//charstringsrcstring
-sharpinclude <stdio.h>

int main() {
    char src[] = "ab";
    int len = 0;
    while (src[len] != "\0")
        lenPP;
    printf("\n(char[]){");
    for (int i = 0; i <= len - 1; iPP) {
        printf("\"%c\"", src[i]);
        if (i < len - 1)
            printf(",");
    }
    printf(",\"\\0\"}\n");
    return 0;
}

then encapsulate the char array of split into the CPP part of the code of JNI in the following manner

extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_example_MyClass_a(JNIEnv *env, jobject, jint i) {
    //...
    int char_select = (int) i;
    char *retStr = NULL;
    //
    char *str1 = (char[]) {"a","b","\0"};
    //...
    //switch
    switch (char_select) {
        case 0:
            retStr = str1;
            break;
        //...
        
    }
    //
    return env->NewStringUTF(retStr);
}

use (reflect some methods, but use the native layer to store related name fields)

public class MyClass extends Application{
    //so
    static {
        System.loadLibrary("native");
    }
    
    static native String a(int i);

    private static void x(Context context) {
        try {
            //native
            Class<?> clz1 = Class.forName(a(1));
            Method mtd1 = clz.getMethod(a(2));
            Object obj1 = mtd1.invoke(context);
            Method mtd2 = clz1.getMethod(a(3));
            String str = (String) mtd2.invoke(context);
            Field fld1 = clz1.getField(a(4));
            //...
        //    
        } catch (Exception e) {
            e.printStackTrace();
        }
    //onCreate
    @Override
    public void onCreate() {
        super.onCreate();
        x(this);
        //...
    }
}