You can with some hoop jumping in the current release (e.g. using 1.14 you need to define the model and optimizer in Python -
https://github.com/oracle/tribuo/blob/main/Interop/Tensorflo...). With the upcoming alpha release from the TF Java group you can train purely from Java without invoking any Python -
https://github.com/tensorflow/java-models/blob/master/tensor...