Question

我使用JNI对Java类进行C调用。其中一个Java类加载DLL，使用SWIG生成的代码调用该DLL。

问题是：当我在C中调用调用DLL的Java类时，我什么也得不到，它不起作用。

不幸的是，我无法看到背后的错误。

我该如何解决这个问题？谢谢！

以下是我使用的代码：

 /*
 * java method that loads the DLL and that is called from C
 * in the function "createInstance"(see below)
*/
public void loadIsystem(){
    System.load("c:\\_MksProj\\TestHarness\\lib\\IConnectJNI.dll");
    //System.loadLibrary(IConnectJNI);
    ConnectionMgr connection = new ConnectionMgr();
}

/*
 * the ConnectionMgr constructor
 * makes a call to the SWIG created wrapper "connectJNI"
 * and constructs the object. The most recently DLL is used.
 * here the call gets broken
 */
  public ConnectionMgr() {
      this(connectJNI.new_ConnectionMgr__SWIG_0(), true);
      //System.out.println("connectJNI.new_ConnectionMgr__SWIG_0()");
  }


  /*C code that calls the Java method(the env var is already instantiated)
  *the call gets broken when the "connection" instance is created:
  *ConnectionMgr connection = new ConnectionMgr();
  *in the loadSystem method
  */
  jobject createInstance(JNIEnv* env, char * className, char * contsructorSignature, ...)
  {
    jclass myclz = (*env)->FindClass(env, className);
    jmethodID cons = (*env)->GetMethodID(env, myclz, "<init>", contsructorSignature);
    jobject scObject = (*env)->NewObject(env, myclz, cons);

    printf("class: %d\n", myclz);
    printf("constructor: %d\n", cons);
    printf("instance: %d\n", scObject);

    jmethodID scMethod1 = (*env)->GetMethodID(env, myclz, "loadIsystem", "()V");
    (*env)->CallVoidMethod(env, scObject, scMethod1);

    return scObject;
  }

可能与此问题有关： call Java from Matlab

C调用（通过JNI）调用DLL的Java（通过SWIG）

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