Linking static library with JNI

Question

Java versions prior Java 8 requires native code to be in a shared library, but I\'ve read that with Java 8 it\'s possible to use static linked libraries with JNI. I have sea

Answer 1

The Java 8 enhancement https://openjdk.java.net/jeps/178 is meant for the JVM.

Given two files:

• Main.java
• Main.c

Create libnative.so:

javac Main.java
javah Main
gcc -c Main.c
gcc -c Main.c -I /home/dx/.sdkman/candidates/java/current/include/linux -I /home/dx/.sdkman/candidates/java/current/include
gcc -shared -o libnative.so Main.o

Create libnative.a:

ar -cvq libnative.a Main.o

For each libnative.a, libnative.so test run via:

java -Djava.library.path=.  Main

Result:

• Success execution when libnative.so
• Fail execution when libnative.a

This proves that 178 is for the JVM.

References:

• https://github.com/java-native-access/jna/issues/387
• https://github.com/typelogic/jni
• https://asciinema.org/a/HTPWvr0WLyEL6iz3ahGUG1A63