Is there any way to run embedded jar file by using jni?

Yes, it is possible to run an embedded JAR file using JNI (Java Native Interface). JNI allows you to integrate Java code with native code written in languages like C or C++. Here's an outline of the steps involved:

1. Embed the JAR file: Include the JAR file as a resource within your native code project. This can be done by adding the JAR file to the project's source files or by placing it in a specific folder within the project.

2. Extract the JAR file: In your native code, extract the embedded JAR file to a temporary location. This can be done using standard file extraction techniques available in the native language you're using (e.g., C/C++ file I/O functions).

3. Load and run the JAR file: Use JNI to load and execute the embedded JAR file from the extracted location. This involves initializing the JVM (Java Virtual Machine), creating a class loader, and invoking the desired class or method within the JAR file.

Here's a high-level example in C++ using JNI:

cppCopy code
#include <jni.h>

#include <iostream>



int main() {

    JavaVM* jvm;

    JNIEnv* env;



    // Create the JVM

    JavaVMInitArgs vmArgs;

    JavaVMOption options[1];

    options[0].optionString = "-Djava.class.path=/path/to/extracted/jarfile.jar";

    vmArgs.version = JNI_VERSION_1_8;

    vmArgs.nOptions = 1;

    vmArgs.options = options;

    vmArgs.ignoreUnrecognized = JNI_FALSE;

    jint result = JNI_CreateJavaVM(&jvm, (void**)&env, &vmArgs);

    if (result != JNI_OK) {

        std::cerr << "Failed to create JVM" << std::endl;

        return 1;

    }



    // Load and run the desired class and method

    jclass cls = env->FindClass("com/example/MyClass");

    if (cls != nullptr) {

        jmethodID method = env->GetStaticMethodID(cls, "myMethod", "()V");

        if (method != nullptr) {

            env->CallStaticVoidMethod(cls, method);

        } else {

            std::cerr << "Failed to find method" << std::endl;

        }

    } else {

        std::cerr << "Failed to find class" << std::endl;

    }



    // Destroy the JVM

    jvm->DestroyJavaVM();

    return 0;

}

This example demonstrates the basic flow of creating the JVM, loading the desired class, finding and invoking a method within that class, and finally destroying the JVM.

Remember to replace /path/to/extracted/jarfile.jar with the actual path to the extracted JAR file.

By using JNI and following a similar approach, you can run an embedded JAR file from your native code. Keep in mind that using JNI involves proper setup and management of the JVM, as well as adherence to the JNI specifications and best practices.