RE: retrieve lucene "doc id"

[Ben Incani]

> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf 
> Of Yonik Seeley
> Sent: Monday, 17 December 2007 4:44 PM
> To: solr-user@lucene.apache.org
> Subject: Re: retrieve lucene "doc id"
> 
> On Dec 16, 2007 11:40 PM, Ben Incani 
> <[EMAIL PROTECTED]> wrote:
> > how do I retrieve the lucene "doc id" in a query?
> 
> Currently that's not doable... if it was though, it would be 
> a slightly dangerous feature since internal ids are transient.
> Can you explain a little more about what you are trying to do?
> 
> -Yonik
> 

Hi Yonik,

I have converted to using the Solr search interface and I am trying to
retrieve documents from a list of search results (where previously I had
used the doc id directly from the lucene query results) and the solr id
I have got currently indexed is unfortunately configured not be unique!

I do realise that lucene internal ids are transient, but for a read-only
requests (that are not cached) should be ok.  

i have hacked org.apache.solr.request.XMLWriter.writeDoc to do a
writeInt("docId", docId).

**** code snippet ****

SolrServer server = new CommonsHttpSolrServer(solrURL);
Map<String,String> params = new HashMap<String,String>();
params.put("q", searchQuery);
params.put("rows", "20");

MapSolrParams solrParams = new MapSolrParams(params);           
QueryResponse response = server.query(solrParams);

SolrDocumentList docs = response.getResults();
ArrayList<HashMap> hitsList = new ArrayList<HashMap>();

for (int i = 0; i < docs.getNumFound(); i++) {
        HashMap<String,Object> resultMap = new HashMap<String,Object>();
        SolrDocument doc = (SolrDocument)docs.get(i);
        resultMap.put("id", doc.getFieldValue("docId"));
        for(int j=0; j<resultFields.length; j++) {
                String fieldName = (String)resultFields[j];
                resultMap.put(fieldName, doc.getFieldValue(fieldName));
        }
        hitsList.add(resultMap);
}
**** code snippet ****