Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2011 Regents of the University of California and the

 *              National Center for Ecological Analysis and Synthesis

 *

 *   '$Author: Serhan AKIN $'

 *     '$Date: 2009-06-13 15:28:13 +0300  $'

 *

 * This program 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.

 *

 * This program 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 this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.restservice;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Enumeration;

import java.util.Hashtable;

import java.util.TimeZone;

import java.util.Timer;

import javax.servlet.ServletContext;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;

import org.apache.log4j.Logger;

import org.dataone.client.auth.CertificateManager;

import org.dataone.service.exceptions.BaseException;

import org.dataone.service.types.Session;

import org.dataone.service.types.util.ServiceTypeUtil;

import org.jibx.runtime.JiBXException;

import edu.ucsb.nceas.metacat.MetacatHandler;

import edu.ucsb.nceas.metacat.properties.PropertyService;

import edu.ucsb.nceas.utilities.PropertyNotFoundException;

/**

 * 

 * Base class for handling D1 REST calls in Metacat

 * 

 * @author leinfelder

 */

public class D1ResourceHandler {

    /**HTTP Verb GET*/

    public static final byte GET = 1;

    /**HTTP Verb POST*/

    public static final byte POST = 2;

    /**HTTP Verb PUT*/

    public static final byte PUT = 3;

    /**HTTP Verb DELETE*/

    public static final byte DELETE = 4;

    /**HTTP Verb HEAD*/

    public static final byte HEAD = 5;

    /*

     * API Resources

     */

    protected static final String RESOURCE_OBJECTS = "object";

    protected static final String RESOURCE_FORMATS = "formats";

    protected static final String RESOURCE_META = "meta";

    protected static final String RESOURCE_SESSION = "session";

    protected static final String RESOURCE_IDENTIFIER = "identifier";

    protected static final String RESOURCE_LOG = "log";

    protected static final String RESOURCE_CHECKSUM = "checksum";

    protected static final String RESOURCE_MONITOR = "monitor";

    protected static final String RESOURCE_BASE_URL = "d1";

    protected static final String RESOURCE_REPLICATE = "replicate";

    protected static final String RESOURCE_IS_AUTHORIZED = "isAuthorized";

    protected static final String RESOURCE_ACCESS_RULES = "accessRules";

    /*

     * API Functions used as URL parameters

     */

    protected static final String FUNCTION_KEYWORD = "op";

    protected static final String FUNCTION_NAME_LOGIN = "login";

    protected static final String FUNCTION_NAME_LOGOUT = "logout";

    protected static final String FUNCTION_NAME_SET_ACCESS = "setaccess";

    protected static final String FUNCTION_NAME_ISREGISTERED = "isregistered";

    protected static final String FUNCTION_NAME_GETALLDOCS = "getalldocids";

    protected static final String FUNCTION_NAME_GETNEXTREV = "getnextrevision";

    protected static final String FUNCTION_NAME_GETNEXTOBJ = "getnextobject";

    protected static final String FUNCTION_NAME_INSERT = "insert";

    protected static final String FUNCTION_NAME_UPDATE = "update";

    protected static final String FUNCTION_NAME_GENERATE_MISSING_SYSTEM_METADATA = "generatemissingsystemmetadata";

    protected static final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");

    protected ServletContext servletContext;

    protected Logger logMetacat;

    protected MetacatHandler handler;

    protected HttpServletRequest request;

    protected HttpServletResponse response;

    protected String username;

    protected String password;

    protected String sessionId;

    protected String[] groupNames;

    protected Hashtable<String, String[]> params;

    // D1 certificate-based authentication

    protected Session session;

    /**Initializes new instance by setting servlet context,request and response*/

    public D1ResourceHandler(ServletContext servletContext,

            HttpServletRequest request, HttpServletResponse response) {

        this.servletContext = servletContext;

        this.request = request;

        this.response = response;

    }

    /**

     * This function is called from REST API servlet and handles each request 

     * 

     * @param httpVerb (GET, POST, PUT or DELETE)

     */

    public void handle(byte httpVerb) {

        logMetacat = Logger.getLogger(D1ResourceHandler.class);

        try {

            // load session from certificate in request

            session = CertificateManager.getInstance().getSession(request);

            // initialize the parameters

            params = new Hashtable<String, String[]>();

            initParams();

            // create the handler for interacting with Metacat

            Timer timer = new Timer();

            handler = new MetacatHandler(timer);

        } catch (Exception e) {

        	// TODO: more D1 structure when failing here

        	response.setStatus(400);

            printError("Incorrect resource!", response);

            logMetacat.error(e.getClass() + ": " + e.getMessage(), e);

        }

    }

		/**

     *  copies request parameters to a hashtable which is given as argument to native metacathandler functions  

     */

    protected void initParams() {

        String name = null;

        String[] value = null;

        Enumeration paramlist = request.getParameterNames();

        while (paramlist.hasMoreElements()) {

            name = (String) paramlist.nextElement();

            value = request.getParameterValues(name);

            params.put(name, value);

        }

    }

    /**

     * parse a date and return it in GMT if it ends with a 'Z'

     * @param date

     * @return

     * @throws ParseException

     */

    protected Date parseDateAndConvertToGMT(String date) throws ParseException

    {

        try

        {   //the format we want

            return dateFormat.parse(date);

        }

        catch(java.text.ParseException pe)

        {   //try another legacy format

            DateFormat dateFormat2 = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss'Z'");

            dateFormat2.setTimeZone(TimeZone.getTimeZone("GMT-0"));

            return dateFormat2.parse(date);

        }    

    }

    /**

     * serialize an object of type to out

     * @param type the class of the object to serialize (i.e. SystemMetadata.class)

     * @param object the object to serialize

     * @param out the stream to serialize it to

     * @throws JiBXException

     */

    protected void serializeServiceType(Class type, Object object, OutputStream out)

      throws JiBXException {

        ServiceTypeUtil.serializeServiceType(type, object, out);

    }

    /**

     * deserialize an object of type from is

     * @param type the class of the object to serialize (i.e. SystemMetadata.class)

     * @param is the stream to deserialize from

     * @throws JiBXException

     */

    protected Object deserializeServiceType(Class type, InputStream is)

      throws JiBXException {

        return ServiceTypeUtil.deserializeServiceType(type, is);

    }

    /**

     * locate the boundary marker for an MMP

     * @param is

     * @return

     * @throws IOException

     */

    protected static String[] findBoundaryString(InputStream is)

        throws IOException {

        String[] endResult = new String[2];

        String boundary = "";

        String searchString = "boundary=";

        byte[] b = new byte[1024];

        int numbytes = is.read(b, 0, 1024);

        while(numbytes != -1)

        {

            String s = new String(b, 0, numbytes);

            int searchStringIndex = s.indexOf(searchString);

            if(s.indexOf("\"", searchStringIndex + searchString.length() + 1) == -1)

            { //the end of the boundary is in the next byte array

                boundary = s.substring(searchStringIndex + searchString.length() + 1, s.length());

            }

            else if(!boundary.startsWith("--"))

            { //we can read the whole boundary from this byte array

                boundary = s.substring(searchStringIndex + searchString.length() + 1, 

                    s.indexOf("\"", searchStringIndex + searchString.length() + 1));

                boundary = "--" + boundary;

                endResult[0] = boundary;

                endResult[1] = s.substring(s.indexOf("\"", searchStringIndex + searchString.length() + 1) + 1,

                        s.length());

                break;

            }

            else

            { //we're now reading the 2nd byte array to get the rest of the boundary

                searchString = "\"";

                searchStringIndex = s.indexOf(searchString);

                boundary += s.substring(0, searchStringIndex);

                boundary = "--" + boundary;

                endResult[0] = boundary;

                endResult[1] = s.substring(s.indexOf("\"", searchStringIndex + searchString.length() + 1) + 1,

                        s.length());

                break;

            }

        }

        System.out.println("boundary is: '" + boundary + "'");

        return endResult;

    }

    /**

     * return the directory where temp files are stored

     * @return

     */

    protected static File getTempDirectory()

    {

        File tmpDir = null;

        Logger logMetacat = Logger.getLogger(D1ResourceHandler.class);

        try {

            tmpDir = new File(PropertyService.getProperty("application.tempDir"));

        }

        catch(PropertyNotFoundException pnfe) {

            logMetacat.error("D1ResourceHandler.writeMMPPartstoFiles: " +

                    "application.tmpDir not found.  Using /tmp instead.");

            tmpDir = new File("/tmp");

        }

        return tmpDir;

    }

    /**

     * Prints xml response

     * @param message Message to be displayed

     * @param response Servlet response that xml message will be printed 

     * */

    protected void printError(String message, HttpServletResponse response) {

        try {

            logMetacat.error("D1ResourceHandler: Printing error to servlet response: " + message);

            PrintWriter out = response.getWriter();

            response.setContentType("text/xml");

            out.println("<?xml version=\"1.0\"?>");

            out.println("<error>");

            out.println(message);

            out.println("</error>");

            out.close();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    /**

     * serialize a D1 exception using jibx

     * @param e

     * @param out

     */

    protected void serializeException(BaseException e, OutputStream out) {

        // TODO: Use content negotiation to determine which return format to use

        response.setContentType("text/xml");

        response.setStatus(e.getCode());

        logMetacat.error("D1ResourceHandler: Serializing exception with code " + e.getCode() + ": " + e.getMessage());

        e.printStackTrace();

        try {

            IOUtils.write(e.serialize(BaseException.FMT_XML), out);

        } catch (IOException e1) {

            logMetacat.error("Error writing exception to stream. " 

                    + e1.getMessage());

        }

    }

}