Example usage for com.mongodb DBCursor skip

List of usage examples for com.mongodb DBCursor skip

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Introduction

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

Prototype

public DBCursor skip(final int numberOfElements)

Source Link

Document

Discards a given number of elements at the beginning of the cursor.

Usage

From source file:com.andreig.jetty.AggregateServlet.java

License:GNU General Public License

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.fine("doPost()");

    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);// w  w w . j av  a2 s .co  m
        return;
    }

    InputStream is = req.getInputStream();
    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        error(res, SC_BAD_REQUEST, Status.get("param name missing"));
        return;
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    DB db = mongo.getDB(db_name);
    DBCollection col = db.getCollection(col_name);

    BufferedReader r = null;
    DBObject q = null, sort = null;
    try {

        r = new BufferedReader(new InputStreamReader(is));
        String data = r.readLine();
        if (data == null) {
            error(res, SC_BAD_REQUEST, Status.get("no data"));
            return;
        }
        try {
            q = (DBObject) JSON.parse(data);
        } catch (JSONParseException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse data"));
            return;
        }
        // sort param
        data = r.readLine();
        if (data != null) {
            try {
                sort = (DBObject) JSON.parse(data);
            } catch (JSONParseException e) {
                error(res, SC_BAD_REQUEST, Status.get("can not parse sort arg"));
                return;
            }
        }

    } finally {
        if (r != null)
            r.close();
    }

    DBCursor c;
    if (sort == null)
        c = col.find(q);
    else
        c = col.find(q).sort(sort);
    if (c == null) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    res.setIntHeader("X-Documents-Count", c.count());

    if (limit != null) {
        try {
            c.limit(Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            c.close();
            return;
        }
    } else
        c.limit(MAX_FIELDS_TO_RETURN);

    if (skip != null) {
        try {
            c.skip(Integer.parseInt(skip));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            c.close();
            return;
        }
    }

    StringBuilder buf = tl.get();
    // reset buf
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    out_str(req, buf.toString(), "application/json");

}

From source file:com.andreig.jetty.AggregateServlet.java

License:GNU General Public License

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.fine("doGet()");

    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);//w w  w .java 2s.co m
        return;
    }

    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        error(res, SC_BAD_REQUEST, Status.get("param name missing"));
        return;
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    DB db = mongo.getDB(db_name);
    DBCollection col = db.getCollection(col_name);

    DBCursor c = col.find();
    if (c == null) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    res.setIntHeader("X-Documents-Count", c.count());

    if (limit != null) {
        try {
            c.limit(Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            c.close();
            return;
        }
    } else
        c.limit(MAX_FIELDS_TO_RETURN);

    if (skip != null) {
        try {
            c.skip(Integer.parseInt(skip));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            c.close();
            return;
        }
    }

    StringBuilder buf = tl.get();
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    out_str(req, buf.toString(), "application/json");

}

From source file:com.andreig.jetty.QueryServlet.java

License:GNU General Public License

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.fine("doPost()");

    // server auth
    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);//  ww  w .  j  a  v  a  2 s . co m
        return;
    }

    String ret = null;

    InputStream is = req.getInputStream();
    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        String names[] = req2mongonames(req);
        if (names != null) {
            db_name = names[0];
            col_name = names[1];
        }
        if (db_name == null || col_name == null) {
            error(res, SC_BAD_REQUEST, Status.get("param name missing"));
            return;
        }
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    String _fields = req.getParameter("fields");
    String fields[] = null;
    if (_fields != null)
        fields = _fields.split("[,]");

    DB db = mongo.getDB(db_name);

    // mongo auth
    String user = req.getParameter("user");
    String passwd = req.getParameter("passwd");
    if (user != null && passwd != null && (!db.isAuthenticated())) {
        boolean auth = db.authenticate(user, passwd.toCharArray());
        if (!auth) {
            res.sendError(SC_UNAUTHORIZED);
            return;
        }
    }

    DBCollection col = db.getCollection(col_name);

    StringBuilder buf = tl.get();
    // reset buf
    buf.setLength(0);

    BufferedReader r = null;
    DBObject q = null, sort = null;

    try {

        r = new BufferedReader(new InputStreamReader(is));
        String data = r.readLine();
        if (data == null) {
            error(res, SC_BAD_REQUEST, Status.get("no data"));
            return;
        }
        try {
            q = (DBObject) JSON.parse(data);
            if (cache != null) {
                buf.append(db_name);
                buf.append(col_name);
                buf.append(data);
            }
        } catch (JSONParseException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse data"));
            return;
        }
        // sort param
        data = r.readLine();
        if (data != null) {
            try {
                sort = (DBObject) JSON.parse(data);
            } catch (JSONParseException e) {
                error(res, SC_BAD_REQUEST, Status.get("can not parse sort arg"));
                return;
            }
            if (cache != null)
                buf.append(data);
        }

    } finally {
        if (r != null)
            r.close();
    }

    // limit
    int lim;
    if (limit != null) {
        try {
            lim = Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN);
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            return;
        }
    } else {
        lim = MAX_FIELDS_TO_RETURN;
    }
    if (cache != null) {
        buf.append(";limit=");
        buf.append(lim);
    }

    // skip
    int sk = -1;
    if (skip != null) {
        try {
            sk = Integer.parseInt(skip);
            if (cache != null) {
                buf.append(";skip=");
                buf.append(sk);
            }
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            return;
        }
    }

    // fields
    if (cache != null && _fields != null) {
        buf.append(";fields=");
        buf.append(_fields);
    }

    // from cache
    String cache_key = null;
    if (cache != null) {
        cache_key = buf.toString();
        try {
            ret = (String) cache.get(cache_key);
        }
        // some wrong char in key
        catch (IllegalArgumentException e) {
            int l = buf.length();
            for (int i = 0; i < l; i++) {
                if (buf.charAt(i) == ' ')
                    buf.setCharAt(i, '*');
            }
            cache_key = buf.toString();
            ret = (String) cache.get(cache_key);
        }
        if (ret != null) {
            out_str(req, ret, "application/json");
            return;
        }
    }

    // cursor
    DBCursor c;
    if (fields != null) {
        StringBuilder sb = new StringBuilder();
        sb.append("{");
        int len = fields.length;
        for (int i = 0; i < len; i++) {
            String s = fields[i];
            sb.append('"');
            sb.append(s);
            sb.append('"');
            sb.append(":1");
            if (i != (len - 1))
                sb.append(",");
        }
        sb.append("}");
        c = col.find(q, (DBObject) JSON.parse(sb.toString()));
    } else
        c = col.find(q);

    if (c == null || c.count() == 0) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    if (sort != null)
        c.sort(sort);

    res.setIntHeader("X-Documents-Count", c.count());

    c.limit(lim);
    if (sk != -1)
        c.skip(sk);

    // reset buf
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        if (rm_id)
            o.removeField("_id");
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }
    c.close();

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    ret = buf.toString();
    if (cache != null)
        cache.set(cache_key, ret);

    out_str(req, ret, "application/json");

}

From source file:com.andreig.jetty.QueryServlet.java

License:GNU General Public License

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.fine("doGet()");

    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);//  w  ww.  j  ava  2 s .c  o  m
        return;
    }

    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        String names[] = req2mongonames(req);
        if (names != null) {
            db_name = names[0];
            col_name = names[1];
        }
        if (db_name == null || col_name == null) {
            error(res, SC_BAD_REQUEST, Status.get("param name missing"));
            return;
        }
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    DB db = mongo.getDB(db_name);

    // mongo auth
    String user = req.getParameter("user");
    String passwd = req.getParameter("passwd");
    if (user != null && passwd != null && (!db.isAuthenticated())) {
        boolean auth = db.authenticate(user, passwd.toCharArray());
        if (!auth) {
            res.sendError(SC_UNAUTHORIZED);
            return;
        }
    }

    DBCollection col = db.getCollection(col_name);

    DBCursor c = col.find();
    if (c == null || c.count() == 0) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    res.setIntHeader("X-Documents-Count", c.count());

    if (limit != null) {
        try {
            c.limit(Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            c.close();
            return;
        }
    } else
        c.limit(MAX_FIELDS_TO_RETURN);

    if (skip != null) {
        try {
            c.skip(Integer.parseInt(skip));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            c.close();
            return;
        }
    }

    StringBuilder buf = tl.get();
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        if (rm_id)
            o.removeField("_id");
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }
    c.close();

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    out_str(req, buf.toString(), "application/json");

}

From source file:com.arquivolivre.mongocom.management.CollectionManager.java

License:Apache License

/**
 * Find all documents that match the specified query in the given
 * collection.//from  w  w  w  .  j  a v  a  2  s .c  o m
 *
 * @param <A> generic type of the collection.
 * @param collectionClass
 * @param query
 * @return a list of documents.
 */
public <A extends Object> List<A> find(Class<A> collectionClass, MongoQuery query) {
    List<A> resultSet = new ArrayList<>();
    DBCursor cursor = null;
    try {
        A obj = collectionClass.newInstance();
        String collectionName = reflectCollectionName(obj);
        cursor = db.getCollection(collectionName).find(query.getQuery(), query.getConstraits());
        if (query.getSkip() > 0) {
            cursor = cursor.skip(query.getSkip());
        }
        if (query.getLimit() > 0) {
            cursor = cursor.limit(query.getLimit());
        }
        while (cursor.hasNext()) {
            DBObject objDB = cursor.next();
            loadObject(obj, objDB);
            resultSet.add(obj);
            obj = collectionClass.newInstance();
        }
    } catch (InstantiationException | IllegalAccessException | IllegalArgumentException
            | InvocationTargetException | NoSuchMethodException | SecurityException ex) {
        LOG.log(Level.SEVERE, null, ex);
    } finally {
        if (cursor != null) {
            cursor.close();
        }
    }
    return resultSet;
}

From source file:com.bbc.remarc.ws.MetadataService.java

License:Apache License

/**
 * Core random find service for entities that have metadata
 * //from  ww w  .  ja va 2 s .c o  m
 * @param db
 *            db instance
 * @param limit
 *            number of records to find
 * @param filter
 *            find records that match this filter. Can be null for no
 *            filtering
 * @param collectionName
 *            the database collection name
 * @return collection of found DBObjects
 */
protected List<DBObject> findRandom(DB db, long limit, DBObject filter, final String collectionName) {

    List<DBObject> results = new ArrayList<DBObject>();

    try {
        db.requestStart();
        Random random = new Random();
        DBCollection dbCollection = db.getCollection(collectionName);

        long maxRecords = dbCollection.count();

        if (limit > maxRecords) {
            limit = maxRecords;
        }

        for (int i = 0; i < limit; i++) {

            boolean foundUnique = false;

            int numChecked = 0;

            while (!foundUnique) {

                if (numChecked == limit) {
                    break;
                }

                int randomNumber = random.nextInt((int) dbCollection.count());

                DBObject randomRecord = null;

                if (filter == null) {
                    randomRecord = dbCollection.find().limit(-1).skip(randomNumber).next();
                } else {

                    DBCursor cursor = dbCollection.find(filter).limit(-1);

                    if (i >= cursor.count()) {
                        // we dont have enough records from the filter to
                        // match the limit
                        break;
                    }

                    randomNumber = random.nextInt((int) cursor.count());

                    randomRecord = cursor.skip(randomNumber).next();
                }

                foundUnique = resultsContains(randomRecord, results) == false;

                if (foundUnique) {
                    randomRecord.removeField("_id");
                    results.add(randomRecord);
                }
            }
        }
    } finally {
        db.requestDone();
    }
    return results;
}

From source file:com.bugull.mongo.BuguQuery.java

License:Apache License

public List<T> results() {
    DBCursor cursor = null;
    if (fieldsSpecified) {
        cursor = coll.find(condition, fields);
    } else {/* ww  w  .  j a  va 2 s. c  om*/
        cursor = coll.find(condition, keys);
    }
    if (orderBy != null) {
        cursor.sort(MapperUtil.getSort(orderBy));
    }
    if (pageNumber > 0 && pageSize > 0) {
        cursor.skip((pageNumber - 1) * pageSize).limit(pageSize);
    }
    return MapperUtil.toList(clazz, cursor);
}

From source file:com.caci.dummyserver.MongoRepository.java

public GetObjectsResult getObjects(String table, Collection<Pair<String, String>> keys,
        Collection<String> fields, Collection<Pair<String, Collection<String>>> filters,
        Collection<String> sort, Integer offset, Integer limit) {
    DB db = mongo.getDB("Objects");
    DBCollection col = db.getCollection(table);

    GetObjectsResult result = new GetObjectsResult();

    DBObject queryObject = makeQueryObject(keys, filters);
    DBCursor cursor = col.find(queryObject);
    try {/*  w ww  .  j a v  a 2  s. c  om*/
        if (sort != null && !sort.isEmpty()) {
            DBObject sortObj = new BasicDBObject();
            for (String fieldName : sort) {
                if (fieldName.startsWith("-")) {
                    sortObj.put("data." + fieldName.substring(1), -1);
                } else {
                    sortObj.put("data." + fieldName, 1);
                }
            }
            cursor.sort(sortObj);
        }

        result.setTotal(cursor.count());

        if (offset != null && offset > 0) {
            cursor.skip(offset);
        }
        if (limit != null && limit > 0) {
            cursor.limit(limit);
        }

        while (cursor.hasNext()) {
            DBObject obj = cursor.next();
            obj = pruneDBObject(getData(obj), fields);
            result.getResults().add(obj.toString());
        }
    } finally {
        cursor.close();
    }

    return result;
}

From source file:com.cyslab.craftvm.rest.mongo.AggregateServlet.java

License:GNU General Public License

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.trace("doPost()");

    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);// ww w. ja  va  2s  .  c  o m
        return;
    }

    InputStream is = req.getInputStream();
    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        error(res, SC_BAD_REQUEST, Status.get("param name missing"));
        return;
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    DB db = mongo.getDB(db_name);
    DBCollection col = db.getCollection(col_name);

    BufferedReader r = null;
    DBObject q = null, sort = null;
    try {

        r = new BufferedReader(new InputStreamReader(is));
        String data = r.readLine();
        if (data == null) {
            error(res, SC_BAD_REQUEST, Status.get("no data"));
            return;
        }
        try {
            q = (DBObject) JSON.parse(data);
        } catch (JSONParseException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse data"));
            return;
        }
        // sort param
        data = r.readLine();
        if (data != null) {
            try {
                sort = (DBObject) JSON.parse(data);
            } catch (JSONParseException e) {
                error(res, SC_BAD_REQUEST, Status.get("can not parse sort arg"));
                return;
            }
        }

    } finally {
        if (r != null)
            r.close();
    }

    DBCursor c;
    if (sort == null)
        c = col.find(q);
    else
        c = col.find(q).sort(sort);
    if (c == null) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    res.setIntHeader("X-Documents-Count", c.count());

    if (limit != null) {
        try {
            c.limit(Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            c.close();
            return;
        }
    } else
        c.limit(MAX_FIELDS_TO_RETURN);

    if (skip != null) {
        try {
            c.skip(Integer.parseInt(skip));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            c.close();
            return;
        }
    }

    StringBuilder buf = tl.get();
    // reset buf
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    out_str(req, buf.toString(), "application/json");

}

From source file:com.cyslab.craftvm.rest.mongo.AggregateServlet.java

License:GNU General Public License

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

    log.trace("doGet()");

    if (!can_read(req)) {
        res.sendError(SC_UNAUTHORIZED);//from w ww. j  a va  2  s .  co  m
        return;
    }

    String db_name = req.getParameter("dbname");
    String col_name = req.getParameter("colname");
    if (db_name == null || col_name == null) {
        error(res, SC_BAD_REQUEST, Status.get("param name missing"));
        return;
    }
    String skip = req.getParameter("skip");
    String limit = req.getParameter("limit");

    DB db = mongo.getDB(db_name);
    DBCollection col = db.getCollection(col_name);

    DBCursor c = col.find();
    if (c == null) {
        error(res, SC_NOT_FOUND, Status.get("no documents found"));
        return;
    }

    res.setIntHeader("X-Documents-Count", c.count());

    if (limit != null) {
        try {
            c.limit(Math.min(Integer.parseInt(limit), MAX_FIELDS_TO_RETURN));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse limit"));
            c.close();
            return;
        }
    } else
        c.limit(MAX_FIELDS_TO_RETURN);

    if (skip != null) {
        try {
            c.skip(Integer.parseInt(skip));
        } catch (NumberFormatException e) {
            error(res, SC_BAD_REQUEST, Status.get("can not parse skip"));
            c.close();
            return;
        }
    }

    StringBuilder buf = tl.get();
    buf.setLength(0);

    int no = 0;
    buf.append("[");
    while (c.hasNext()) {

        DBObject o = c.next();
        JSON.serialize(o, buf);
        buf.append(",");
        no++;

    }

    if (no > 0)
        buf.setCharAt(buf.length() - 1, ']');
    else
        buf.append(']');

    res.setIntHeader("X-Documents-Returned", no);

    out_str(req, buf.toString(), "application/json");

}