Oracle has released version 27 of the Java programming language and virtual machine. As the second non-LTS release since JDK 25, the final feature set includes nine JEPs, five of which are still…

SquirrelJME is a Java ME 8 Virtual Machine for embedded and Internet of Things devices. It has the ultimate goal of being 99.9% compatible with the Java ME standard. It consists of a class library, na...

Compile Rust to Java bytecode and runnable JARs. Contribute to IntegralPilot/rustc_codegen_jvm development by creating an account on GitHub.

Low-level interface to Java VM very much like .C/.Call and friends. Allows creation of objects, calling methods and accessing fields.

AWS Identity and Access Management (IAM) Roles Anywhere now provides a plugin for the AWS SDK for Java v2 that enables workloads running outside of AWS to obtain temporary AWS credentials directly within the Java application process. The plugin runs in the same Java Virtual Machine (JVM) as your application, removing the need to run the IAM Roles Anywhere credential helper as a separate process or configure credential_process in your AWS profile. You configure the plugin on your AWS SDK for Java v2 service client builder to automatically resolve temporary credentials without writing credential-fetching logic. The plugin handles calling CreateSession and automatically refreshing credentials before they expire. It supports RSA, Elliptic Curve (EC), and ML-DSA key types and requires Java 8 or higher. There is no additional charge for using the plugin. IAM Roles Anywhere is available in all AWS Regions, including the AWS GovCloud (US) Regions, AWS European Sovereign Cloud (Germany) Region, and China Regions. To get started with the Java plugin, see the IAM Roles Anywhere Java plugin documentation. For the current version, release notes, and signature verification instructions, see the plugin's page on the Maven Central website and the roles-anywhere-java repository on GitHub.

AWS Identity and Access Management (IAM) Roles Anywhere now provides a plugin for the AWS SDK for Java v2 that enables workloads running outside of AWS to obtain temporary AWS credentials directly within the Java application process. The plugin runs in the same Java Virtual Machine (JVM) as your application, removing the need to run the IAM Roles Anywhere credential helper as a separate process or configure credential_process in your AWS profile. You configure the plugin on your AWS SDK for Java v2 service client builder to automatically resolve temporary credentials without writing credential-fetching logic. The plugin handles calling CreateSession and automatically refreshing credentials before they expire. It supports RSA, Elliptic Curve (EC), and ML-DSA key types and requires Java 8 or higher. There is no additional charge for using the plugin. IAM Roles Anywhere is available in all AWS Regions, including the AWS GovCloud (US) Regions, AWS European Sovereign Cloud (Germany) Region, and China Regions. To get started with the Java plugin, see the IAM Roles Anywhere Java plugin documentation. For the current version, release notes, and signature verification instructions, see the plugin's page on the Maven Central website and the roles-anywhere-java repository on GitHub.

https://aws.amazon.com/iam/roles-anywhere/ now provides a plugin for the https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/home.html that enables workloads running outside of AWS to obtain temporary AWS credentials directly within the Java application process. The plugin runs in the same Java Virtual Machine (JVM) as your application, removing the need to run the IAM Roles Anywhere credential helper as a separate process or configure credential_process in your AWS profile. You configure the plugin on your AWS SDK for Java v2 service client builder to automatically resolve temporary credentials without writing credential-fetching logic. The plugin handles calling CreateSession and automatically refreshing credentials before they expire. It supports RSA, Elliptic Curve (EC), and ML-DSA key types and requires Java 8 or higher. There is no additional charge for using the plugin. IAM Roles Anywhere is available in all https://docs.aws.amazon.com/general/latest/gr/rolesanywhere.html, including the AWS GovCloud (US) Regions, AWS European Sovereign Cloud (Germany) Region, and China Regions. To get started with the Java plugin, see the https://docs.aws.amazon.com/rolesanywhere/latest/userguide/java-plugin.html. For the current version, release notes, and signature verification instructions, see the https://central.sonatype.com/artifact/software.amazon.rolesanywhere.plugin/roles-anywhere-java on the Maven Central website and the https://github.com/aws-sdk-plugin/roles-anywhere-java on GitHub.

I’ve Read 10+ JVM and Java Performacne Books: Here Are My Top 6 Recommendations for Senior Java developers My favorite books to learn JVM internals, GC and Java Performance Tuning Hello friends, In the last couple of years, I have seen a trend of many Java developers wanted to learn more and more about JVM internals and how Java Virtual Machine and its different component works. This trend was not so strong in the last decade, but with more and more focus on concurrency, performance, and scalability, Java developer is exploring JVM internals, Garbage collection, and Performance tuning in more detail. Unfortunately, there are not many good books to learn about JVM internals and their different components, but fortunately, we have an excellent Java Virtual Machine specification to learn fundamentals. It is also the most up-to-date reference because Java and JVM are kept changing, especially after each Java version upgrade. Once you know the fundamentals, you can easily apply the more advanced concepts. I receive a lot of emails about the recommendation of the best books to learn JVM internals and garbage collections from experienced Java programmers, and hence I decided to write about this post to share some of the best books on JVM internals and Java performance, Garbage collection, and memory management in general. Over the years, I have read many books on Java performance and JVM tuning and I sharing the best of the very best books for senior developers. The books in this list are solely for advanced Java developer who has at least 4 to 6 years of Java working experience under their belt. It’s not for beginners, and most likely lot of concepts will go top of your head unless you understand critical components like JIT, Garbage collector, Java heap structure, byte codes, and other JVM internals. And, if you prefer online courses, which I do nowadays, I also suggest you check the Java Application Performance and Memory Management course on Udemy, which covers memory management, Java heap architecture, garbage collection and JVM concepts. Java Application Performance Tuning and Memory Management 6 Best JVM Internals and Java Performance Books for Experienced Developers Without wasting any more of your time, here is my list of some of the best books to learn JVM internals, Garbage Collection, and Performance tuning in Java. Though you don’t need to read all the books to become an expert in JVM internals, you choose the one book along with the specification and stick with it. Once you have good knowledge, you can check other books to learn more about them. 1. Optimizing Java by Benjamin J Evans The Optimizing Java: Practical Techniques for Improving JVM Application Performance 1st Edition by Benjamin J Evans, James Gough, and Chris Newland is one of the best books to understand how Garbage collection and JVM works internally. I originally missed this book on the list because I haven’t read it until Ben suggested it in the comments, but just reading a couple of pages, I was convinced that this book deserves mention in this list. Many books focus mainly on G.C., but this one describes many more aspects of JVM internals like threading, JVM internal memory representation, bytecode, JIT compilers, etc. Moreover, the book contains an overview of many useful tools that can help you on a daily basis work with JVM. This book is also much more approachable in this list than some specialized books like The Garbage collection handbook, which is excellent for people who want to learn G.C. algorithms in-depth but may not be needed for most of the developers. If you need some help and want to see things, in reality, I also suggest you check out the Java Application Performance and Memory Management course by Matt Greecroft and Virtual Programmers. It’s a wonderful course to learn how to analyze heap dump, improve Java performance, understand GC logs, and solve memory leaks. I highly recommend it. 2. The Java Virtual Machine Specification, Java S.E. 25 Edition This is the most authoritative source to learn about a new Java virtual machine that comes as part of the JDK 25 release. So it includes lambda expression, method reference, static factory method, string in switch case, and other language enhancements made in the Java S.E. 25 release and previous releases. When I first tried to read this specification, I was overwhelmed with the depth of the knowledge and wording, but slowly I picked it up. I don’t read it end-to-end but rather use it as reference material when I need to learn a particular topic. No doubt it’s an excellent reference and must-read guide for JVM internals by any Senior Java developers, and I accept the readability issue with the complexity of the subject matter unless we have proper JVM internal books aimed at average Java developers. However, if you want to learn more about JVM memory stuff, then the Java Memory Management course on Udemy is also an excellent resource. 3. Java Performance: In-Depth Advice for Tuning and Programming Java 8, 11, and Beyond by Scott Oaks This is the book I recommend to the average Java programmer to learn about JVM internals. It’s not as detailed and sophisticated as the above two books, but it contains enough detail on both Java Virtual Machine and Garbage collector, which I believe every experienced Java programmer should know. With a pragmatic approach, the author bridges the gap between coding and testing, asserting that anyone working with Java should possess a profound understanding of how code behaves in the Java Virtual Machine. The book, rated 4.6 out of 5 stars, presents practical insights into Java application performance using both the JVM and the Java platform. It delves into the nuances of various Java platforms and compilers, demystifies the workings of Java garbage collection, and introduces four essential principles for optimal performance testing. This book is the new edition of The Java Performance The Definitive Guide By Scott Oaks which I have included earlier on this list which is undoubtedly the best book to learn JVM internals for many Java programmers who are keen to learn the fundamentals of JVM and how different components of JVM works. In short, a must-read book for every experienced Java programmer. You can also combine this book with the Java Multithreading, Concurrency & Performance Optimization course by Michael Pogrebinsky to further learn Java performance optimization by actually watching and doing. 4. The Garbage Collection Handbook One of the exciting parts of the Java Virtual machine is automatic memory management, which is done by a Garbage collector. Garbage collection is a very complicated process and involves a sophisticated algorithm to collect unreachable objects without affecting the performance of the Java application negatively. The Garbage Collection Handbook: The Art of Automatic Memory Management (Chapman & Hall/CRC Applied Algorithms and Data Structures series) is one of the best books to understand Garbage collection algorithms in a systematic and practical way. If you are a senior Java developer with a focus on G.C. tuning and performance improvement, then this is the must-read book for you. 5. Java Performance by Charlie Hunt This is another book I used to recommend to my readers and students before I come across Java Performance The Definitive Guide By Scott Oaks, but it holds its ground even after that book claimed a lot of market share on the Java performance topic. Both Binu John and Charlie Hunt are the authority on JVM options and Java Performance space, and they teach essential JVM internals information in a much more readable way than you find in The Java Virtual Machine Specification, Java S.E. 8 Edition book. The only drawback is that it’s bit old and not up-to-date, but once you know the fundamentals, you can easily upgrade yourself with more recent concepts and development by reading these specifications and articles. 6. Java Performance Companion This is like the updated version of the previous book o learn about JVM internals and performance tuning. Again author Charlie Hunt teamed with Monica Beckwith, Poonam Parhar, and Bengt Rutisson to teach you how to improve the performance of Java applications. This is the most up-to-date book but only covers Java S.E. 8, which is not bad given most of the Java applications are still using Java S.E. 8. That’s all about some of the best books to learn Garbage Collection, Java Performance and JVM internals. These are great books to understand both theory and practical about how a Java virtual machine works, How garbage collector works, and how the Just in time compiler optimizes the performance of Java programs. As a senior Java developer it’s also expected from you to know Java inside out, and with an increased focus on JVM internals, G.C. tuning, and performance improvement, it would be imperative for an experienced Java developer to learn more and more about JVM and Garbage collector. Thanks you all for reading this article so far. If you like it then please share it helps a lot. --- I’ve Read 10+ JVM and Java Performacne Books: Here Are My Top 6 Recommendations for Senior Java… was originally published in Javarevisited on Medium, where people are continuing the conversation by highlighting and responding to this story.

Jazzer uses code coverage to steer generated inputs towards unexplored paths, crashes and vulnerabilities. The post Jazzer – coverage-guided, in-process fuzzer for the Java Virtual Machine appeared first on LinuxLinks.

In the last couple of years, I have seen a trend of many Java developers wants to learn more and more about JVM internals and how Java Virtual Machine and its different component works. This trend was not so strong in the last decade, but with more and more focus on concurrency, performance, and scalability, Java developer is exploring JVM internals, Garbage collection, and Performance tuning in more detail. Unfortunately, there are not many good books to learn about JVM internals and their different components, but fortunately, we have an excellent Java Virtual Machine specification to learn fundamentals. It is also the most up-to-date reference because Java and JVM are kept changing, especially after Java 10. --- Java Interview questions and tutorials

Debian 13 “Trixie” provides a clean, stable base for Java agent development. On a workstation, virtual machine, or cloud instance, you can compile Java projects, run local web servers, use the Google Agent Development Kit (ADK) Dev UI, and deploy an agent to Google Cloud Run. This guide builds a small ADK agent with time and weather tools. The complete project is available in the sample repository. ## 1. Prepare Debian Trixie Start with a Debian 13 installation and a user account that can run `sudo`. Confirm the operating-system version: . /etc/os-release printf '%s %s (%s)\n' "$NAME" "$VERSION_ID" "$VERSION_CODENAME" ## 2. Install the required tools Update the package index and install the base development tools: sudo apt-get update sudo apt-get install -y curl git maven unzip zip This project compiles with Java 25. One convenient way to install a matching JDK is SDKMAN!: curl -s "https://get.sdkman.io" | bash source "$HOME/.sdkman/bin/sdkman-init.sh" sdk list java Select an available Java 25 identifier from the list and install it (for example, `25-open`): sdk install java 25-open java --version mvn --version Both commands should report Java 25, and Maven must be version 3.6.3 or newer. The build enforces this minimum Maven version. ### Install the Google Cloud CLI Add Google's Debian package repository: sudo apt-get install -y apt-transport-https ca-certificates gnupg curl https://packages.cloud.google.com/apt/doc/apt-key.gpg \ | sudo gpg --dearmor -o /usr/share/keyrings/cloud.google.gpg echo "deb [signed-by=/usr/share/keyrings/cloud.google.gpg] https://packages.cloud.google.com/apt cloud-sdk main" \ | sudo tee /etc/apt/sources.list.d/google-cloud-sdk.list sudo apt-get update sudo apt-get install -y google-cloud-cli Verify the installation: gcloud version The Google Cloud CLI is required for Vertex AI authentication and Cloud Run deployment. It is not required if you only run the agent locally with a Gemini API key. ## 3. Clone and inspect the project git clone https://github.com/xbill9/adk-hello-world-java cd adk-hello-world-java The agent lives at `src/main/java/agents/multitool/MultiToolAgent.java`. Its public `ROOT_AGENT` field lets the ADK Dev UI discover it: public static final BaseAgent ROOT_AGENT = initAgent(); public static BaseAgent initAgent() { return LlmAgent.builder() .name("multi_tool_agent") .model("gemini-2.5-flash") .description("Agent to answer questions about the time and weather in a city.") .tools( FunctionTool.create(MultiToolAgent.class, "getCurrentTime"), FunctionTool.create(MultiToolAgent.class, "getWeather")) .build(); } The tools return structured maps with a `status` and a human-readable `report`. The time tool uses IANA time zones and includes aliases for cities such as San Francisco, Beijing, and Mumbai. ### Current ADK Java baseline This sample uses **ADK for Java 1.7.0** , the latest release available from Maven Central as of July 27, 2026. Both runtime dependencies use the same property so the core library and Dev UI cannot drift to different versions: <properties> <google-adk.version>1.7.0</google-adk.version> </properties> <dependency> <groupId>com.google.adk</groupId> <artifactId>google-adk</artifactId> <version>${google-adk.version}</version> </dependency> <dependency> <groupId>com.google.adk</groupId> <artifactId>google-adk-dev</artifactId> <version>${google-adk.version}</version> </dependency> Recent changes relevant to this project include: * **Java 25 build support.** ADK 1.6 updated its Spring AI integration and build so it works with Java 25. * **More reliable function-tool streaming.** ADK 1.6 aligned Gemini streaming function-call handling with the Python ADK, and 1.7 fixed reassembly of streamed function-call arguments. * **Cleaner command-line shutdown.** ADK now uses daemon threads for its shared HTTP client, preventing idle HTTP workers from keeping the JVM alive after the CLI exits. * **Safer loading and sessions.** Recent fixes restrict dynamic class loading and skill paths and prevent cross-user disclosure in `VertexAiSessionService`. * **More accurate observability.** ADK 1.7 includes tool-related tokens in `gen_ai.usage.input_tokens`. * **Gemini 3 flow compatibility.** ADK 1.7 can reorder forced function calls when a Gemini 3 model requires it. This sample remains on `gemini-2.5-flash` for a stable, broadly available tutorial baseline. These are framework improvements; the sample does not reimplement them. Keeping the ADK dependencies pinned to 1.7.0 is what brings them into the application. ## 4. Choose an authentication mode Run the setup script: ./init.sh It offers two modes: * **Gemini API key** for local development. Create a key in Google AI Studio. The script stores it in `~/gemini.key` with user-only permissions. * **Vertex AI** for local development and Cloud Run. Enter a Google Cloud project ID; the script then configures gcloud and Application Default Credentials (ADC). The selected mode is stored in `~/.adk-hello-world-java-auth`. Run `./init.sh` again whenever you want to switch modes. The launch scripts source `set_env.sh` automatically, so you do not need to export the variables by hand. For Vertex AI, your account and the Cloud Run service identity must have the required Vertex AI permissions. Cloud Run uses its service identity at runtime rather than a downloaded credential file. ## 5. Build, test, and lint Compile the project and run its eight JUnit Jupiter tests: make build make test The tests cover agent initialization, supported and unsupported cities, time-zone aliases, and null input. Run Checkstyle separately: make lint The lint target fails when Google Java Style warnings are found, which makes it useful in local development and continuous integration. ## 6. Run the command-line agent ./cli.sh Example session: You > What is the current time in Tokyo? Agent > The current time in Tokyo is 08:24. You > What is the weather in New York? Agent > The weather in New York is sunny with a temperature of 25 degrees Celsius (77 degrees Fahrenheit). You > quit ## 7. Use the ADK Dev UI Start the local server: ./devui.sh Open http://127.0.0.1:8080 in your browser. ADK scans the Maven output under `target/classes` and makes `multi_tool_agent` available in the UI. The `web.sh` script is retained as an alias for `devui.sh`. ADK 1.6 tightened WebSocket origin handling and warns when the Dev UI uses the `*` CORS default. That default is convenient for local development but should not be treated as an access-control mechanism for a public deployment. ## 8. Deploy to Cloud Run Cloud Run deployment uses Vertex AI rather than copying a local API key into the service. If you selected API-key mode, run `./init.sh` again and choose Vertex AI. Then deploy: ./cloudrun.sh The script runs one source deployment for the `adk-hello-world-java` service in `us-central1`. Because the repository contains a Dockerfile, Cloud Run builds that Dockerfile remotely; Docker does not need to be installed on the Debian system. The container reads Cloud Run's `PORT` environment variable and starts the ADK web server. When deployment completes, gcloud prints the service URL. The deployment is private by default because the service includes the ADK Dev UI and API. Configure authenticated callers with Cloud Run IAM. For a disposable public demonstration, replace `--no-allow-unauthenticated` with `--allow-unauthenticated` in `cloudrun.sh`; do not rely on CORS as access control. ## Project structure . ├── .dockerignore ├── .gcloudignore ├── Dockerfile ├── Makefile ├── cli.sh ├── cloudrun.sh ├── devui.sh ├── init.sh ├── pom.xml ├── set_env.sh └── src ├── main/java/agents/multitool/MultiToolAgent.java └── test/java/agents/multitool/MultiToolAgentTest.java ## Summary Debian Trixie provides everything needed to build and test a Java ADK agent locally. This sample keeps local authentication explicit, verifies the tool logic with JUnit, enforces Java style with Checkstyle, and uses Vertex AI service identity when deployed to Cloud Run. ## Resources * ADK Java quickstart * Google ADK for Java * ADK for Java 1.7.0 release notes * Deploy Cloud Run services from source * Configure Cloud Run service identity * SDKMAN! installation * Sample repository

SquirrelJME is a Java ME 8 Virtual Machine for embedded and Internet of Things devices. It has the ultimate goal of being 99.9% compatible with the Java ME standard. It consists of a class library, na...

A single cold start can push your Java Lambda function’s response time from milliseconds to seconds, enough to violate your p99 SLA, timeout a downstream service, and page your on-call. The Java Virtual Machine (JVM) performs best in long-running processes. Its Just-In-Time (JIT) compiler progressively optimizes code over thousands of invocations. Standard serverless execution environments [...]

Introduce strictly-initialized fields in the Java Virtual Machine. Such fields must be initialized before they are read, thus default values such as 0 or null are never observed. For strictly-initialized fields that are final, the same value is always observed. This is a preview VM feature, avail...

Smithereen can run on just about any OS that can run a modern Java virtual machine, but this page assumes Linux. Recommended minimum system requirements for a server are: 1 GB of RAM 2 CPU cores 10 GB of storage would be fine for a single-user server, but that depends on usage patterns a lot A small-scale server (tens of users) can be easily run on a cheap VDS, a single-board computer like the Raspberry Pi, or even an old Android phone. The only hard requrements for a fediverse server are a public IP address and a domain. For anything that you intend to be used by hundreds of users or more, a dedicated server or an equivalent VDS configuration is recommended.