class java.lang.Error - Invalid memory access - wrong mapping?

[Philipp Hana]

Hello,

I'm very new to JNA and would like to control a .NET App through Java (e.g. ButtonClicks,..). Therefore I got a .dll from a college which already works with JNI but not with my JNA test application.

When calling the same function he does: mylib.INSTANCE.Java_automation_JniAutomation_BindApp("D:\\dsl\\myapp.exe"); 

i get the following error:

class java.lang.Error - Invalid memory access

at com.sun.jna.Native.invokeVoid(Native Method)

at com.sun.jna.Function.invoke(Function.java:367)

at com.sun.jna.Function.invoke(Function.java:315)

at com.sun.jna.Library$Handler.invoke(Library.java:212)

at com.sun.proxy.$Proxy6.Java_automation_JniAutomation_BindApp(Unknown Source)

What I found out, that this error occurs, when the mapping is incorrect. but I can't figure out whats wrong about

The methode is loaded beforehand by a .dll.

       public interface mylib extends Library {

            mylib INSTANCE = (mylib)

                    Native.loadLibrary((Platform.isWindows() ? "automation" : "c"),

                            mylib.class);

            boolean Java_automation_JniAutomation_BindApp(String appPath);

        }

The methode in the .cpp file, which generates looks like this:

JNIEXPORT jboolean JNICALL Java_automation_JniAutomation_OpenApp(JNIEnv * env, jobject obj, jstring filePath)

{

   LPWSTR filePathLPCWSTR = JStringtoLPWSTR(env, filePath);

LPSTARTUPINFOW si;

PROCESS_INFORMATION pi;

ZeroMemory(&si, sizeof(si));

//si.cb = sizeof(si);

ZeroMemory(&pi, sizeof(pi));

BOOL open_val = CreateProcessW(NULL, filePathLPCWSTR, NULL, NULL, FALSE, 0, NULL, NULL, si, &pi);

   

   return (open_val != FALSE);

}

Would be great, if anyone could help me on this! Thanks in advance,

Philipp

ps: iam using VB 2013 Express, 64xbit to generate the .dll and Intelli IDEA 64xbit for the binding-call

[Philipp Hana]

Update:

I still couldn't figure out, why i got this error.
Anyway I am going to use the UIAutomation from Windows now to use the WPF Functions in Java. Looks promising.

Philipp

[Timothy Wall]

You need to bind JNA interfaces to methods exported from a DLL. You do NOT bind JNA interfaces to JNI functions; JNI functions are meant to be bound directly by the JVM.

Your function "JNIEXPORT jboolean JNICALL Java_automation_JniAutomation_OpenApp(JNIEnv * env, jobject obj, jstring filePath)” is a JNI function. You can have the JVM bind to it directly, you don’t need JNA for that.

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[Philipp Hana]

Thanks a lot Timothy!