Spring Data REST doesn't work as expected after upgrading 1.3.0.M3 from 1.3.0.M2

[izeye]

After upgrading 1.3.0.M3 from 1.3.0.M2,

page element doesn't exist and mapped entities' _embedded doesn't exist.

This is a sample reproducing the problem:

https://github.com/izeye/organizer

With 1.3.0.M2, when visiting /links, got the following:

{
  "_links" : {
    "self" : {
      "href" : "http://localhost:18080/links"
    }
  },
  "_embedded" : {
    "links" : [ {
      "createdTime" : "2015-08-12T09:04:15.509+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "https://www.oracle.com/",
      "title" : "Java",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/1"
        },
        "tags" : {
          "href" : "http://localhost:18080/links/1/tags"
        }
      }
    }, {
      "createdTime" : "2015-08-12T09:04:15.526+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "https://spring.io/",
      "title" : "Spring",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/2"
        },
        "tags" : {
          "href" : "http://localhost:18080/links/2/tags"
        }
      }
    }, {
      "createdTime" : "2015-08-12T09:04:15.527+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "http://projects.spring.io/spring-boot/",
      "title" : "Spring Boot",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/3"
        },
        "tags" : {
          "href" : "http://localhost:18080/links/3/tags"
        }
      }
    } ]
  },
  "page" : {
    "size" : 20,
    "totalElements" : 3,
    "totalPages" : 1,
    "number" : 0
  }
}

and when visiting /links/1/tags, got the following:

{
  "_links" : {
    "self" : {
      "href" : "http://localhost:18080/links/1/tags"
    }
  },
  "_embedded" : {
    "tags" : [ {
      "createdTime" : "2015-08-12T09:04:15.346+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "name" : "java",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/tags/1"
        }
      }
    } ]
  }
}

But with 1.3.0.M3, when visiting /links, got the following:

  "_links" : {
    "self" : {
      "href" : "http://localhost:18080/links",
      "templated" : false
    }
  },
  "_embedded" : {
    "links" : [ {
      "createdTime" : "2015-08-12T08:57:35.174+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "https://www.oracle.com/",
      "title" : "Java",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/1",
          "templated" : false
        },
        "link" : {
          "href" : "http://localhost:18080/links/1",
          "templated" : false
        },
        "tags" : {
          "href" : "http://localhost:18080/links/1/tags",
          "templated" : false
        }
      }
    }, {
      "createdTime" : "2015-08-12T08:57:35.183+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "https://spring.io/",
      "title" : "Spring",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/2",
          "templated" : false
        },
        "link" : {
          "href" : "http://localhost:18080/links/2",
          "templated" : false
        },
        "tags" : {
          "href" : "http://localhost:18080/links/2/tags",
          "templated" : false
        }
      }
    }, {
      "createdTime" : "2015-08-12T08:57:35.183+0000",
      "modifiedTime" : null,
      "deletedTime" : null,
      "url" : "http://projects.spring.io/spring-boot/",
      "title" : "Spring Boot",
      "_links" : {
        "self" : {
          "href" : "http://localhost:18080/links/3",
          "templated" : false
        },
        "link" : {
          "href" : "http://localhost:18080/links/3",
          "templated" : false
        },
        "tags" : {
          "href" : "http://localhost:18080/links/3/tags",
          "templated" : false
        }
      }
    } ]
  }
}

and when visiting /links/1/tags, got the following:

{
  "_links" : {
    "self" : {
      "href" : "http://localhost:18080/links/1/tags",
      "templated" : false
    }
  }
}

[wilkinsona]

I'd be surprised if this had anything to do with Boot itself. It's more likely a side-effect of the move from Spring Data REST 2.4.0.M1 (Gosling M1) to Spring Data REST 2.4.0.RC1 (Gosling RC1). Hopefully, @olivergierke can provide some insight.

[cedricziel]

(Subscribing. Same here)

[odrotbohm]

This seems to be caused by a tweak to improve the integration with Jackson 2.6 for collections but unfortunately has the side effect of the controller method's declared return type to be used to look up the serializer instead of the value actually returned. There's a ticket in Spring Framework's JIRA.

I've created a test case in Spring HATEOAS to reproduce the error. It's a bit of a pity as we of course have test cases for the rendering, but all of them using an ObjectMapper directly and thus not checking the special set up with AbstractJackson2HttpMessageConverter.

[wilkinsona]

@cedricziel FYI, you don't need to comment to subscribe – there's a button in the Notifications section of the right-hand column (on the desktop layout).

[izeye]

I confirmed it works again with Spring Boot 1.3.0.M5 (thanks to #3758, SPR-13318). Thanks!