JSON Patch to subresource collection results in SpelEvaluationException: Method size() cannot be found [DATAREST-1039]

[spring-projects-issues]

Josh Wand opened DATAREST-1039 and commented

I am trying to use JSON Patch to add a subresource to a collection.. using the canonical Post -> Comment relationship with OneToMany and ManyToOne and a PostRepository, as suggested by Oliver here:
http://stackoverflow.com/questions/25311978/posting-a-onetomany-sub-resource-association-in-spring-data-rest/25451662#25451662

and following Mathias's answer here:
http://stackoverflow.com/questions/34843297/modify-onetomany-entity-in-spring-data-rest-without-its-repository/34864254#34864254.

Using 2.6.1 (as imported by Boot 1.5.2.RELEASE):

Sending PATCH to /posts/1 with:

[{"op":"add", "path":"/comments/-", "value":{"commentText":"test comment"}}];

gives the following exception:

Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1004E: Method call: Method size() cannot be found on com.example.Post type
	at org.springframework.expression.spel.ast.MethodReference.findAccessorForMethod(MethodReference.java:211) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:125) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.MethodReference.getValueInternal(MethodReference.java:85) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.OpMinus.getValueInternal(OpMinus.java:98) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.Indexer.getValueRef(Indexer.java:123) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.CompoundExpression.getValueRef(CompoundExpression.java:66) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.ast.CompoundExpression.getValueInternal(CompoundExpression.java:87) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.standard.SpelExpression.getValueType(SpelExpression.java:356) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.expression.spel.standard.SpelExpression.getValueType(SpelExpression.java:342) ~[spring-expression-4.3.7.RELEASE.jar:4.3.7.RELEASE]
	at org.springframework.data.rest.webmvc.json.patch.PatchOperation.evaluateValueFromTarget(PatchOperation.java:177) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]
	at org.springframework.data.rest.webmvc.json.patch.AddOperation.perform(AddOperation.java:43) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]
	at org.springframework.data.rest.webmvc.json.patch.Patch.apply(Patch.java:64) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]
	at org.springframework.data.rest.webmvc.config.JsonPatchHandler.applyPatch(JsonPatchHandler.java:91) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]
	at org.springframework.data.rest.webmvc.config.JsonPatchHandler.apply(JsonPatchHandler.java:83) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]
	at org.springframework.data.rest.webmvc.config.PersistentEntityResourceHandlerMethodArgumentResolver.readPatch(PersistentEntityResourceHandlerMethodArgumentResolver.java:198) ~[spring-data-rest-webmvc-2.6.1.RELEASE.jar:na]

Sample project with failing tests attached.

I can't get this basic boot/restmvc project running with Kay-M1 so unable to test there

---

Affects: 2.6.1 (Ingalls SR1)

Attachments:

• jsonpatch-collection-add.zip (102.12 kB)

Referenced from: commits 0813faf, 9ee2d43, 9a95127, 6d8caf6

Backported to: 2.6.4 (Ingalls SR4), 2.5.11 (Hopper SR11)

1 votes, 3 watchers

[spring-projects-issues]

Oliver Drotbohm commented

That should be fixed now. We now rather inspect the type than the object to find out about the type to unmarshal the incoming JSON into. Also we now transparently initialize uninitialized collections

[spring-projects-issues]

Josh Wand commented

(y)(y)