# Converting a FacetBuilder to Json **URL:** \ **Category:** Elasticsearch\ **Created:** [September 30, 2011, 6:11am UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485 "2011-09-30T06:11:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![leonm\_2](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/leonm_2/32/3118_2.png) [@leonm\_2](https://discuss.elastic.co/u/leonm_2)\ **Post date:** [September 30, 2011, 6:11am UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485/1 "2011-09-30T06:11:48Z")
I'm trying to write a little Unit Test to check that we setting up our objects correctly. To do this I'm setting up a FacetBuilder and convert it to Json that from where I can assert its correctness. However, when I try to convert the FacetBuilder to Json I get an Exception: TermsFacetBuilder facetBuilder = FacetBuilders.termsFacet("name").field("field"); String jsonString = facetBuilder.toXContent(XContentFactory.safeJsonBuilder(), EMPTY\_PARAMS).string(); org.elasticsearch.common.jackson.JsonGenerationException: Can not write a field name, expecting a value at org.elasticsearch.common.jackson.impl.JsonGeneratorBase.\_reportError(JsonGeneratorBase.java: 480) at org.elasticsearch.common.jackson.impl.Utf8Generator.writeFieldName(Utf8Generator.java: 270) at org.elasticsearch.common.xcontent.json.JsonXContentGenerator.writeFieldName(JsonXContentGenerator.java: 70) at org.elasticsearch.common.xcontent.XContentBuilder.field(XContentBuilder.java: 253) at org.elasticsearch.common.xcontent.XContentBuilder.startObject(XContentBuilder.java: 139) at org.elasticsearch.search.facet.terms.TermsFacetBuilder.toXContent(TermsFacetBuilder.java: 211) I tried both versions 0.17.4 and 0.17.7 with pretty consistent results (StackTrace is for 0.17.7) I fired up a debugger and stepped through the code and there is nothing that is null or otherwise broken. ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [October 2, 2011, 8:52am UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485/2 "2011-10-02T08:52:16Z")
If you just need to print the facet, you need to wrap it with startObject() ({), and endObject(}) to make it in a formal json structure. On Fri, Sep 30, 2011 at 9:11 AM, leonm [leon.messerschmidt@gmail.com](mailto:leon.messerschmidt@gmail.com) wrote: > I'm trying to write a little Unit Test to check that we setting up our > objects correctly. To do this I'm setting up a FacetBuilder and > convert it to Json that from where I can assert its correctness. > > However, when I try to convert the FacetBuilder to Json I get an > Exception: > > TermsFacetBuilder facetBuilder = > FacetBuilders.termsFacet("name").field("field"); > String jsonString = > facetBuilder.toXContent(XContentFactory.safeJsonBuilder(), > EMPTY\_PARAMS).string(); > > org.elasticsearch.common.jackson.JsonGenerationException: Can not > write a field name, expecting a value > at > > org.elasticsearch.common.jackson.impl.JsonGeneratorBase.\_reportError(JsonGeneratorBase.java: > 480) > at > > org.elasticsearch.common.jackson.impl.Utf8Generator.writeFieldName(Utf8Generator.java: > 270) > at > > org.elasticsearch.common.xcontent.json.JsonXContentGenerator.writeFieldName(JsonXContentGenerator.java: > 70) > at > > org.elasticsearch.common.xcontent.XContentBuilder.field(XContentBuilder.java: > 253) > at > > org.elasticsearch.common.xcontent.XContentBuilder.startObject(XContentBuilder.java: > 139) > at > > org.elasticsearch.search.facet.terms.TermsFacetBuilder.toXContent(TermsFacetBuilder.java: > 211) > > I tried both versions 0.17.4 and 0.17.7 with pretty consistent results > (StackTrace is for 0.17.7) > > I fired up a debugger and stepped through the code and there is > nothing that is null or otherwise broken. ---
**Author:** ![leonm\_2](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/leonm_2/32/3118_2.png) [@leonm\_2](https://discuss.elastic.co/u/leonm_2)\ **Post date:** [October 2, 2011, 11:19pm UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485/3 "2011-10-02T23:19:57Z")
Thank you, that works! One more question if you don't mind: What confused me was that a Filter Builder happily creates json without the startObject() but a Facet Builder doesn't. Is there something that I can use to predict when it is required? On Oct 2, 6:52 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > If you just need to print the facet, you need to wrap it with startObject() > ({), and endObject(}) to make it in a formal json structure. > > On Fri, Sep 30, 2011 at 9:11 AM, leonm [leon.messerschm...@gmail.com](mailto:leon.messerschm...@gmail.com) wrote: > > > I'm trying to write a little Unit Test to check that we setting up our > > objects correctly. To do this I'm setting up a FacetBuilder and > > convert it to Json that from where I can assert its correctness. > > > However, when I try to convert the FacetBuilder to Json I get an > > Exception: > > > TermsFacetBuilder facetBuilder = > > FacetBuilders.termsFacet("name").field("field"); > > String jsonString = > > facetBuilder.toXContent(XContentFactory.safeJsonBuilder(), > > EMPTY\_PARAMS).string(); > > > org.elasticsearch.common.jackson.JsonGenerationException: Can not > > write a field name, expecting a value > > at > > > org.elasticsearch.common.jackson.impl.JsonGeneratorBase.\_reportError(JsonGe neratorBase.java: > > 480) > > at > > > org.elasticsearch.common.jackson.impl.Utf8Generator.writeFieldName(Utf8Gene rator.java: > > 270) > > at > > > org.elasticsearch.common.xcontent.json.JsonXContentGenerator.writeFieldName (JsonXContentGenerator.java: > > 70) > > at > > > org.elasticsearch.common.xcontent.XContentBuilder.field(XContentBuilder.jav a: > > 253) > > at > > > org.elasticsearch.common.xcontent.XContentBuilder.startObject(XContentBuild er.java: > > 139) > > at > > > org.elasticsearch.search.facet.terms.TermsFacetBuilder.toXContent(TermsFace tBuilder.java: > > 211) > > > I tried both versions 0.17.4 and 0.17.7 with pretty consistent results > > (StackTrace is for 0.17.7) > > > I fired up a debugger and stepped through the code and there is > > nothing that is null or otherwise broken. ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [October 3, 2011, 9:33am UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485/4 "2011-10-03T09:33:21Z")
Its because of the expected stage at which those different elements (query, filter, facet) are used within the search request. Sometimes, they need to be in the form of { ... } (like filters), and sometimes, they need to be outputted like "name" : { ... } (in case of facets), to be pluggable into the the full search request. On Mon, Oct 3, 2011 at 1:19 AM, leonm [leon.messerschmidt@gmail.com](mailto:leon.messerschmidt@gmail.com) wrote: > Thank you, that works! > > One more question if you don't mind: What confused me was that a > Filter Builder happily creates json without the startObject() but a > Facet Builder doesn't. Is there something that I can use to predict > when it is required? > > On Oct 2, 6:52 pm, Shay Banon [kim...@gmail.com](mailto:kim...@gmail.com) wrote: > > > If you just need to print the facet, you need to wrap it with > > startObject() > > ({), and endObject(}) to make it in a formal json structure. > > > > On Fri, Sep 30, 2011 at 9:11 AM, leonm [leon.messerschm...@gmail.com](mailto:leon.messerschm...@gmail.com) > > wrote: > > > > > I'm trying to write a little Unit Test to check that we setting up our > > > objects correctly. To do this I'm setting up a FacetBuilder and > > > convert it to Json that from where I can assert its correctness. > > > > > However, when I try to convert the FacetBuilder to Json I get an > > > Exception: > > > > > TermsFacetBuilder facetBuilder = > > > FacetBuilders.termsFacet("name").field("field"); > > > String jsonString = > > > facetBuilder.toXContent(XContentFactory.safeJsonBuilder(), > > > EMPTY\_PARAMS).string(); > > > > > org.elasticsearch.common.jackson.JsonGenerationException: Can not > > > write a field name, expecting a value > > > at > > > > > > > org.elasticsearch.common.jackson.impl.JsonGeneratorBase.\_reportError(JsonGe > neratorBase.java: > > > > 1. at > > > > > > > org.elasticsearch.common.jackson.impl.Utf8Generator.writeFieldName(Utf8Gene > rator.java: > > > > 1. at > > > > > > > org.elasticsearch.common.xcontent.json.JsonXContentGenerator.writeFieldName > (JsonXContentGenerator.java: > > > > 1. at > > > > > > > org.elasticsearch.common.xcontent.XContentBuilder.field(XContentBuilder.jav > a: > > > > 1. at > > > > > > > org.elasticsearch.common.xcontent.XContentBuilder.startObject(XContentBuild > er.java: > > > > 1. at > > > > > > > org.elasticsearch.search.facet.terms.TermsFacetBuilder.toXContent(TermsFace > tBuilder.java: > > > > 1. > > > > > I tried both versions 0.17.4 and 0.17.7 with pretty consistent results > > > (StackTrace is for 0.17.7) > > > > > I fired up a debugger and stepped through the code and there is > > > nothing that is null or otherwise broken. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:53am UTC](https://discuss.elastic.co/t/converting-a-facetbuilder-to-json/5485/5 "2017-07-06T03:53:00Z")