JNI for Delhpi: Exception Message

// ==========================================================
// ====              Created By Nekit111                 ====
// ==========================================================

var
 JNI;

function Exception (Jnienv: PJNIEnv): PAnsiChar;
var
  err: jthrowable;
  isCopy: JBoolean;
  toString: JMethodID;
  JStr: JString;
begin
  err:= jnienv^.ExceptionOccurred(Jnienv);
  isCopy:= JNI_False;
  toString:= jnienv^.GetMethodID(jnienv, jnienv^.FindClass(jnienv, 'java/lang/Object'), 'toString', '()Ljava/lang/String;');
  JStr:= jnienv^.CallObjectMethod(jnienv, err, toString);
  Result:= jnienv^.GetStringUTFChars(jnienv, JStr, @isCopy);
end;

procedure DllMain(dwReason: LongWord);
var
  VmsCount: Integer;
  JVMArray: array of PJavaVM;
  NumberOfVMs: JSize;
  JNIEnv: PJNIEnv;
  GetCreatedJavaVMs: TJNI_GetCreatedJavaVMs;
const
  BufferSize = 256;
begin
  case dwReason of
  DLL_PROCESS_ATTACH:
    begin
        GetCreatedJavaVMs := GetProcAddress(GetModuleHandle('jvm.dll'), 'JNI_GetCreatedJavaVMs');
        SetLength(JVMArray, BufferSize);
        GetCreatedJavaVMs(@JVMArray[0], BufferSize, @NumberOfVMs);
    if NumberOfVMs > 0 then
      begin
        for VmsCount := 0 to NumberOfVMs - 1 do
          begin
            JVMArray[VmsCount]^.GetEnv(JVMArray[VmsCount], @JNIEnv, JNI_VERSION_1_8);
            JVMArray[VMsCount]^.AttachCurrentThread(JVMArray[VmsCount], @JNIEnv, Nil);
            if DefineClass(Jnienv, 'ru/er_log/game/Gamer', 'D:\111\Gamer.class') = NIL then
            Showmessage(Exception(JNIEnv));
            else
            Showmessage('Class is Loaded');
          end;
      end
      else
      begin
        Exit;
      end;
    end;
  DLL_PROCESS_DETACH:
    begin
      exitcode:=noerror;
    end;
  end;
end;

begin
  DisableThreadLibraryCalls(hInstance);
  DllProc := @DllMain;
  DllProc(DLL_PROCESS_ATTACH);
end.