Java Mongo QueryBuilder 예제

public List<Map<String, Object>> findList() {  

List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();

BasicDBObject document = new BasicDBObject();

Calendar cal = Calendar.getInstance();

Date now = cal.getTime();

QueryBuilder qb = new QueryBuilder();

qb.or(new QueryBuilder().put("starting_date").is(null).put("ending_date").is(null).get(), 

                new QueryBuilder().put("starting_date").lessThanEquals(now).put("ending_date").greaterThanEquals(now).get());

document.putAll(qb.get());

document.put("status", "running");

DBCursor cursor = getDbCollection().find(document).sort(new BasicDBObject("reported_time", 1));

while(cursor.hasNext()) {

list.add((Map<String, Object>) cursor.next().toMap().get("message"));

}

return list;

}

- QueryBuilder qb = new QueryBuilder(), instantiates a new QueryBuilder.

- The logic build by the QueryBuilder in the example above is;  (starting date = null and ending date = null) or (starting date >= now and ending date >= now) .  [qb.or(new QueryBuilder().put("starting_date").is(null).put("ending_date").is(null).get(), 

                new QueryBuilder().put("starting_date").lessThanEquals(now).put("ending_date").greaterThanEquals(now).get());]

- document.putAll(qb.get()) adds the logic constructed to the DBObject.