Hello,

That particular line of code is attempting to cast the Value of a DataTypeDescriptionType Variable to a java.lang.String, but somehow the Server has returned a java.lang.Integer Value instead and a ClassCastException is thrown. The OPC UA specification defines String as the DataType of DataTypeDescriptionType so Values of other DataTypes are not allowed. For an example of DataTypeDescriptionType Node, see /Root/Types/DataTypes/BaseDataType/Structure/AddNodesItem/Default Binary/AddNodesItem (i=7728). Note, that this BrowsePath includes non-Hierarchical References so you must enable showing them if you try to check this Node in Browser.

If possible, I would recommend fixing the Server to return String Values for all DataTypeDescriptionType Variables. If it is not possible to fix the Server, please let us know and we’ll see if we can add some workaround that would allow accepting non-String Values for DataTypeDescriptionType Variables.

To my knowledge, you have the Client-Server-Source edition of the SDK, so in the meantime you could modify com.prosysopc.ua.typedictionary.TypeDictionary class to handle casting java.lang.Integer to java.lang.String properly. In version 4.8.0, the cast to java.lang.String is on line 1063, so you would need to modify that part of the code to handle Values of other DataTypes in your Client application. You could also add some additional logging such as logging the NodeId of the DataTypeDescriptionType Variable to find which Node or Nodes on the Server are returning non-String Values to make fixing the Server easier.

Hello,

It is quite weird that the automatic call of TypeDictionary.init() did not have the same problem. I was assuming that you might have disabled the automatic call since you were calling the refresh manually, which will first clear some caches and then call init.

If the Client did perform the automatic initializing of TypeDictionary on connecting and only refreshing the TypeDictionary later fails, then perhaps the problematic DataTypeDescriptionType Variable was not yet present on the Server’s AddressSpace when the TypeDictionary was initialized for the first time. Something like that could happen if the Server allowed Clients to connect before it has finished initializing its AddressSpace.