On 25 Oct 2011, at 18:48, Alexander Robbins wrote:
> That code snippet isn't working because I've got a RawClient instance and its
> mapReduce method wants a MapReduceSpec. I ran into this problem while trying
> to use search also. I ended up making a search object and then serializing it
> to json and providing it to the MapReduceSpec constructor, then passing the
> resulting MapReduceSpec into the mapReduce method on RawClient. Is there a
> better way? I considered just using String.format to put the variables into a
> handwritten json string and using that to instantiate the MapReduceSpec.
>
> Thanks!
> Alex
>
> My gross method of making a MapReduceSpec:
> final Map<String, Object> mapReduceObject = new HashMap<String, Object>();
> final Map<String, Object> inputs = new HashMap<String, Object>();
> final List<Map> query = new ArrayList<Map>();
> final List<String> searchTerms = new ArrayList<String>();
> searchTerms.add(bucket);
> searchTerms.add(terms);
> inputs.put("module", "riak_search");
> inputs.put("function", "mapred_search");
> inputs.put("arg", searchTerms);
> final Map<String,String> reduce = new HashMap<String,String>();
> reduce.put("language", "erlang");
> reduce.put("module", "riak_kv_mapreduce");
> reduce.put("function", "reduce_identity");
> final Map<String,Map<String,String>> map1 = new
> HashMap<String,Map<String,String>>();
> map1.put("reduce", reduce);
> query.add(map1);
> mapReduceObject.put("inputs", inputs);
> mapReduceObject.put("query", query);
> final MapReduceSpec spec = new MapReduceSpec(new
> Gson().toJson(mapReduceObject));
OK. So the high-level libraries are there to help, even if you have a
RawClient, try this:
IndexQuery q = new BinValueQuery(BinIndex.named("docUID"), "mentions",
"5b9d1a6250dbd3e77ff004a12d06958745ee32844ad4aa668001bbe69b5efcf8");
MapReduce mr = new IndexMapReduce(YOUR_RAW_CLIENT_INSTANCE, indexQuery);
mr.addReducePhase(NamedErlangFunction.REDUCE_IDENTITY,
"{reduce_phase_only_1, true}");
MapReduceResult result = mr.execute();
Collection<String[]> r = result.getResult(String[].class);
You can do the same thing with the search map reduce
MapReduce mr = new SearchMapReduce(YOUR_RAW_CLIENT, "bucket", "your
search query");
And then use the MapReduce methods to add phases and execute as before.
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