Example usage for com.mongodb DBCursor limit

List of usage examples for com.mongodb DBCursor limit

Introduction

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

Prototype

public DBCursor limit(final int limit) 

Source Link

Document

Limits the number of elements returned.

Usage

From source file:me.yyam.mongodbutils.MongoDbOperater.java

public List<Map> find(DBCollection coll, DBObject query, DBObject order, int start, int limit) {
    DBCursor cursor = null;
    if (query == null) {
        cursor = coll.find();/*from ww w .  j  a v  a 2s  . co m*/
    } else {
        cursor = coll.find(query);
    }

    if (order != null)
        cursor = cursor.sort(order);

    if (start != 0 && limit != 0) {
        cursor.skip(start).limit(limit);
    }
    if (start == 0 && limit != 0) {
        cursor.limit(limit);
    }

    return cursor2list(cursor);
}

From source file:mongodb.findPagging.java

public static void pageResults(DBCollection collection, Integer skip) {
    BasicDBObject query = new BasicDBObject("first", "w");
    DBCursor cursor = collection.find(query);
    cursor.sort(new BasicDBObject("word", 1));
    cursor.limit(10);
    cursor.skip(skip);/*w ww  .  ja v  a 2  s  .  c  om*/
    System.out.println("Page " + new Integer(skip + 1).toString() + " to "
            + new Integer(skip + cursor.size()).toString() + ":");
    findPagging.displayCursor(cursor);
    if (cursor.size() == 10) {
        findPagging.pageResults(collection, skip + 10);
    }
}

From source file:mongodb.JavaFindFields.java

public static void includeFields(DBCollection collection, String[] fields) {
    BasicDBObject query = new BasicDBObject("first", "p");
    BasicDBObject fieldDoc = new BasicDBObject();
    for (final String field : fields) {
        fieldDoc.append(field, 1);/*from  w  w  w . ja  v  a2 s .c o  m*/
    }
    DBCursor cursor = collection.find(query, fieldDoc);
    cursor.limit(1);
    System.out.println("\nIncluding " + Arrays.toString(fields) + " fields: ");
    JavaFindFields.displayCursor(cursor);
}

From source file:mongodb.JavaFindFields.java

public static void excludeFields(DBCollection collection, String[] fields) {
    BasicDBObject query = new BasicDBObject("first", "p");
    BasicDBObject fieldDoc = new BasicDBObject();
    for (final String field : fields) {
        fieldDoc.append(field, false);/*from  w w w .  j ava  2  s  . c om*/
    }
    DBCursor cursor = collection.find(query, fieldDoc);
    cursor.limit(1);
    System.out.println("\nExcluding " + Arrays.toString(fields) + " fields: ");
    JavaFindFields.displayCursor(cursor);
}

From source file:mongodb.JavaFindLimit.java

public static void limitResults(DBCollection collection, Integer limit) {
    BasicDBObject query = new BasicDBObject("first", "p");
    DBCursor cursor = collection.find(query);
    cursor.limit(limit);
    System.out.println("\nP words Limited to " + limit.toString() + " :");
    JavaFindLimit.displayCursor(cursor);
}

From source file:mongoDB.MongoDbClientAllImagesAsByteArrays.java

License:Open Source License

@Override
public int viewTopKResources(int requesterID, int profileOwnerID, int k,
        Vector<HashMap<String, ByteIterator>> result) {
    int retVal = 0;
    if (profileOwnerID < 0 || requesterID < 0 || k < 0)
        return -1;

    com.mongodb.DB db = null;//from  w  w w. j  a v  a  2 s .  c o m

    try {
        db = mongo.getDB(database);
        db.requestStart();
        if (scanResources) {
            DBCollection collection = db.getCollection("resources");
            // find all resources that belong to profileOwnerID
            // sort them by _id desc coz we want latest ones and get the top
            // k
            DBObject q = new BasicDBObject().append("walluserid", Integer.toString(profileOwnerID));
            DBCursor queryResult = null;
            queryResult = collection.find(q);
            // DBObject s = new BasicDBObject().append("_id", -1); //desc
            DBObject s = new BasicDBObject(); // desc
            s.put("_id", -1);
            queryResult = queryResult.sort(s);
            queryResult = queryResult.limit(k);
            Iterator it = queryResult.iterator();
            while (it.hasNext()) {
                HashMap<String, ByteIterator> vals = new HashMap<String, ByteIterator>();
                DBObject oneRes = new BasicDBObject();
                oneRes.putAll((DBObject) it.next());
                vals.putAll(oneRes.toMap());
                // needed to do this so the coreworkload will not need to
                // know the datastore type
                if (vals.get("_id") != null) {
                    String tmp = vals.get("_id") + "";
                    vals.remove("_id");
                    vals.put("rid", new ObjectByteIterator(tmp.getBytes()));
                }
                if (vals.get("walluserid") != null) {
                    String tmp = vals.get("walluserid") + "";
                    vals.remove("walluserid");
                    vals.put("walluserid", new ObjectByteIterator(tmp.getBytes()));
                }
                if (vals.get("creatorid") != null) {
                    String tmp = vals.get("creatorid") + "";
                    vals.remove("creatorid");
                    vals.put("creatorid", new ObjectByteIterator(tmp.getBytes()));
                }
                result.add(vals);
            }
            queryResult.close();

        } else {
            DBCollection collection = db.getCollection("users");
            DBObject q = new BasicDBObject().append("_id", profileOwnerID);
            DBObject queryResult = null;
            queryResult = collection.findOne(q);
            String x = queryResult.get("wallResources").toString();
            if (!x.equals("[ ]")) {
                x = x.substring(1, x.length() - 1);
                String resourceIds[] = x.split(",");
                BasicDBObject query = new BasicDBObject();
                List<Integer> list = new ArrayList<Integer>();
                for (int i = resourceIds.length - 1; i >= resourceIds.length
                        - Math.min(k, resourceIds.length); i--) { // to
                    // limit
                    // it
                    list.add(Integer.parseInt(resourceIds[i].trim()));
                }
                collection = db.getCollection("resources");
                query.put("_id", new BasicDBObject("$in", list));
                DBCursor cursor = collection.find(query);
                while (cursor.hasNext()) {
                    HashMap<String, ByteIterator> vals = new HashMap<String, ByteIterator>();
                    vals.putAll(cursor.next().toMap());
                    if (vals.get("_id") != null) {
                        String tmp = vals.get("_id") + "";
                        vals.remove("_id");
                        vals.put("rid", new ObjectByteIterator(tmp.getBytes()));
                    }
                    if (vals.get("walluserid") != null) {
                        String tmp = vals.get("walluserid") + "";
                        vals.remove("walluserid");
                        vals.put("walluserid", new ObjectByteIterator(tmp.getBytes()));
                    }
                    if (vals.get("creatorid") != null) {
                        String tmp = vals.get("creatorid") + "";
                        vals.remove("creatorid");
                        vals.put("creatorid", new ObjectByteIterator(tmp.getBytes()));
                    }
                    result.add(vals);
                }
                cursor.close();
            }
        }
    } catch (Exception e) {
        System.out.println(e.toString());
        retVal = -1;
    } finally {
        if (db != null) {
            db.requestDone();
        }
    }
    return retVal;

}

From source file:net.ion.framework.db.mongo.jdbc.MongoStatement.java

License:Apache License

public ResultSet executeQuery(String sql) throws SQLException {
    // TODO//from w  w w  .  j a v  a 2s  . co  m
    // handle max rows

    DBCursor cursor = new Executor(conn.getDB(), sql).query();
    if (fetchSize > 0)
        cursor.batchSize(fetchSize);
    if (maxRows > 0)
        cursor.limit(maxRows);

    last = MClientResultSet.create(cursor);
    return last;
}

From source file:net.kamradtfamily.mongorest.AggregateServlet.java

License:GNU General Public License

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

    log.fine("doPost()");

    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;/*from  w  ww  .  j  a  va2s .  c  o m*/
    }
    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:net.kamradtfamily.mongorest.AggregateServlet.java

License:GNU General Public License

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

    log.fine("doGet()");

    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;// www  .j a v  a 2  s.  c o m
    }
    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:net.kamradtfamily.mongorest.QueryServlet.java

License:GNU General Public License

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

    log.fine("doPost()");

    // server auth
    String ret;/* ww w.j a v a 2 s.  c  om*/

    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");

}