Example usage for org.springframework.data.mongodb.core.mapreduce GroupBy getGroupByObject

Introduction

In this page you can find the example usage for org.springframework.data.mongodb.core.mapreduce GroupBy getGroupByObject.

Prototype

public Document getGroupByObject() 

Source Link

Document

Get the Document representation of the GroupBy .

Usage

From source file:org.springframework.data.mongodb.core.MongoTemplate.java

public <T> GroupByResults<T> group(Criteria criteria, String inputCollectionName, GroupBy groupBy,
        Class<T> entityClass) {

    DBObject dbo = groupBy.getGroupByObject();
    dbo.put("ns", inputCollectionName);

    if (criteria == null) {
        dbo.put("cond", null);
    } else {/*from  w  ww . ja  va2s .  c  om*/
        dbo.put("cond", mapper.getMappedObject(criteria.getCriteriaObject(), null));
    }
    // If initial document was a JavaScript string, potentially loaded by Spring's Resource abstraction, load it and
    // convert to DBObject

    if (dbo.containsField("initial")) {
        Object initialObj = dbo.get("initial");
        if (initialObj instanceof String) {
            String initialAsString = replaceWithResourceIfNecessary((String) initialObj);
            dbo.put("initial", JSON.parse(initialAsString));
        }
    }

    if (dbo.containsField("$reduce")) {
        dbo.put("$reduce", replaceWithResourceIfNecessary(dbo.get("$reduce").toString()));
    }
    if (dbo.containsField("$keyf")) {
        dbo.put("$keyf", replaceWithResourceIfNecessary(dbo.get("$keyf").toString()));
    }
    if (dbo.containsField("finalize")) {
        dbo.put("finalize", replaceWithResourceIfNecessary(dbo.get("finalize").toString()));
    }

    DBObject commandObject = new BasicDBObject("group", dbo);

    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug(String.format("Executing Group with DBObject [%s]", serializeToJsonSafely(commandObject)));
    }

    CommandResult commandResult = executeCommand(commandObject, getDb().getOptions());
    handleCommandError(commandResult, commandObject);

    if (LOGGER.isDebugEnabled()) {
        LOGGER.debug("Group command result = [" + commandResult + "]");
    }

    @SuppressWarnings("unchecked")
    Iterable<DBObject> resultSet = (Iterable<DBObject>) commandResult.get("retval");

    List<T> mappedResults = new ArrayList<T>();
    DbObjectCallback<T> callback = new ReadDbObjectCallback<T>(mongoConverter, entityClass);
    for (DBObject dbObject : resultSet) {
        mappedResults.add(callback.doWith(dbObject));
    }
    GroupByResults<T> groupByResult = new GroupByResults<T>(mappedResults, commandResult);
    return groupByResult;

}

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