Metacat

import java.text.SimpleDateFormat;

 * 1. It will read the eml from Metacat.

 * 2. Get online URL information from eml document by DOM parser.

 * 3. Base on the URL information, this program will find the data file in

 *     the direcotry which contains the srb data file.

* 4. It will generate docid for the data file.

* 5. Upload the download srb data file to Metacat with assigned docid.

* 6. Modify the eml document with the new URL information (pointing to

 *     knb) and new version number in eml

 * 7. Update it to a new version in Metacat.

 * 8 . Go through above 7 steps for every eml document in the list.

	  private static String TABLEONLINEURL= "/eml:eml/dataset/dataTable/physical/distribution/online/url";

	  private static String SPATIALONLINEURL = "/eml:eml/dataset/spatialRaster/physical/distribution/online/url";

	  private static String PACKAGEID               ="/eml:eml/@packageId";

	  private static String KNB                           = "ecogrid://knb/";

	  private static String DATAIDPREFIX          = "IPCC";

	  private static String DOT                           = ".";

	  private static String SUCCESSLOG             = "update.log";

	  private static String ERRORLOG                = "error.log";

	  private File log = new File(SUCCESSLOG);

	  private File error = new File (ERRORLOG);

              // 5. At last upload the download srb data file to Metacat with assigned docid.

			  // 6. Modify the eml document with the new URL information (pointing to

			  // knb) and new version number in eml.

			  // 7.Update it to a new version in Metacat.

            			   String dataId = handleSingleEML(docid);

            			   String message = "Successfully update eml "+docid + " with data id "+dataId;

            			   writeLog(log, message);

            			   String message = "failed to update eml "+docid + "\n "+e.getMessage();

            			   writeLog(error, message);

	   * Here are its tasks:

	   * 5. Upload the download srb data file to Metacat with assigned docid.

	   * 6. Modify the eml document with the new URL information (pointing to

	   *     knb) and new version number in eml

	   * 7. Update it to a new version in Metacat.

	   * 

	  private String handleSingleEML(String docid) throws Exception

		  String response = metacat.login(USERNAME, PASSWORD);

		  if (response.indexOf("<login>") == -1)

			  throw new Exception("login failed "+response);

		  // 1. Reads eml document from metacat

          Node rootNode = (Node)DOMdoc.getDocumentElement();

          //2.  Gets online url information. If onlineUrl is not SRB, through an exception

          String onlineUrl = getOnLineURL(rootNode);

          //System.out.println("=================The url is "+onlineUrl);

          //3. Find the srb data file 

          String dataFileName = getDataFileNameFromURL(onlineUrl);

          //System.out.println("=================The data file is "+dataFileName);

          File dataFile = null;

          dataFile = new File(SRBDATAFILEDIR,dataFileName);

           if (!dataFile.exists())

           {

        	  throw new Exception("Couldn't find the data file in srb data directory "+dataFile);

          }

          //4. Generate docid for data file

          String dataId = generateId();

          //System.out.println("=======The docid for data file will be "+dataId);

          //5. upload data file to Metacat

          response = metacat.upload(dataId, dataFile);

          if (response.indexOf("<success>") == -1)

          {

        	  throw new Exception("Couldn't upload data file "+dataFileName +

        			  " with id "+dataId+ " into Metacat since "+response);

          }

          //6. Updates eml online url and package id in DOM

          String newId = updateEMLDoc(rootNode, docid, dataId);

          //System.out.println("The new docid is ========"+newId);

          //Put EML DOM with the new packagId and oneline url into a StringWriter and store it to String

          StringWriter stringWriter = new StringWriter();

          PrintWriter printWriter = new PrintWriter(stringWriter);

		  XMLUtilities.print(rootNode, printWriter);

		  String xml = stringWriter.toString();

		  //System.out.println("the xml is "+xml);		  

		  //7.insert new (update) EML document into Metacat

          StringReader xmlReader = new StringReader(xml);

          response = metacat.update(newId, xmlReader, null);

          if (response.indexOf("<success>") == -1)

          {

        	  throw new Exception("Upload data file "+dataFileName +

        			  " with id "+dataId+ " successfully but update eml "+newId +" failed since "+ response);

          }

          return dataId;

	  private String getOnLineURL(Node root) throws Exception

	  /*

	   * Automatically to generate a unique id for ddata file. 

	   * This id will be looked like - DATAIDPREFIX.numberBaseonTime.1, e.g

	   * IPCC.20072321.1

	   */

	  private String generateId()

	  {

		  int version = 1;

		  StringBuffer docid = new StringBuffer(DATAIDPREFIX);

		  docid.append(DOT);

		  // Create a calendar to get the date formatted properly

		  String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000);

		  SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]);

		  pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2*60*60*1000);

		  pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2*60*60*1000);

		  Calendar calendar = new GregorianCalendar(pdt);

		  Date trialTime = new Date();

		  calendar.setTime(trialTime);

			int time = 0; 

			docid.append(calendar.get(Calendar.YEAR));

			time = calendar.get(Calendar.DAY_OF_YEAR);

			if(time < 10){

				docid.append("0");

				docid.append("0");

				docid.append(time);

			} else if(time < 100) {

				docid.append("0");

				docid.append(time);

			} else {

				docid.append(time);

			}

			time = calendar.get(Calendar.HOUR_OF_DAY);

			if(time < 10){

				docid.append("0");

				docid.append(time);

			} else {

				docid.append(time);

			}

			time = calendar.get(Calendar.MINUTE);

			if(time < 10){

				docid.append("0");

				docid.append(time);

			} else {

				docid.append(time);

			}

			time = calendar.get(Calendar.SECOND);

			if(time < 10){

				docid.append("0");

				docid.append(time);

			} else {

				docid.append(time);

			}		    

			 //sometimes this number is not unique, so we append a random number

			int random = (new Double(Math.random()*100)).intValue();

			docid.append(random);

			docid.append(DOT);

			docid.append(version);

			return docid.toString();

	  }

	  /*

	   * Get data file name from online url. SRB oneline url will looks like -

	   * srb://seek:/home/beam.seek/IPCC_climate/Present/ccld6190.dat.

	   * The last part - ccld6190.dat is the file name. This method will get

	   * the file name from the give url

	   */

	  private String getDataFileNameFromURL(String onlineUrl) throws Exception

	  {

		  String dataFile = null;

		  String slash = "/";

		  if (onlineUrl != null)

		  {

			  int index = onlineUrl.lastIndexOf(slash);

			  try

			  {

			     dataFile = onlineUrl.substring(index+1);

			  }

			  catch(Exception e)

			  {

				  throw new Exception("Couldn't get data file name from the given url "+onlineUrl+

						  " since "+e.getMessage());

			  }

		  }

		  return dataFile;

	  }

	   * Update the given eml document (in DOM). There are two places to be updated 

	   * The package id will be increased 1, i.e.,  from 1 to 2. The distribution online url will

	   * point to the new ecogrid id, i.e. , ecogrid://knb/IPCC.2007.1 

	   */

	  private String updateEMLDoc(Node root, String docid, String dataId) throws Exception 

	  {

		  // update package id

		  docid = getIncreasedNewDocid(docid);

		  XMLUtilities.addAttributeNodeToDOMTree( root, PACKAGEID, docid);

	      // update online url.  oneline url should either in spatialRaster or dataTable.

		  // First try to see if spatialRaster exist or not. If not try data table

		  String newUrl = KNB+dataId; //new url looks like ecogrid://knb/IPCC.2007.1

		  boolean isSpatialRaster = true;

		  boolean isDataTable = false;

		  Node urlNode = XMLUtilities.getTextNodeWithXPath(root, SPATIALONLINEURL);

		  if (urlNode == null)

		  {

			  // has no spatialRaster 

			 isSpatialRaster = false;		

		  }

		  else

		  {

			  // has spatialRaster

			  isSpatialRaster = true;		  

		  }

		  // determin if has datable or not

		  urlNode = XMLUtilities.getTextNodeWithXPath(root,TABLEONLINEURL);

		  if (urlNode != null)

		  {

				 isDataTable = true;

		  }

		  if (isSpatialRaster && !isDataTable)

		  {

			 //only has spatialRaster and no dataTable, update spatialRaster online url

			  XMLUtilities.addTextNodeToDOMTree(root, SPATIALONLINEURL, newUrl);

		  }

		  else if (!isSpatialRaster && isDataTable)

		  {

              //only has dataTable and no spatialRaster, update dataTable online url

			  XMLUtilities.addTextNodeToDOMTree(root, TABLEONLINEURL, newUrl);

		  }

		  else

		  {

			  //some strange things happen

			  throw new Exception("The eml either has both dataTable or spatialRaster OR doesn't has any entity");

		  }

		  return docid;

	  }

	  /*

	   * Gets new docid with increased version. Docid looks like tao.1.1. The new docid will be

	   * tao.1.2.

	   */

	  private String getIncreasedNewDocid(String docid) throws Exception

	  {

		  int rev = 1;

		  String revision = null;

		  String prefix = null;

		  String newId = null;

		  if (docid != null)

		  {

			  int index = docid.lastIndexOf(DOT);

			  try

			  {

				 // Get revsion part(1)

			     revision = docid.substring(index+1);

			     // Get prefix part (tao.1.)

			     prefix    = docid.substring(0, index+1);

			     // increase version from 1 to 2

			     rev = (new Integer(revision)).intValue();

			     rev++;

			     // combines the prefix tao.1. and new revision2 to get tao.1.2

			     newId= prefix+rev;

			  }

			  catch(Exception e)

			  {

				  throw new Exception("Couldn't increase revsion number from the given docid "+docid+

						  " since "+e.getMessage());

			  }

		  }

		  return newId;

	  }

	  /*

	  /*

	   * Writes error message into log file.

	   */

	  private void writeLog(File file, String message)

	  {

	    try

	    {

	      FileOutputStream fos = new FileOutputStream(file, true);

	      PrintWriter pw = new PrintWriter(fos);

	      SimpleDateFormat formatter = new SimpleDateFormat ("yy-MM-dd HH:mm:ss");

	      java.util.Date localtime = new java.util.Date();

	      String dateString = formatter.format(localtime);

	      dateString += " :: " + message;

	      //time stamp each entry

	      pw.println(dateString);

	      pw.flush();

	      pw.close();

	      fos.close();

	    }

	    catch(Exception e)

	    {

	      System.out.println("error writing to replication log from " +

	                         "MetacatReplication.replLog: " + e.getMessage());

	      //e.printStackTrace(System.out);

	    }

	 }