Supported data types for events

[Erik Gahlin]

Hi Philippe, 

The supported data types in Java are primitives, java.lang.Class, java.lang.Thread and java.lang.String. You can see the list in the toType method here 

http://hg.openjdk.java.net/jdk/jdk/file/tip/src/jdk.jfr/share/classes/jdk/jfr/internal/ASMToolkit.java

You can't use JSR-310 types, but it is possible to store durations and instants using the annotations @Timespan and @Timestamp on numeric fields.

In native, arrays are supported and it is possible to define you own composite data types, for example VirtualSpace You can see the list here:
http://hg.openjdk.java.net/jdk/jdk/file/tip/src/hotspot/share/jfr/metadata/metadata.xml

The file format only support “value types”, so it is not possible to store an array with different data types per element.

Cheers
Erik

> On 14 Apr 2019, at 20:48, Philippe Marschall <kustos at gmx.net> wrote:
> 
> Hello
> 
> I'm struggling a bit to find information about the supported data types
> for custom events. What seems to be supported are the following.
> 
> - the primitive types and their wrappers
> - java.lang.String
> - java.lang.Class
> 
> But I'm not sure what is additionally supported, eg.
> java.lang.reflect.Method doesn't seem to be supported.
> 
> Are some of the following supported
> - JSR-310 (Java Date Time API)
> - java.sql Date Time types
> - java.util.Calendar
> - arrays or collections of the above types
> 
> Cheers
> Philippe