[SOLR-12370] NullPointerException on MoreLikeThisComponent

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: 7.3.1
• Component/s: MoreLikeThis
• Assignee: Unassigned
• Reporter: Gilles Bodart
• Created: 17/May/18 11:21
• Updated: 08/Jun/19 15:15
• Resolved: 08/Jul/18 17:10

Description

I'm trying to use the MoreLikeThis component under a suggest call, but I receive a npe every time (here's the stacktrace)

java.lang.NullPointerException
at org.apache.solr.handler.component.MoreLikeThisComponent.process(MoreLikeThisComponent.java:127)
at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:295)
at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:177)
at org.apache.solr.core.SolrCore.execute(SolrCore.java:2503)
at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:710)
at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:516)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:382)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:326)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1751)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:582)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:226)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1180)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:512)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1112)
...

and here's the config of my requestHandlers:

<requestHandler name="/suggest" class="solr.SearchHandler" startup="lazy">
<lst name="defaults">
<str name="suggest">true</str>
<str name="suggest.count">10</str>
<str name="suggest.dictionary">default</str>
<str name="spellcheck">true</str>
<str name="spellcheck.dictionary">default</str>
<str name="spellcheck.dictionary">wordbreak</str>
<str name="spellcheck.onlyMorePopular">true</str>
<str name="spellcheck.extendedResults">true</str>
<str name="spellcheck.count">10</str>
<str name="spellcheck.collate">true</str>
<str name="spellcheck.collateExtendedResults">true</str>
<str name="spellcheck.alternativeTermCount">5</str>
<str name="spellcheck.maxResultsForSuggest">5</str>
<str name="spellcheck.maxCollationTries">10</str>
<str name="spellcheck.maxCollations">5</str>

<str name="mlt">true</str>
<str name="mlt.fl">_text_</str>

<str name="hl">on</str>
<str name="hl.fl">content description title</str>
<str name="hl.preserveMulti">true</str>
<str name="hl.encoder">html</str>
<str name="hl.simple.pre">&lt;b&gt;</str>
<str name="hl.simple.post">&lt;/b&gt;</str>
</lst>
<arr name="components">
<str>suggest</str>
<str>spellcheck</str>
<str>mlt</str>
<str>highlight</str>
</arr>
</requestHandler>

<requestHandler name="/mlt" class="solr.MoreLikeThisHandler"></requestHandler>

I also tried with 

<str name="mlt">on</str>

When I call

/mlt?df=_text_&q=pann&mlt.fl=_text_

 it works fine but with

/suggest?df=_text_&q=pann&mlt.fl=_text_

I got the npe