NullPointerException when inserting entity with read only fields

[ljrmorgan]

I have an entity with a field annotated with@ReadOnlyProperty. When trying to save an entity of that type to my database I get a NullPointerException:

Suppressed: java.lang.NullPointerException
		at org.springframework.data.r2dbc.core.DefaultReactiveDataAccessStrategy.shouldConvertArrayValue(DefaultReactiveDataAccessStrategy.java:225)
		at org.springframework.data.r2dbc.core.DefaultReactiveDataAccessStrategy.getOutboundRow(DefaultReactiveDataAccessStrategy.java:209)
		at org.springframework.data.r2dbc.core.DefaultDatabaseClient$DefaultTypedInsertSpec.exchange(DefaultDatabaseClient.java:1171)
		at org.springframework.data.r2dbc.core.DefaultDatabaseClient$DefaultTypedInsertSpec.access$1300(DefaultDatabaseClient.java:1067)
		at org.springframework.data.r2dbc.core.DefaultDatabaseClient$DefaultTypedInsertSpec$1.lambda$first$1(DefaultDatabaseClient.java:1153)
		at reactor.core.publisher.FluxFlatMap.trySubscribeScalarMap(FluxFlatMap.java:151)
		... 85 more

The issue seems to be that the MappingR2dbcConverter does correctly skip read only properties when writing properties to the OutboundRow, but DefaultReactiveDataAccessStrategy#getOutboundRow does not skip read only properties when retrieving the SettableValues from the OutboundRow.

[ljrmorgan]

I'm intending to open a PR shortly that addresses this

[ljrmorgan]

On further investigation the issue is specifically because the property is considered "collection like" (my field is a byte[]). DefaultReactiveDataAccessStrategy#shouldConvertArrayValue dereferences value even though in this case it is null. Non collection properties are not impacted because that method returns early if property.isCollectionLike() returns true

[mp911de]

Thanks a lot. The fix is merged.