bhl.pages.handler.PagesDocumentsHandler.java Source code

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Here is the source code for bhl.pages.handler.PagesDocumentsHandler.java

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/*
 * This file is part of BHLPages.
 *
 *  BHLPages is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  BHLPages is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with BHLPages.  If not, see <http://www.gnu.org/licenses/>.
 *  (c) copyright Biodiversity Heritage Library 2015 
 *  http://www.biodiversitylibrary.org/
 */

package bhl.pages.handler;

import bhl.pages.constants.Database;
import bhl.pages.constants.JSONKeys;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import bhl.pages.exception.PagesException;
import bhl.pages.exception.DbException;
import bhl.pages.database.Connection;
import bhl.pages.database.Connector;
import org.json.simple.*;

/**
 * Get a list of documents with titles from the database
 * @author desmond
 */
public class PagesDocumentsHandler extends PagesGetHandler {
    String concoctTitle(String docid) {
        StringBuilder className = new StringBuilder();
        StringBuilder yearName = new StringBuilder();
        StringBuilder author = new StringBuilder();
        int state = 0;
        for (int i = 0; i < docid.length(); i++) {
            char token = docid.charAt(i);
            switch (state) {
            case 0: // looking for document classname
                if (Character.isDigit(token)) {
                    yearName.append(token);
                    state = 1;
                } else
                    className.append(token);
                break;
            case 1: // looking for year
                if (Character.isDigit(token) && yearName.length() < 4)
                    yearName.append(token);
                else
                    state = 2;
                break;
            case 2: // looking for author
                if (Character.isLetter(token))
                    author.append(token);
                break;
            }
        }
        StringBuilder total = new StringBuilder();
        total.append(author);
        total.append(" ");
        if (className.length() > 0 && className.charAt(className.length() - 1) == 's')
            className.setLength(className.length() - 1);
        total.append(className);
        total.append(" ");
        total.append(yearName);
        return total.toString();
    }

    /**
     * Get a pukka title from the options collection
     * @param docid the docid to get the title from
     * @return the pukka title or null
     */
    String getPukkaTitle(Connection conn, String docid) {
        try {
            String jstr = conn.getFromDbByField(Database.OPTIONS, docid, JSONKeys.DOCID);
            JSONObject jobj = (JSONObject) JSONValue.parse(jstr);
            return (String) jobj.get(JSONKeys.TITLE);
        } catch (DbException dbe) {
            return null;
        }
    }

    /**
     * Handle the request for a list of documents in the database
     * @param request the http request
     * @param response the response we will write
     * @param urn the remaining urn of the request
     * @throws PagesException 
     */
    public void handle(HttpServletRequest request, HttpServletResponse response, String urn) throws PagesException {
        try {
            Connection conn = Connector.getConnection();
            StringBuilder sb = new StringBuilder();
            sb.append("[ ");
            String[] keys = conn.getDistinctKeys(Database.DOCUMENTS, JSONKeys.IA_IDENTIFIER);
            for (int i = 0; i < keys.length; i++) {
                sb.append("{ \"docid\":");
                sb.append("\"");
                sb.append(keys[i]);
                sb.append("\", \"title\": \"");
                String title = getPukkaTitle(conn, keys[i]);
                if (title == null)
                    title = concoctTitle(keys[i]);
                sb.append(title);
                sb.append("\" }");
                if (i < keys.length - 1)
                    sb.append(",");
            }
            sb.append(" ]");
            response.setContentType("application/json;charset=UTF-8");
            response.getWriter().println(sb.toString());
        } catch (Exception e) {
            throw new PagesException(e);
        }
    }
}