[SOLR-13180] ClassCastExceptions in o.a.s.s.facet.FacetModule for valid JSON inputs that are not objects

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 7.5, 9.0
• Fix Version/s: 8.3
• Component/s: JSON Request API
• Labels: diffblue newdev

Environment

Running on Unix, using a git checkout close to master.

Steps to reproduce

 * Build commit ea2c8ba of Solr as described in the section below.
 * Build the films collection as described below.
 * Start the server using the command “./bin/solr start -f -p 8983 -s /tmp/home”
 * Request the URL above.

Compiling the server

git clone https://github.com/apache/lucene-solr
cd lucene-solr
git checkout ea2c8ba
ant compile
cd solr
ant server

Building the collection

We followed Exercise 2 from the quick start tutorial (http://lucene.apache.org/solr/guide/7_5/solr-tutorial.html#exercise-2) - for reference, I have attached a copy of the database.

mkdir -p /tmp/home
echo '<?xml version="1.0" encoding="UTF-8" ?><solr></solr>' > /tmp/home/solr.xml

In one terminal start a Solr instance in foreground:

./bin/solr start -f -p 8983 -s /tmp/home

In another terminal, create a collection of movies, with no shards and no replication:

bin/solr create -c films
curl -X POST -H 'Content-type:application/json' --data-binary '\\{"add-field": {"name":"name", "type":"text_general", "multiValued":false, "stored":true}}' http://localhost:8983/solr/films/schema
curl -X POST -H 'Content-type:application/json' --data-binary '\{"add-copy-field" : {"source":"*","dest":"_text_"}}' [http://localhost:8983/solr/films/schema]
./bin/post -c films example/films/films.json

• Assignee: Munendra S N
• Reporter: Johannes Kloos
• Created: 29/Jan/19 15:34
• Updated: 28/Sep/19 06:03
• Resolved: 28/Sep/19 06:02

Description

Requesting the following URL gives a 500 error due to a ClassCastException in o.a.s.s.f.FacetModule: http://localhost:8983/solr/films/select?json=0

The error response is caught by an uncaught ClassCastException, with the stacktrace shown here:

java.lang.ClassCastException: java.lang.Long cannot be cast to java.util.Map
at org.apache.solr.search.facet.FacetModule.prepare(FacetModule.java:78)
at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:272)

 

The cause of this bug is similar to #13178: line 78 in FacetModule reads

jsonFacet = (Map<String, Object>) json.get("facet")

and assumes that the JSON object contained in facet is a JSON object, while we only guarantee that it is a JSON value.

Line 92 semms to contain another situation like this, but I do not have a test case handy for this specific case.

This bug was found using Diffblue Microservices Testing. Find more information on this test campaign.

Issue Links

• contains: SOLR-13178 ClassCastExceptions in o.a.s.request.json.ObjectUtil for valid JSON inputs that are not objects