formatter.handler.FormatterHandler.java Source code

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Here is the source code for formatter.handler.FormatterHandler.java

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/*
 * This file is part of Formatter.
 *
 *  Formatter 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.
 *
 *  Formatter 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 Formatter.  If not, see <http://www.gnu.org/licenses/>.
 *  (c) copyright Desmond Schmidt 2015
 */

package formatter.handler;

import calliope.core.URLEncoder;
import calliope.core.constants.Database;
import calliope.core.constants.Formats;
import calliope.core.constants.JSONKeys;
import calliope.core.database.Connector;
import formatter.exception.FormatterException;
import formatter.path.Path;
import java.util.ArrayList;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.nio.charset.Charset;
import org.json.simple.JSONObject;
import org.json.simple.JSONValue;

/**
 * Abstract super-class for all handlers: PUT, POST, DELETE, GET
 * @author ddos
 */
abstract public class FormatterHandler {
    protected String encoding;
    protected String version1;
    protected String docid;

    public FormatterHandler() {
        this.encoding = Charset.defaultCharset().name();
    }

    public abstract void handle(HttpServletRequest request, HttpServletResponse response, String urn)
            throws FormatterException;

    /**
     * Fetch a single style text
     * @param style the path to the style in the corform database
     * @return the text of the style
     */
    /**
    * Get the document body of the given urn or null
    * @param db the database where it is
    * @param docID the docID of the resource
    * @return the document body or null if not present
    */
    private static String getDocumentBody(String db, String docID) throws FormatterException {
        try {
            String jStr = Connector.getConnection().getFromDb(db, docID);
            if (jStr != null) {
                JSONObject jDoc = (JSONObject) JSONValue.parse(jStr);
                if (jDoc != null) {
                    Object body = jDoc.get(JSONKeys.BODY);
                    if (body != null)
                        return body.toString();
                }
            }
            throw new Exception("document " + db + "/" + docID + " not found");
        } catch (Exception e) {
            throw new FormatterException(e);
        }
    }

    /**
     * Get a CSS style resource
     * @param style
     * @return
     * @throws FormatterException 
     */
    protected static String fetchStyle(String style) throws FormatterException {
        // 1. try to get each literal style name
        String actual = getDocumentBody(Database.CORFORM, style);
        while (actual == null) {
            // 2. add "default" to the end
            actual = getDocumentBody(Database.CORFORM, URLEncoder.append(style, Formats.DEFAULT));
            if (actual == null) {
                // 3. pop off last path component and try again
                if (style.length() > 0)
                    style = Path.chomp(style);
                else
                    throw new FormatterException("no suitable format");
            }
        }
        return actual;
    }

    /**
     * Get the actual styles from the database. Make sure we fetch something
     * @param styles an array of style ids
     * @return an array of database contents for those ids
     * @throws a AeseException only if the database is not set up
     */
    protected String[] fetchStyles(ArrayList names) throws FormatterException {
        String[] actual = new String[names.size()];
        for (int i = 0; i < names.size(); i++) {
            actual[i] = fetchStyle((String) names.get(i));
        }
        return actual;
    }

    protected String getAuthor() {
        if (docid != null) {
            String[] parts = docid.split("/");
            if (parts.length > 1)
                return parts[1];
            else
                return "";
        } else
            return "";
    }

    protected String getWork() {
        if (docid != null) {
            String[] parts = docid.split("/");
            if (parts.length > 2)
                return parts[2];
            else
                return "";
        } else
            return "";
    }

    protected String getSection() {
        if (docid != null) {
            String[] parts = docid.split("/");
            if (parts.length > 3)
                return parts[3];
            else
                return "";
        } else
            return "";
    }

    protected String getSubsection() {
        if (docid != null) {
            String[] parts = docid.split("/");
            if (parts.length > 4)
                return parts[4];
            else
                return "";
        } else
            return "";
    }

    public String guessEncoding(byte[] bytes) {
        org.mozilla.universalchardet.UniversalDetector detector = new org.mozilla.universalchardet.UniversalDetector(
                null);
        detector.handleData(bytes, 0, bytes.length);
        detector.dataEnd();
        String charset = detector.getDetectedCharset();
        if (charset == null)
            charset = checkForMac(bytes);
        if (charset == null)
            charset = "UTF-8";
        detector.reset();
        if (!charset.equals(encoding))
            encoding = charset;
        return encoding;
    }

    private String checkForMac(byte[] data) {
        int macchars = 0;
        for (int i = 0; i < data.length; i++) {
            if (data[i] >= 0xD0 && data[i] <= 0xD5) {
                macchars++;
                if (macchars > 5)
                    break;
            }
        }
        if (macchars > 5)
            return "macintosh";
        else
            return null;
    }
}