net.kamradtfamily.mongorest.AggregateServlet.java Source code

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Here is the source code for net.kamradtfamily.mongorest.AggregateServlet.java

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/*
 * Copyright Andrei Goumilevski
 * This file licensed under GPLv3 for non commercial projects
 * GPLv3 text http://www.gnu.org/licenses/gpl-3.0.html
 * For commercial usage please contact me
 * gmlvsk2@gmail.com
 *
*/

package net.kamradtfamily.mongorest;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import static javax.servlet.http.HttpServletResponse.*;
import javax.servlet.ServletConfig;
import javax.servlet.annotation.WebServlet;

import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.util.JSON;
import com.mongodb.util.JSONParseException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;
import java.util.logging.Level;

import java.util.logging.Logger;

@SuppressWarnings("serial")
@WebServlet(name = "QueryServlet")
public class AggregateServlet extends SkeletonMongodbServlet {

    private final static int MAX_FIELDS_TO_RETURN = 1000;
    private static final Logger log = Logger.getLogger(AggregateServlet.class.getName());
    private final ThreadLocal<StringBuilder> tl = new ThreadLocal<StringBuilder>() {
        @Override
        protected synchronized StringBuilder initialValue() {
            return new StringBuilder(1024 * 4);
        }
    };

    // --------------------------------
    @Override
    public void init() throws ServletException {

        ServletConfig config = getServletConfig();
        String name = getServletName();
        log.log(Level.FINE, "init() {0}", name);

    }

    // --------------------------------
    @Override
    public void destroy() {

        ServletConfig config = getServletConfig();
        String name = getServletName();
        log.log(Level.FINE, "destroy() {0}", name);

    }

    // POST
    // ------------------------------------
    @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;
        }
        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");

    }

    // GET
    // ------------------------------------
    @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;
        }
        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");

    }
}