Java tutorial
/* * 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.Logger; import java.util.logging.Level; @SuppressWarnings("serial") @WebServlet(name = "QueryServlet") public class QueryServlet extends SkeletonMongodbServlet { private final static int MAX_FIELDS_TO_RETURN = 10000; private static final Logger log = Logger.getLogger(QueryServlet.class.getName()); private final ThreadLocal<StringBuilder> tl = new ThreadLocal<StringBuilder>() { @Override protected synchronized StringBuilder initialValue() { return new StringBuilder(1024 * 4); } }; private final boolean rm_id = Config.mongo_remove_idfield; // -------------------------------- @Override public void init() throws ServletException { super.init(); 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()"); // server auth String ret; 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"); } // 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) { 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"); } // ------------------------------------------------- // For cross-origin requests /* @Override protected void doOptions(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException { log.fine( "options" ); Header h = req.getFirstHeader( "Access-Control-Request-Headers" ); h = req.getFirstHeader( "Access-Control-Request-Method" ); h = req.getFirstHeader( "Origin" ); res.setHeader( "Access-Control-Allow-Origin", "*" ); res.setHeader( "Access-Control-Allow-Headers", "authorization" ); res.setHeader( "Access-Control-Allow-Methods", "GET,POST,OPTIONS" ); res.setStatus( SC_OK ); } */ }