Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2010 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *

 *   '$Author: jones $'

 *     '$Date: 2010-02-03 17:58:12 -0900 (Wed, 03 Feb 2010) $'

 * '$Revision: 5211 $'

 *

 * 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.metacattest;

import java.io.ByteArrayInputStream;

import java.io.InputStream;

import java.math.BigInteger;

import java.sql.SQLException;

import java.util.*;

import junit.framework.Test;

import junit.framework.TestSuite;

import org.dataone.client.v2.itk.D1Client;

import org.dataone.configuration.Settings;

import org.dataone.service.types.v1.Identifier;

import org.dataone.service.types.v1.NodeReference;

import org.dataone.service.types.v1.NodeType;

import org.dataone.service.types.v1.ObjectFormatIdentifier;

import org.dataone.service.types.v1.ObjectList;

import org.dataone.service.types.v1.Session;

import org.dataone.service.types.v1.Subject;

import org.dataone.service.types.v2.MediaType;

import org.dataone.service.types.v2.MediaTypeProperty;

import org.dataone.service.types.v2.Node;

import org.dataone.service.types.v2.NodeList;

import org.dataone.service.types.v2.SystemMetadata;

import edu.ucsb.nceas.MCTestCase;

import edu.ucsb.nceas.metacat.AccessionNumber;

import edu.ucsb.nceas.metacat.AccessionNumberException;

import edu.ucsb.nceas.metacat.IdentifierManager;

import edu.ucsb.nceas.metacat.McdbDocNotFoundException;

import edu.ucsb.nceas.metacat.client.MetacatAuthException;

import edu.ucsb.nceas.metacat.client.MetacatInaccessibleException;

import edu.ucsb.nceas.metacat.database.DBConnectionPool;

import edu.ucsb.nceas.metacat.dataone.CNodeService;

import edu.ucsb.nceas.metacat.dataone.D1NodeServiceTest;

import edu.ucsb.nceas.metacat.dataone.MNodeService;

import org.dataone.service.exceptions.InvalidSystemMetadata;

import org.dataone.service.exceptions.NotFound;

import org.dataone.service.exceptions.ServiceFailure;

public class IdentifierManagerTest extends D1NodeServiceTest {

    private String badGuid = "test:testIdThatDoesNotExist";

    public IdentifierManagerTest(String name) {

        super(name);

    }

    /**

     * Create a suite of tests to be run together

     */

    public static Test suite() {

        TestSuite suite = new TestSuite();

        suite.addTest(new IdentifierManagerTest("initialize"));

        // Test basic functions

        suite.addTest(new IdentifierManagerTest("testGetGUID"));

        suite.addTest(new IdentifierManagerTest("testGetAllLocalIds"));

        suite.addTest(new IdentifierManagerTest("testGetInstance"));

        suite.addTest(new IdentifierManagerTest("testGetLocalId"));

        suite.addTest(new IdentifierManagerTest("testGetLocalIdNotFound"));

        suite.addTest(new IdentifierManagerTest("testIdentifierExists"));

        suite.addTest(new IdentifierManagerTest("testCreateMapping"));

        suite.addTest(new IdentifierManagerTest("testGenerateLocalId"));

        suite.addTest(new IdentifierManagerTest("testGetHeadPID"));

        suite.addTest(new IdentifierManagerTest("testMediaType"));

        suite.addTest(new IdentifierManagerTest("testQuerySystemMetadata"));

        return suite;

    }

    /**

     * Initialize the connection to metacat, and insert a document to be 

     * used for testing with a known docid.

     */

    public void setUp() {

        metacatConnectionNeeded = true;

        try {

            DBConnectionPool pool = DBConnectionPool.getInstance();

        } catch (SQLException e2) {

            fail(e2.getMessage());

        }

        try {

            super.setUp();

        } catch (Exception e1) {

            fail(e1.getMessage());

        }

    }

    /**

     * test getting a guid from the systemmetadata table

     */

    public void testGetGUID()

    {

        ph("testGetGUID");

        try

        {

            IdentifierManager im = IdentifierManager.getInstance();

            String docid = insertTestDocument();

            docid = docid.substring(0, docid.lastIndexOf("."));

            String gotGuid = im.getGUID(docid, 1);

            assertNotNull(gotGuid);

        }

        catch(Exception e)

        {

            fail("Unexpected exception in testGetGUID: " + e.getMessage());

        }

    }

    /**

     * test getting a list of all local ids

     */

    public void testGetAllLocalIds()

    {

        ph("testGetAllLocalIds");

        try

        {

            List l = IdentifierManager.getInstance().getAllLocalIds();

            for(int i=0; i<l.size(); i++)

            {

                System.out.println(l.get(i));

            }

            assertTrue(l.size() > 0);

        }

        catch(Exception e)

        {

            fail("Error in testGetAllLocalIds: " + e.getMessage());

        }

    }

    /** Test that IM instances can be created. */

    public void testGetInstance() {

        ph("testGetInstance");

        IdentifierManager im = IdentifierManager.getInstance();

        assertNotNull(im);

    }

    /** Test that known LocalId's can be looked up from GUIDs. */

    public void testGetLocalId() {

        ph("testGetLocalId");

        IdentifierManager im = IdentifierManager.getInstance();

        String docidWithRev = insertTestDocument();

        String docid = docidWithRev.substring(0, docidWithRev.lastIndexOf("."));

        String guid;

        String idReturned;

        try {

            guid = im.getGUID(docid, 1);

            idReturned = im.getLocalId(guid);

            assertEquals(docidWithRev, idReturned);

        } catch (McdbDocNotFoundException e) {

            fail(e.getMessage());

        } catch (SQLException e) {

            fail(e.getMessage());

        }

    }

    /** Test that unknown LocalId's return the proper exception. */

    public void testGetLocalIdNotFound() {

        ph("testGetLocalIdNotFound");

        IdentifierManager im = IdentifierManager.getInstance();

        String idReturned;

        try {

            idReturned = im.getLocalId(badGuid);

            fail("Failed: getLocalID() should have returned an document not " + 

                 "found exception but did not.");

        } catch (McdbDocNotFoundException e) {

            assertNotNull(e);

        } catch (SQLException e) {

            fail(e.getMessage());

        }

    }

    /** 

     * Test that an identifier is present in the system when it should

     *  be, and that it is not present when it shouldn't be. 

     */

    public void testIdentifierExists() {

        ph("testIdentifierExists");

        String goodGuid  = "";

        String accString = "";

        String docid     = "";

        int rev          = 0;

        try {

          IdentifierManager im = IdentifierManager.getInstance();

          accString = insertTestDocument();

          AccessionNumber accNumber = new AccessionNumber(accString, "NONE");

          docid = accNumber.getDocid();

          rev = new Integer(accNumber.getRev());

          goodGuid = im.getGUID(docid, rev);

          assertTrue(im.identifierExists(goodGuid));

          assertFalse(im.identifierExists(badGuid));

        } catch ( McdbDocNotFoundException dnfe ) {

          fail("The document " + docid + "couldn't be found. The error was: " +

               dnfe.getMessage());

        } catch ( AccessionNumberException ane ) {

          fail("The accession number could not be created for docid" +

               accString + ". The error was: " + ane.getMessage());

        } catch ( NumberFormatException nfe ) {

          fail("The revision number could not be created for docid" + 

               accString + ". The error was: " + nfe.getMessage());

           } catch ( SQLException sqle ) {

             fail("The accession number could not be created for docid" + 

                  accString + ". The error was: " + sqle.getMessage());

        }

    }

    /**

     * Test that we are able to create mappings from guids to localIds, and that

     * improperly formatted docids generate the proper exceptions.  This also tests

     * getLocalId() and getGUID()

     */

    public void testCreateMapping() {

       ph("testCreateMapping");

       try

       {

            IdentifierManager im = IdentifierManager.getInstance();

            String docid = "test." + new Date().getTime() + ".1";

            String guid = "guid:" + docid;

            im.createMapping(guid, docid);

            String guiddocid = docid.substring(0, docid.length() - 2);

            System.out.println("guiddocid: " + guiddocid);

            String guid2 = im.getGUID(guiddocid, 1);

            assertTrue(guid2.equals(guid));

            String docid2 = im.getLocalId(guid);

            assertTrue(docid.equals(docid2));

        } catch (McdbDocNotFoundException e) {

            e.printStackTrace();

            fail("createMapping failed to create proper localId from guid: " + e.getMessage());

        } catch (SQLException e) {

            fail(e.getMessage());

        }

    }

    /**

     * test the local id creation

     */

    public void testGenerateLocalId() {

      IdentifierManager im = IdentifierManager.getInstance();

      String localid = im.generateLocalId("mynewid." + new Date().getTime(), 1);

      System.out.println("localid: " + localid);

      assertTrue(localid != null);

    }

    /**

     * Test the method - getHeadPID for a speicified SID

     */

    public void testGetHeadPID() {

        try {

            //case-1  P1(S1) <-> P2(S1), S1 = P2 (Type 1)

            Session session = getTestSession();

            Identifier guid = new Identifier();

            guid.setValue(generateDocumentId());

            InputStream object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            SystemMetadata sysmeta = createSystemMetadata(guid, session.getSubject(), object);

            String sid1= "sid."+System.nanoTime();

            Identifier seriesId = new Identifier();

            seriesId.setValue(sid1);

            System.out.println("the first sid is "+seriesId.getValue());

            sysmeta.setSeriesId(seriesId);

            MNodeService.getInstance(request).create(session, guid, object, sysmeta);

            System.out.println("the first pid is "+guid.getValue());

            Identifier head = IdentifierManager.getInstance().getHeadPID(seriesId);

            System.out.println("the head 1 is "+head.getValue());

            assertTrue(head.getValue().equals(guid.getValue()));

            assertTrue(IdentifierManager.getInstance().systemMetadataSIDExists(seriesId.getValue()));

            assertTrue(!IdentifierManager.getInstance().systemMetadataPIDExists(seriesId.getValue()));

            assertTrue(IdentifierManager.getInstance().systemMetadataPIDExists(guid.getValue()));

            assertTrue(!IdentifierManager.getInstance().systemMetadataSIDExists(guid.getValue()));

            //do a update with the same series id

            Thread.sleep(1000);

            Identifier newPid = new Identifier();

            newPid.setValue(generateDocumentId()+"1");

            System.out.println("the second pid is "+newPid.getValue());

            SystemMetadata newSysMeta = createSystemMetadata(newPid, session.getSubject(), object);

            newSysMeta.setObsoletes(guid);

            newSysMeta.setSeriesId(seriesId);

            MNodeService.getInstance(request).update(session, guid, object, newPid, newSysMeta);

            //check

            SystemMetadata meta = CNodeService.getInstance(request).getSystemMetadata(session, guid);

            assertTrue(meta.getObsoletedBy().equals(newPid));

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, newPid);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(guid));

            System.out.println("case 1: =======");

            // the pid should be the newPid when we try to get the sid1

            head = IdentifierManager.getInstance().getHeadPID(seriesId);

            assertTrue(head.getValue().equals(newPid.getValue()));

            // the pid should be null when we try to get a no-exist sid

            Identifier non_exist_sid = new Identifier();

            non_exist_sid.setValue("no-sid-exist-123qwe");

            assertTrue(IdentifierManager.getInstance().getHeadPID(non_exist_sid) == null);

            //case-2 P1(S1) ? P2(S1), S1 = P2

            // http://jenkins-1.dataone.org/documentation/unstable/API-Documentation-development/design/ContentMutability.html

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case2 = new Identifier();

            pid1_case2.setValue(generateDocumentId());

            String sid_case2_str= "sid."+System.nanoTime();

            Identifier sid_case2 = new Identifier();

            sid_case2.setValue(sid_case2_str);

            SystemMetadata sysmeta_case2 = createSystemMetadata(pid1_case2, session.getSubject(), object);

            sysmeta_case2.setSeriesId(sid_case2);

            CNodeService.getInstance(request).create(session, pid1_case2, object, sysmeta_case2);

            Thread.sleep(1000);

            Identifier pid2_case2 = new Identifier();

            pid2_case2.setValue(generateDocumentId());

            sysmeta = createSystemMetadata(pid2_case2, session.getSubject(), object);

            sysmeta.setSeriesId(sid_case2);

            try {

                CNodeService.getInstance(request).create(session, pid2_case2, object, sysmeta);

                fail("we shouldn't get here and an InvalidSystemMetacat exception should be thrown.");

            } catch (Exception e) {

                System.out.println("case 2======= Invalid system metadata to insert the second object");

                //check 

                meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid1_case2);

                assertTrue(meta.getObsoletedBy() == null);

                assertTrue(meta.getObsoletes() == null);

                // the pid should be the newPid when we try to get the sid1

                head = IdentifierManager.getInstance().getHeadPID(sid_case2);

                assertTrue(head.getValue().equals(pid1_case2.getValue()));

            } 

            //case-3  P1(S1) <- P2(S1), S1 = P2, Discouraged, but not error condition, S1 = P2 (P1 and P2 are type 1 ends, not an ideal chain )

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case3 = new Identifier();

            pid1_case3.setValue(generateDocumentId());

            String sid_case3_str= "sid."+System.nanoTime();

            Identifier sid_case3 = new Identifier();

            sid_case3.setValue(sid_case3_str);

            SystemMetadata sysmeta_case3 = createSystemMetadata(pid1_case3, session.getSubject(), object);

            sysmeta_case3.setSeriesId(sid_case3);

            CNodeService.getInstance(request).create(session, pid1_case3, object, sysmeta_case3);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case3 = new Identifier();

            pid2_case3.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case3 = createSystemMetadata(pid2_case3, session.getSubject(), object);

            sysmeta2_case3.setSeriesId(sid_case3);

            sysmeta2_case3.setObsoletes(pid1_case3);

            CNodeService.getInstance(request).create(session, pid2_case3, object, sysmeta2_case3);

            //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case3);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case3);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid1_case3));

            System.out.println("case 3: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case3);

            assertTrue(head.equals(pid2_case3));

            //case-4 P1(S1) <-> P2(S1) <-> P3(S2), S1 = P2 (Type 2), S2 = P3 (Type 1)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case4 = new Identifier();

            pid1_case4.setValue(generateDocumentId());

            Identifier sid_case4 = new Identifier();

            sid_case4.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta_case4 = createSystemMetadata(pid1_case4, session.getSubject(), object);

            sysmeta_case4.setSeriesId(sid_case4);

            CNodeService.getInstance(request).create(session, pid1_case4, object, sysmeta_case4);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case4 = new Identifier();

            pid2_case4.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case4 = createSystemMetadata(pid2_case4, session.getSubject(), object);

            sysmeta2_case4.setSeriesId(sid_case4);

            sysmeta2_case4.setObsoletes(pid1_case4);

            CNodeService.getInstance(request).create(session, pid2_case4, object, sysmeta2_case4);

            sysmeta_case4.setObsoletedBy(pid2_case4);

            BigInteger version = BigInteger.ONE.add(BigInteger.ONE);

            sysmeta_case4.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid1_case4, sysmeta_case4);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid3_case4 = new Identifier();

            pid3_case4.setValue(generateDocumentId());

            Identifier sid2_case4 = new Identifier();

            sid2_case4.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta3_case4 = createSystemMetadata(pid3_case4, session.getSubject(), object);

            sysmeta3_case4.setSeriesId(sid2_case4);

            sysmeta3_case4.setObsoletes(pid2_case4);

            CNodeService.getInstance(request).create(session, pid3_case4, object, sysmeta3_case4);

            sysmeta2_case4.setObsoletedBy(pid3_case4);

            version = version.add(BigInteger.ONE);

            sysmeta2_case4.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid2_case4, sysmeta2_case4);

            //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case4);

            assertTrue(meta.getObsoletedBy().equals(pid2_case4));

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case4);

            assertTrue(meta.getObsoletedBy().equals(pid3_case4));

            assertTrue(meta.getObsoletes().equals(pid1_case4));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid3_case4);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid2_case4));

            System.out.println("case 4: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case4);

            assertTrue(head.equals(pid2_case4));

            head = IdentifierManager.getInstance().getHeadPID(sid2_case4);

            assertTrue(head.equals(pid3_case4));

            //case-5 P1(S1) <- P2(S1) <- P3(S2), S1 = P2 (P1 and P2 are type 1 ends, not an ideal chain), S2 = P3 (Type 1)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case5 = new Identifier();

            pid1_case5.setValue(generateDocumentId());

            Identifier sid_case5 = new Identifier();

            sid_case5.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta1_case5 = createSystemMetadata(pid1_case5, session.getSubject(), object);

            sysmeta1_case5.setSeriesId(sid_case5);

            CNodeService.getInstance(request).create(session, pid1_case5, object, sysmeta1_case5);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case5 = new Identifier();

            pid2_case5.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case5 = createSystemMetadata(pid2_case5, session.getSubject(), object);

            sysmeta2_case5.setSeriesId(sid_case5);

            sysmeta2_case5.setObsoletes(pid1_case5);

            CNodeService.getInstance(request).create(session, pid2_case5, object, sysmeta2_case5);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid3_case5 = new Identifier();

            pid3_case5.setValue(generateDocumentId());

            Identifier sid2_case5 = new Identifier();

            sid2_case5.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta3_case5 = createSystemMetadata(pid3_case5, session.getSubject(), object);

            sysmeta3_case5.setSeriesId(sid2_case5);

            sysmeta3_case5.setObsoletes(pid2_case5);

            CNodeService.getInstance(request).create(session, pid3_case5, object, sysmeta3_case5);

          //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case5);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case5);

            assertTrue(meta.getObsoletedBy() == null );

            assertTrue(meta.getObsoletes().equals(pid1_case5));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid3_case5);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid2_case5));

            System.out.println("case 5: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case5);

            assertTrue(head.equals(pid2_case5));

            head = IdentifierManager.getInstance().getHeadPID(sid2_case5);

            assertTrue(head.equals(pid3_case5));

            //case-6 P1(S1) <-> P2(S1) <-> P3(), S1 = P2 (Type 2)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case6 = new Identifier();

            pid1_case6.setValue(generateDocumentId());

            Identifier sid_case6 = new Identifier();

            sid_case6.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta_case6 = createSystemMetadata(pid1_case6, session.getSubject(), object);

            sysmeta_case6.setSeriesId(sid_case6);

            CNodeService.getInstance(request).create(session, pid1_case6, object, sysmeta_case6);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case6 = new Identifier();

            pid2_case6.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case6 = createSystemMetadata(pid2_case6, session.getSubject(), object);

            sysmeta2_case6.setSeriesId(sid_case6);

            sysmeta2_case6.setObsoletes(pid1_case6);

            CNodeService.getInstance(request).create(session, pid2_case6, object, sysmeta2_case6);

            sysmeta_case6.setObsoletedBy(pid2_case6);

            version = BigInteger.ONE.add(BigInteger.ONE);

            sysmeta_case6.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid1_case6, sysmeta_case6);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid3_case6 = new Identifier();

            pid3_case6.setValue(generateDocumentId());

            SystemMetadata sysmeta3_case6 = createSystemMetadata(pid3_case6, session.getSubject(), object);

            sysmeta3_case6.setObsoletes(pid2_case6);

            CNodeService.getInstance(request).create(session, pid3_case6, object, sysmeta3_case6);

            sysmeta2_case6.setObsoletedBy(pid3_case6);

            version = version.add(BigInteger.ONE);

            sysmeta2_case6.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid2_case6, sysmeta2_case6);

            //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case6);

            assertTrue(meta.getObsoletedBy().equals(pid2_case6));

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case6);

            assertTrue(meta.getObsoletedBy().equals(pid3_case6));

            assertTrue(meta.getObsoletes().equals(pid1_case6));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid3_case6);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid2_case6));

            System.out.println("case 6: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case6);

            assertTrue(head.equals(pid2_case6));

            //case-7 P1(S1) <-> P2(S1) <-> P3() <-> P4(S2), S1 = P2 (Type 2), S2 = P4 (Type 1)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case7 = new Identifier();

            pid1_case7.setValue(generateDocumentId());

            Identifier sid_case7 = new Identifier();

            sid_case7.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta_case7 = createSystemMetadata(pid1_case7, session.getSubject(), object);

            sysmeta_case7.setSeriesId(sid_case7);

            CNodeService.getInstance(request).create(session, pid1_case7, object, sysmeta_case7);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case7 = new Identifier();

            pid2_case7.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case7 = createSystemMetadata(pid2_case7, session.getSubject(), object);

            sysmeta2_case7.setSeriesId(sid_case7);

            sysmeta2_case7.setObsoletes(pid1_case7);

            CNodeService.getInstance(request).create(session, pid2_case7, object, sysmeta2_case7);

            sysmeta_case7.setObsoletedBy(pid2_case7);

            version = version.add(BigInteger.ONE);

            sysmeta_case7.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid1_case7, sysmeta_case7);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid3_case7 = new Identifier();

            pid3_case7.setValue(generateDocumentId());

            SystemMetadata sysmeta3_case7 = createSystemMetadata(pid3_case7, session.getSubject(), object);

            sysmeta3_case7.setObsoletes(pid2_case7);

            CNodeService.getInstance(request).create(session, pid3_case7, object, sysmeta3_case7);

            sysmeta2_case7.setObsoletedBy(pid3_case7);

            version = version.add(BigInteger.ONE);

            sysmeta2_case7.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid2_case7, sysmeta2_case7);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid4_case7 = new Identifier();

            pid4_case7.setValue(generateDocumentId());

            Identifier sid2_case7 = new Identifier();

            sid2_case7.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta4_case7 = createSystemMetadata(pid4_case7, session.getSubject(), object);

            sysmeta4_case7.setObsoletes(pid3_case7);

            sysmeta4_case7.setSeriesId(sid2_case7);

            CNodeService.getInstance(request).create(session, pid4_case7, object, sysmeta4_case7);

            sysmeta3_case7.setObsoletedBy(pid4_case7);

            version = version.add(BigInteger.ONE);

            sysmeta3_case7.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid3_case7, sysmeta3_case7);

            //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case7);

            assertTrue(meta.getObsoletedBy().equals(pid2_case7));

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case7);

            assertTrue(meta.getObsoletedBy().equals(pid3_case7));

            assertTrue(meta.getObsoletes().equals(pid1_case7));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid3_case7);

            assertTrue(meta.getObsoletedBy().equals(pid4_case7));

            assertTrue(meta.getObsoletes().equals(pid2_case7));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid4_case7);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid3_case7));

            System.out.println("case 7: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case7);

            assertTrue(head.equals(pid2_case7));

            head = IdentifierManager.getInstance().getHeadPID(sid2_case7);

            assertTrue(head.equals(pid4_case7));

            //case-8  P1(S1) <-> P2(S1) -> ?? <- P4(S1), S1 = P4, (Type 1) (Error, but will happen)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case8 = new Identifier();

            pid1_case8.setValue(generateDocumentId());

            Identifier sid_case8 = new Identifier();

            sid_case8.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta_case8 = createSystemMetadata(pid1_case8, session.getSubject(), object);

            sysmeta_case8.setSeriesId(sid_case8);

            CNodeService.getInstance(request).create(session, pid1_case8, object, sysmeta_case8);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid2_case8 = new Identifier();

            pid2_case8.setValue(generateDocumentId());

            SystemMetadata sysmeta2_case8 = createSystemMetadata(pid2_case8, session.getSubject(), object);

            sysmeta2_case8.setSeriesId(sid_case8);

            sysmeta2_case8.setObsoletes(pid1_case8);

            CNodeService.getInstance(request).create(session, pid2_case8, object, sysmeta2_case8);

            sysmeta_case8.setObsoletedBy(pid2_case8);

            version = version.add(BigInteger.ONE);

            sysmeta_case8.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid1_case8, sysmeta_case8);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid3_case8 = new Identifier();

            pid3_case8.setValue(generateDocumentId());

            SystemMetadata sysmeta3_case8 = createSystemMetadata(pid3_case8, session.getSubject(), object);

            sysmeta3_case8.setObsoletes(pid2_case8);

            sysmeta3_case8.setSeriesId(sid_case8);

            CNodeService.getInstance(request).create(session, pid3_case8, object, sysmeta3_case8);

            sysmeta2_case8.setObsoletedBy(pid3_case8);

            version = version.add(BigInteger.ONE);

            sysmeta2_case8.setSerialVersion(version);

            CNodeService.getInstance(request).updateSystemMetadata(session, pid2_case8, sysmeta2_case8);

            Thread.sleep(1000);

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid4_case8 = new Identifier();

            pid4_case8.setValue(generateDocumentId());

            //Identifier sid2_case7 = new Identifier();

            //sid2_case7.setValue("sid."+System.nanoTime());

            SystemMetadata sysmeta4_case8 = createSystemMetadata(pid4_case8, session.getSubject(), object);

            sysmeta4_case8.setObsoletes(pid3_case8);

            sysmeta4_case8.setSeriesId(sid_case8);

            CNodeService.getInstance(request).create(session, pid4_case8, object, sysmeta4_case8);

            //delete pid3_case8 

            CNodeService.getInstance(request).delete(session, pid3_case8);

            try {

                CNodeService.getInstance(request).getSystemMetadata(session, pid3_case8);

                fail("The pid "+pid3_case8.getValue()+" should be deleted.");

            } catch (NotFound e) {

                //e.printStackTrace();

                assertTrue(true);

            }

            //check

            meta = CNodeService.getInstance(request).getSystemMetadata(session, pid1_case8);

            assertTrue(meta.getObsoletedBy().equals(pid2_case8));

            assertTrue(meta.getObsoletes() == null);

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid2_case8);

            assertTrue(meta.getObsoletedBy().equals(pid3_case8));

            assertTrue(meta.getObsoletes().equals(pid1_case8));

            meta =  CNodeService.getInstance(request).getSystemMetadata(session, pid4_case8);

            assertTrue(meta.getObsoletedBy() == null);

            assertTrue(meta.getObsoletes().equals(pid3_case8));

            System.out.println("case 8: =======");

            head = IdentifierManager.getInstance().getHeadPID(sid_case8);

            assertTrue(head.equals(pid4_case8));

            //case-9  P1(S1) <-> P2(S1) ?? <- P4(S1), S1 = P4 (P2 and P4 are type 1 ends, not an ideal chain)

            object = new ByteArrayInputStream("test".getBytes("UTF-8"));

            Identifier pid1_case9 = new Identifier();

            pid1_case9.setValue(generateDocumentId());