Spring Data Rest - JSON Patch Test

A repo demonstrating an issue found when using JSON Patch media type in Spring Data REST PATCH requests for updating associated resources.

See question posted in stackoverflow.

Entities

@Entity
public class Header {
    @Id
    @GeneratedValue
    private Long id;
    private String name;
}

@Entity
public class Detail {
    @Id
    @GeneratedValue
    private Long id;
    private String name;
    @ManyToOne
    @JoinColumn(name = "headerId")
    private Header header;
}

Test Setup

Start Application

No configuration required.

Download repo and start the Spring Boot application from your IDE or mvn build and start. It will listen in port 8080 by default.

Create Two Headers

curl -X POST http://localhost:8080/headers -H 'Content-Type: application/json' -d '{"name":"header-1"}'

Result:

{
  "name" : "header-1",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/headers/1"
    },
    "header" : {
      "href" : "http://localhost:8080/headers/1"
    }
  }
}

curl -X POST http://localhost:8080/headers -H 'Content-Type: application/json' -d '{"name":"header-2"}'

Result:

{
  "name" : "header-2",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/headers/2"
    },
    "header" : {
      "href" : "http://localhost:8080/headers/2"
    }
  }
}

Create Detail Associated to First Header

curl -X POST http://localhost:8080/details -H 'Content-Type: application/json' -d '{"name":"detail-1","header":"http://localhost:8080/headers/1"}'

Result:

{
  "name" : "detail-1",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/details/3"
    },
    "detail" : {
      "href" : "http://localhost:8080/details/3"
    },
    "header" : {
      "href" : "http://localhost:8080/details/3/header"
    }
  }
}

Inspect Associated Header

curl -X GET http://localhost:8080/details/3/header

Result:

{
  "name" : "header-1",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/headers/1"
    },
    "header" : {
      "href" : "http://localhost:8080/headers/1"
    }
  }
}

Tests

Update Header using PATCH (Success)

When Content-Type: application/json is used, the header association is updated successfully:

curl -X PATCH http://localhost:8080/details/3 -H 'Content-Type: application/json' -d '{"header":"http://localhost:8080/headers/2"}'

curl -X GET http://localhost:8080/details/3/header

Result:

{
  "name" : "header-2",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/headers/2"
    },
    "header" : {
      "href" : "http://localhost:8080/headers/2"
    }
  }
}

Update Header using PUT (Success)

When PUT and Content-Type: text/uri-list is used, the header association is updated successfully:

curl -X PUT http://localhost:8080/details/3/header -H 'Content-Type: text/uri-list' -d 'http://localhost:8080/headers/1'

curl -X GET http://localhost:8080/details/3/header

Result:

{
  "name" : "header-1",
  "_links" : {
    "self" : {
      "href" : "http://localhost:8080/headers/1"
    },
    "header" : {
      "href" : "http://localhost:8080/headers/1"
    }
  }
}

Update Header using PATCH/json-patch (Failure)

Using JSON Patch with a replace operation fails:

curl -X PATCH http://localhost:8080/details/3 -H 'Content-Type: application/json-patch+json' -d '[{"op":"replace","path":"/header","value":"http://localhost:8080/headers/2"}]'

Result:

{
    "cause": {
        "cause": {
            "cause": {
                "cause": {
                    "cause" : null,
                    "message" : "No converter found capable of converting from type [java.lang.String] to type [@javax.persistence.ManyToOne @javax.persistence.JoinColumn com.test.sdr.jsonpatchtest.Header]"
                },
                "message" : "EL1001E: Type conversion problem, cannot convert from java.lang.String to @javax.persistence.ManyToOne @javax.persistence.JoinColumn com.test.sdr.jsonpatchtest.Header"
            },
            "message" : "Type conversion failure"
        },
        "message" : "EL1034E: A problem occurred whilst attempting to set the property 'header': Type conversion failure"
    },
    "message" : "Could not read an object of type class com.test.sdr.jsonpatchtest.Detail from the request!; nested exception is org.springframework.expression.spel.SpelEvaluationException: EL1034E: A problem occurred whilst attempting to set the property 'header': Type conversion failure"
}