Example usage for com.mongodb DBCursor DBCursor

Introduction

In this page you can find the example usage for com.mongodb DBCursor DBCursor.

Prototype

DBCursor(final DBCollection collection, @Nullable final DBObject filter,
            final DBCollectionFindOptions findOptions, final boolean retryReads) 

Source Link

Usage

From source file:ezbake.data.mongo.HandlerForDriverFindCalls.java

License:Apache License

private QueryResultIterator handleMinCall(String collection, Object min, DBObject jsonQuery,
        ReadPreference readPref, EzSecurityToken token, AggregationOptions opts, List<DBObject> pipeline)
        throws Exception {
    Cursor cursor;// w w w . j  av a 2  s  .com
    QueryResultIterator qri;// make a agg call to get a QueryResultIterator instance

    // add $out to pipeline
    String outCollection = "min_out_" + randomAlphanumeric(8);
    pipeline.add(new BasicDBObject("$out", outCollection));
    cursor = parent_handler.handler.db.getCollection(collection).aggregateWithOut(pipeline, opts, readPref);
    if (cursor instanceof QueryResultIterator) {
        qri = (QueryResultIterator) cursor;
    } else {
        appLog.info("UNKNOWN CURSOR RETURNED FOR handleMinCall agg call: {}", cursor.toString());
        throw new Exception("$min converted to Aggregate pipeline did not return a QueryResultIterator: "
                + cursor.toString());
    }

    for (String key : ((DBObject) min).keySet()) {
        // create the index for the keys
        parent_handler.handler.db.getCollection(outCollection).createIndex(new BasicDBObject(key, 1));
    }

    cursor = new DBCursor(parent_handler.handler.db.getCollection(outCollection), new BasicDBObject(),
            new BasicDBObject(), ReadPreference.primary()).addSpecial("$min", min);

    List<DBObject> l = new ArrayList<>();
    while (cursor.hasNext()) {
        DBObject o = cursor.next();
        appLog.info("o {}", o);
        l.add(o);
    }

    qri.setIterator(l.iterator());
    qri.setCurSize(l.size());

    // drop the tmp output collection
    parent_handler.handler.db.getCollection(outCollection).drop();
    return qri;
}

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From source file:ezbake.data.mongo.HandlerForDriverFindCalls.java

License:Apache License

private QueryResultIterator handleMaxCall(String collection, Object max, DBObject jsonQuery,
        ReadPreference readPref, EzSecurityToken token, AggregationOptions opts, List<DBObject> pipeline)
        throws Exception {
    Cursor cursor;/* ww w .j  a  v  a  2 s.co m*/
    QueryResultIterator qri;// make a agg call to get a QueryResultIterator instance

    // add $out to pipeline
    String outCollection = "max_out_" + randomAlphanumeric(8);
    pipeline.add(new BasicDBObject("$out", outCollection));
    cursor = parent_handler.handler.db.getCollection(collection).aggregateWithOut(pipeline, opts, readPref);
    if (cursor instanceof QueryResultIterator) {
        qri = (QueryResultIterator) cursor;
    } else {
        appLog.info("UNKNOWN CURSOR RETURNED FOR handleMaxCall agg call: {}", cursor.toString());
        throw new Exception("$max converted to Aggregate pipeline did not return a QueryResultIterator: "
                + cursor.toString());
    }

    for (String key : ((DBObject) max).keySet()) {
        // create the index for the keys
        parent_handler.handler.db.getCollection(outCollection).createIndex(new BasicDBObject(key, 1));
    }

    cursor = new DBCursor(parent_handler.handler.db.getCollection(outCollection), new BasicDBObject(),
            new BasicDBObject(), ReadPreference.primary()).addSpecial("$max", max);

    List<DBObject> l = new ArrayList<>();
    while (cursor.hasNext()) {
        DBObject o = cursor.next();
        l.add(o);
    }

    qri.setIterator(l.iterator());
    qri.setCurSize(l.size());

    // drop the tmp output collection
    parent_handler.handler.db.getCollection(outCollection).drop();
    return qri;
}

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From source file:org.jongo.Find.java

License:Apache License

public <T> MongoCursor<T> map(ResultHandler<T> resultHandler) {
    DBCursor cursor = new DBCursor(collection, query.toDBObject(), getFieldsAsDBObject(), readPreference);
    for (QueryModifier modifier : modifiers) {
        modifier.modify(cursor);/*  w ww  .  j  a  va2s. c o  m*/
    }
    return new MongoCursor<T>(cursor, resultHandler);
}

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