TruckingJobInput.java 文件源码

private void serializeLoadTimes(JsonGenerator jgen) throws IOException,
        JsonProcessingException {
    jgen.writeArrayFieldStart("LoadTimes");
    /**
     * db.hubs.aggregate([ {$project: { "loadtimes" : 1}}, {$unwind :
     * "$loadtimes"}, {$project: { "truckType" : "$loadtimes.truckType",
     * "loadTime" : "$loadtimes.loadTime"}}])
     */

    AggregationOutput agg = getDB().getCollection("hubs").aggregate(
            new BasicDBObject().append("$project",
                    new BasicDBObject().append("loadtimes", 1)),
            new BasicDBObject().append("$unwind", "$loadtimes"),
            new BasicDBObject().append(
                    "$project",
                    new BasicDBObject().append("truckType",
                            "$loadtimes.truckType").append("loadTime",
                            "$loadtimes.loadTime")));

    for (DBObject obj : agg.results()) {
        jgen.writeStartObject();
        jgen.writeStringField("hub", obj.get("_id").toString());
        jgen.writeStringField("truckType", obj.get("truckType").toString());
        jgen.writeNumberField("loadTime",
                ((Number) obj.get("loadTime")).intValue());
        jgen.writeEndObject();
    }
    jgen.writeEndArray();
}