Java 25 restricted method usage of CRT

[timomeinen]

Describe the bug

Using AWS CRT with Java 25 gives warnings:

WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::loadLibrary has been called by software.amazon.awssdk.crt.CRT in an unnamed module (jar:nested:/opt/app/app.jar/!BOOT-INF/lib/aws-crt-0.38.9.jar!/)
WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

CRT compatible with Java 25 LTS

Current Behavior

Java 25 gives runtime warnings

Reproduction Steps

Put AWS CRT in classpath and execute with Java 25

Possible Solution

No response

Additional Information/Context

No response

aws-crt-java version used

0.38.9

Java version used

25

Operating System and version

macos, linux

[bretambrose]

The Java CRT will always use JNI; removing the warning is on the user to pass in the appropriate command line option when invoking java (https://docs.oracle.com/en/java/javase/24/core/restricted-methods.html)

At best we could add a FAQ question or notice in the README, but I'm not confident that would be noticed with any degree of frequency.

[Stephane994]

I for one would love to know how to move the java CRT from the classpath to the module-path, which is what I need to do if I ONLY want to allow jni access to the CRT jar. But I have not yet done this for a project, so a README section, or a link to a blog post would help.

from: https://openjdk.org/jeps/472
Enabling native access more selectively
The --enable-native-access=ALL-UNNAMED option is coarse-grained: It lifts native access restrictions on JNI and the FFM API for all classes on the class path. To limit risk and achieve higher integrity, we recommend moving JAR files that use JNI or the FFM API to the module path. This allows native access to be enabled for those JAR files specifically, not for the class path as a whole. A JAR file can be moved from the class path to the module path without being modularized; the Java runtime will treat it as automatic module whose name is based on its filename.

[afranken]

The Java CRT will always use JNI

may I ask why this project will stay on JNI?

Project Panama was released with Java 22, and while JNI is not removed or officially deprecated from the JDK at this time, the restrictions and explicit enabling of the legacy APIs needed to use it in combination with the wording of Project Panama documentation and the JEP suggests that the Java core team wants people to move over to Project Panama APIs eventually instead of using JNI indefinitely.