks such as network I/O, database access, and web services.
Stronger encryption and authentication with TLS 1.3: JDK 21 supports Transport Layer Security (TLS) version 1.3, which is the latest and most secure version of the protocol that provides encryption and authentication for network communication.
The productivity and compatibility benefits of JDK 21
JDK 21 improves the productivity and compatibility of Java developers by providing new features and enhancements that simplify the syntax, reduce the boilerplate code, and increase the expressiveness of Java code. Some of the productivity and compatibility benefits of JDK 21 are:
Easier string formatting with String Templates: String Templates allow Java developers to create formatted strings using placeholders and expressions, which can reduce the verbosity and complexity of string concatenation and formatting.
More consistent iteration order with Sequenced Collections: Sequenced Collections allow Java developers to use collections that maintain a stable iteration order, which can make the algorithms that rely on the order of elements in a collection more predictable and reliable.
More concise deconstruction with Record Patterns: Record Patterns allow Java developers to deconstruct records into their components using pattern matching, which can eliminate the need for getters, setters, constructors, equals, hashCode, toString, and other boilerplate code.
More expressive switching with Pattern Matching for switch: Pattern Matching for switch allows Java developers to use patterns instead of constants in switch expressions and statements, which can make the switching logic more expressive and flexible.
Conclusion
In this article, we have shown you how to download and install JDK 21 on different platforms, how to verify the installation of JDK 21 on your system, how to use some of the basic commands and tools of JDK 21, how to use some of the new features [user]( and enhancements of JDK 21, and how to benefit from JDK 21 in terms of performance, security, productivity, and compatibility. We hope that this article has helped you to get started with JDK 21 and to explore its new features and improvements. We also encourage you to try out JDK 21 for yourself and to share your feedback and suggestions with the Java community.
FAQs
Here are some of the frequently asked questions about JDK 21 and their answers:
What is the difference between JDK and JRE?
JDK stands for Java Development Kit, which is a software package that contains all the tools and libraries that you need to develop and run Java applications. JRE stands for Java Runtime Environment, which is a subset of JDK that contains only the components that are required to run Java applications. You need JDK if you want to create or compile Java applications, and you need JRE if you want to execute or run Java applications.
What is the difference between JDK and OpenJDK?
JDK is the standard Java implementation from Oracle, which is a commercial product that requires a license fee for production use. OpenJDK is an open-source Java implementation from the OpenJDK community, which is a free product that does not require a license fee for any use. Both JDK and OpenJDK are based on the same Java SE Platform specification, but they may have some differences in terms of features, performance, security, and compatibility.
How can I update my existing Java applications to JDK 21?
To update your existing Java applications to JDK 21, you need to recompile them with the javac command using the source and target versions as 21. You also need to test your applications with JDK 21 to ensure that they are compatible with the new features and enhancements of JDK 21. You may need to modify your code or use migration tools if your applications use any deprecated or removed APIs in JDK 21.
How can I switch between different versions of JDK on my system?
To switch between different versions of JDK on your system, you need to change the PATH and JAVA_HOME environment variables to point to the desired JDK directory. You can also use tools such as SDKMAN or jEnv to manage multiple versions of JDK on your system.
How can I report bugs or provide feedback on JDK 21?
To report bugs or provide feedback on JDK 21, you can use the following channels:
The Java Bug System: This is the official platform for reporting bugs or requesting enhancements for JDK 21. You can find the bug database and the submission guidelines here:
The OpenJDK Mailing Lists: These are the official forums for discussing technical issues and proposals related to JDK 21. You can find the mailing lists and the subscription instructions here:
The OpenJDK Project Feedback Page: This is the official page for providing general feedback or suggestions for JDK 21. You can find the feedback form and the privacy policy here:
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