如何从单独的线程从C++调用对象上的Java函数

public class Sample {
    public static void helloFromJava() {
        System.out.println("Hello from Java!");
    }
}

javac Sample.java
javah -jni Sample

#include <jni.h>
#include <iostream>

JNIEXPORT void JNICALL Java_Sample_helloFromJava(JNIEnv* env, jclass cls) {
    std::cout << "Hello from C++!" << std::endl;
}

int main() {
    JavaVM* jvm;
    JNIEnv* env;

    JavaVMInitArgs vmArgs;
    JavaVMOption options[1];
    options[0].optionString = "-Djava.class.path=<path_to_jar>"; // 设置Java类路径
    vmArgs.version = JNI_VERSION_1_8;
    vmArgs.nOptions = 1;
    vmArgs.options = options;
    vmArgs.ignoreUnrecognized = JNI_TRUE;

    // 创建Java虚拟机
    jint res = JNI_CreateJavaVM(&jvm, (void**)&env, &vmArgs);
    if (res != JNI_OK) {
        std::cerr << "Failed to create Java VM" << std::endl;
        return 1;
    }

    // 找到Java类
    jclass cls = env->FindClass("Sample");
    if (cls == nullptr) {
        std::cerr << "Failed to find Java class" << std::endl;
        return 1;
    }

    // 找到Java方法
    jmethodID method = env->GetStaticMethodID(cls, "helloFromJava", "()V");
    if (method == nullptr) {
        std::cerr << "Failed to find Java method" << std::endl;
        return 1;
    }

    // 调用Java方法
    env->CallStaticVoidMethod(cls, method);

    // 销毁Java虚拟机
    jvm->DestroyJavaVM();

    return 0;
}

g++ -I<path_to_jdk_include> -L<path_to_jdk_lib> -o sample sample.cpp -ljvm

./sample