[Prometheus JMX exporter] Export String metric as labels

[Guowei Zhang]

Hi master,
Need your help with Prometheus JMX exporter.
I have a Spring application with a Bean which has two variables: one is String and another one is Integer.
I use org.springframework.jmx.export.annotation.ManagedResource and org.springframework.jmx.export.annotation.ManagedAttribute to export them to JMX,
and then use jmx_prometheus_javaagent-0.17.0.jar to collect these custom metrics.
The result is that Integer metric is visible, but String metric not.
Then I read the source code of prometheus/jmx_exporter, and found that String is not supported yet.
So My question:

1. Is there any way to expose String metric as labels of Integer metric (without code modification, just change configuration of Spring and JMX exporter)?
2. Is there any example for exporting List<Object> ?