async-profiler vs Javadoc

async-profiler is a free, self-hosted sampling profiler for Java designed to keep overhead low and avoid safepoint bias. It works with OpenJDK and other runtimes based on the HotSpot JVM, and stack traces can include non-Java threads as well as native and kernel frames. It profiles CPU time, Java-heap and native-memory allocations, memory leaks, contended locks, and hardware or software performance counters. Documented modes include CPU, allocation, wall-clock, Java-method, and multiple-events profiling. Results can be saved as collapsed stacks, flame graphs, HTML tree views, or text; an interactive Flame Graph can be viewed in a browser. Officially maintained builds are available for Linux and macOS on x64 and arm64. Developers can use the Java API as a Maven dependency, and IntelliJ IDEA includes async-profiler in its Java Profiler settings. It can profile Java processes in Docker or LXC from inside a container or from the host. Building it requires make, GCC 7.5.0 or later or Clang 7.0.0 or later, static libstdc++, and JDK 11 or later.

Javadoc creates HTML API documentation from Java source files and is installed with the Java Development Kit (JDK). Its standard doclet describes public and protected Java types and members, including classes, interfaces, constructors, methods, and fields. It can process packages, individual source files, or both, with an option to include subpackages recursively. Alternate doclets can change the content and format of the generated output, while taglets add support for custom tags in documentation comments. The standard doclet includes DocLint to help identify common comment problems, but DocLint does not check conformance or repair errors. Oracle cautions that generated output may pose issues if it is non-conformant or contains executable content such as JavaScript. JDK 25 downloads are listed for Linux, macOS, and Windows. JDK 25 binaries are free under Oracle No-Fee Terms and Conditions through September 2028; later updates use a license that may require fees for production use beyond limited free grants.