Findclass result is 0 when recalling Java method using JNI in c++.++

 JavaVMOption options;
    JavaVMInitArgs vm_args;
    JNIEnv* env;
    JavaVM* jvm;
    long status;

    options.optionString = "-Djava.class.path=D:\\DEV\\javaworkspace\\Open";
    vm_args.version = JNI_VERSION_1_8;
    vm_args.nOptions = 1;
    vm_args.options = &options;

    status = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);

    jclass cls;
    jmethodID method;

    if (status != JNI_ERR)
    {
        Find cls = env->FindClass("Open"); // class to create a jclass.

        if (cls != 0)
        { 
            method = env->GetStaticMethodID(cls, "openFile", "(Ljava/lang/String;ILjava/lang/String;)V");
            if(method != 0)
            {
                jstring method_args0 = env->NewStringUTF("");  // path
                jint method_args1 = 0;  // pageIndex
                jstring method_args2 = env->NewStringUTF("");  // search term
                env->CallStaticVoidMethod(cls, method, method_args0, method_args1, method_args2);
            }

        }
        else
        {
            AfxMessageBox(_T ("Class not found")"));
            return;
        }

        jvm->DestroyJavaVM();
    }