使用在C ++中导入外部jar文件的java类

Question

我已经在c ++代码中成功实现了JNI。当我导入名为xeger.jar的外部jar文件并在java代码中使用其函数时，会出现此问题。即使我使用外部库，使用ecllipse运行它时，java文件上的代码也会运行。但是当我在c ++代码中使用JNI调用它时，它不会按预期返回值。

我有以下java类

package cversion.xeger.implementation;

import nl.flotsam.xeger.Xeger;

public class StringGenerator {

    public static int giveMeNumber(int x) {
        int y = 33;
        String regex = "[1-9]\|[1-9][0-9]{1,5}\|1000000";
        Xeger generator = new Xeger(regex);
        String result = generator.generate();
        System.out.println("Hurrayyyyyyyy !!!!!!!!!!!!!!" + result);
        return y;
    }
}

我的c ++代码如下：

#include <iostream>
#include "jni.h"
#include <string.h>
#include <typeinfo>
int main()
{
      JavaVMOption options[1];
      JNIEnv *env;
      JavaVM *jvm;
      JavaVMInitArgs vm_args;
      long status;
      jclass cls;
      jmethodID mid;
      jint square;
      jboolean answer;

   // options[0].optionString = const_cast<char *>("-Djava.library.path=/usr/lib/jvm/java-8-oracle/lib/amd64:/usr/lib/jvm/java-8-oracle/jre/lib/amd64/server");
   options[0].optionString = const_cast<char *>("-Djava.class.path=/home/aaa/eclipse-workspace/xeger/target/classes:/home/aaa/Downloads/automaton-1.12/dist/automation.jar:/home/aaa/Downloads/dxeger-1.0-SNAPSHOT.jar");
   // options[0].optionString = const_cast<char *>("-Djava.class.path=/home/aaa/Desktop/classpath-try/");
   // options[0].optionString =  const_cast<char *>("-Djava -cp /home/aaa/Desktop/Untitled.jar");
   memset(&vm_args, 0, sizeof(vm_args));
   vm_args.version = JNI_VERSION_1_8;
   vm_args.nOptions = 1;
   vm_args.options = options;
   status = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args); //If JVM creation is successful then status value is zero
   std::cout<<"Status of JNI creation is : "<<status<<std::endl;

   if (status != JNI_OK)
   {
     std::cout<<"JNI creation Failed : "<<std::endl;
     return 1;
   }
   std::cout<<"JNI creation Passed : "<<std::endl;
   cls = env->FindClass("cversion/xeger/implementation/StringGenerator");  // If the class cannot be found, cls will be zero.
   std::cout<<"The class of cls is : "<<typeid(cls).name()<<std::endl;
   // cls = env->FindClass("Sample2"); 
   std::cout<<"The value of cls is : "<<cls<<std::endl;
     if(cls !=0)
     {  
        mid = env->GetStaticMethodID(cls, "giveMeNumber", "(I)I");
        std::cout<<"The value of mid is : "<<mid<<std::endl; 
         if(mid !=0)
         {  square = env->CallStaticIntMethod(cls, mid, 25);
            std::cout<<"The value of square is "<<square<<std::endl;
            printf("Result of implementation : %d
", square);
         }
     }
     jvm->DestroyJavaVM();
    return 0;
 }

当我运行c ++文件然后行：

printf("Result of intMethod: %d
", square);

它应该打印33。

现在，如果我从java文件中删除以下代码，那么它将打印33。

String regex = "[1-9]\|[1-9][0-9]{1,5}\|1000000";
Xeger generator = new Xeger(regex);
String result = generator.generate();
System.out.println("Hurrayyyyyyyy !!!!!!!!!!!!!!" + result);