Improving transaction handling in certificate management component and cleaning up the OperationManagerImpl

components/certificate-mgt/org.wso2.carbon.certificate.mgt.cert.admin.api/src/main/java/org/wso2/carbon/certificate/mgt/cert/jaxrs/api/impl/CertificateManagementAdminServiceImpl.java

@@ -9,8 +9,8 @@ import org.wso2.carbon.certificate.mgt.cert.jaxrs.api.beans.EnrollmentCertificat
 import org.wso2.carbon.certificate.mgt.cert.jaxrs.api.beans.ErrorResponse;
 import org.wso2.carbon.certificate.mgt.cert.jaxrs.api.util.DeviceMgtAPIUtils;
 import org.wso2.carbon.certificate.mgt.cert.jaxrs.api.util.RequestValidationUtil;
-import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOException;
 import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
+import org.wso2.carbon.certificate.mgt.core.exception.CertificateManagementException;
 import org.wso2.carbon.certificate.mgt.core.exception.KeystoreException;
 import org.wso2.carbon.certificate.mgt.core.service.CertificateManagementService;
 import org.wso2.carbon.context.PrivilegedCarbonContext;
@@ -76,7 +76,7 @@ public class CertificateManagementAdminServiceImpl implements CertificateManagem
         try {
             certificateResponse = certificateService.searchCertificates(serialNumber);
             return Response.status(Response.Status.OK).entity(certificateResponse).build();
-        } catch (CertificateManagementDAOException e) {
+        } catch (CertificateManagementException e) {
             String msg = "Error occurred while converting PEM file to X509Certificate";
             log.error(msg, e);
             throw new UnexpectedServerErrorException(
@@ -106,7 +106,7 @@ public class CertificateManagementAdminServiceImpl implements CertificateManagem
             certificates.setCount(result.getRecordsTotal());
             certificates.setList((List<CertificateResponse>) result.getData());
             return Response.status(Response.Status.OK).entity(certificates).build();
-        } catch (CertificateManagementDAOException e) {
+        } catch (CertificateManagementException e) {
             String msg = "Error occurred while fetching all certificates.";
             log.error(msg, e);
             throw new UnexpectedServerErrorException(
@@ -128,7 +128,7 @@ public class CertificateManagementAdminServiceImpl implements CertificateManagem
             }
             return Response.status(Response.Status.OK).entity("Certificate that carries the serial number '" +
                     serialNumber + "' has been removed").build();
-        } catch (CertificateManagementDAOException e) {
+        } catch (CertificateManagementException e) {
             String msg = "Error occurred while converting PEM file to X509Certificate";
             log.error(msg, e);
             throw new UnexpectedServerErrorException(

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/dao/CertificateDAO.java

@@ -18,11 +18,11 @@
 
 package org.wso2.carbon.certificate.mgt.core.dao;
 
+import org.wso2.carbon.certificate.mgt.core.bean.Certificate;
 import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
 import org.wso2.carbon.device.mgt.common.PaginationRequest;
 import org.wso2.carbon.device.mgt.common.PaginationResult;
 
-import java.io.ByteArrayInputStream;
 import java.util.List;
 
 /**
@@ -37,8 +37,9 @@ public interface CertificateDAO {
      *
      * @param certificate Holds the certificate and relevant details.
      * @throws CertificateManagementDAOException
+     *
      */
-    void addCertificate(List<org.wso2.carbon.certificate.mgt.core.bean.Certificate> certificate)
+    void addCertificate(List<Certificate> certificate)
             throws CertificateManagementDAOException;
 
     /**
@@ -47,31 +48,37 @@ public interface CertificateDAO {
      * @param serialNumber Serial number of the certificate.
      * @return representation of the certificate.
      * @throws CertificateManagementDAOException
+     *
      */
-    org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse retrieveCertificate(String serialNumber
+    CertificateResponse retrieveCertificate(String serialNumber) throws CertificateManagementDAOException;
-    ) throws CertificateManagementDAOException;
 
     /**
      * Get all the certificates in a paginated manner.
+     *
      * @param request Request mentioning pagination details such as length and stating index.
      * @return Pagination result with data and the count of results.
      * @throws CertificateManagementDAOException
+     *
      */
     PaginationResult getAllCertificates(PaginationRequest request) throws CertificateManagementDAOException;
 
     /**
      * Get all the certificates.
+     *
      * @return List of certificates
      * @throws CertificateManagementDAOException
+     *
      */
     public List<CertificateResponse> getAllCertificates() throws CertificateManagementDAOException;
 
     /**
      * Delete a certificate identified by a serial number()
+     *
      * @param serialNumber serial number
      * @return whether the certificate was removed or not.
      */
     boolean removeCertificate(String serialNumber) throws CertificateManagementDAOException;
 
     public List<CertificateResponse> searchCertificate(String serialNumber) throws CertificateManagementDAOException;
+
 }

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/dao/CertificateManagementDAOFactory.java

@@ -50,7 +50,7 @@ public class CertificateManagementDAOFactory {
         try {
             databaseEngine = dataSource.getConnection().getMetaData().getDatabaseProductName();
         } catch (SQLException e) {
-            log.error("Error occurred while retrieving config.datasource connection", e);
+            log.error(  "Error occurred while retrieving config.datasource connection", e);
         }
     }
 
@@ -59,7 +59,7 @@ public class CertificateManagementDAOFactory {
         try {
             databaseEngine = dataSource.getConnection().getMetaData().getDatabaseProductName();
         } catch (SQLException e) {
-            log.error("Error occurred while retrieving config.datasource connection", e);
+            log.error("Error occurred while retrieving a datasource connection", e);
         }
     }
 
@@ -72,11 +72,22 @@ public class CertificateManagementDAOFactory {
         }
         try {
             conn = dataSource.getConnection();
+        } catch (SQLException e) {
+            throw new TransactionManagementException("Error occurred while retrieving a data source connection", e);
+        }
+
+        try {
             conn.setAutoCommit(false);
-            currentConnection.set(conn);
         } catch (SQLException e) {
-            throw new TransactionManagementException("Error occurred while retrieving config.datasource connection", e);
+            try {
+                conn.close();
+            } catch (SQLException e1) {
+                log.warn("Error occurred while closing the borrowed connection. " +
+                        "Transaction has ended pre-maturely", e1);
             }
+            throw new TransactionManagementException("Error occurred while setting auto-commit to false", e);
+        }
+        currentConnection.set(conn);
     }
 
     public static void openConnection() throws SQLException {
@@ -111,6 +122,8 @@ public class CertificateManagementDAOFactory {
             conn.commit();
         } catch (SQLException e) {
             log.error("Error occurred while committing the transaction", e);
+        } finally {
+            closeConnection();
         }
     }
 
@@ -125,6 +138,8 @@ public class CertificateManagementDAOFactory {
             conn.rollback();
         } catch (SQLException e) {
             log.warn("Error occurred while roll-backing the transaction", e);
+        } finally {
+            closeConnection();
         }
     }
 
@@ -138,7 +153,7 @@ public class CertificateManagementDAOFactory {
         try {
             conn.close();
         } catch (SQLException e) {
-            log.warn("Error occurred while close the connection");
+            log.warn("Error occurred while close the connection", e);
         }
         currentConnection.remove();
     }

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/CertificateGenerator.java

@@ -674,10 +674,7 @@ public class CertificateGenerator {
         } catch (TransactionManagementException e) {
             String errorMsg = "Error occurred when saving the generated certificate";
             log.error(errorMsg, e);
-            CertificateManagementDAOFactory.rollbackTransaction();
             throw new KeystoreException(errorMsg, e);
-        } finally {
-            CertificateManagementDAOFactory.closeConnection();
         }
     }
 
@@ -738,9 +735,8 @@ public class CertificateGenerator {
         } catch (IOException e) {
             throw new KeystoreException("CSR cannot be recovered.", e);
         }
-        X509Certificate signedCertificate = generateCertificateFromCSR(privateKeyCA, certificationRequest,
+        return generateCertificateFromCSR(privateKeyCA, certificationRequest,
                 certCA.getIssuerX500Principal().getName());
-        return signedCertificate;
     }
 
     public static void extractCertificateDetails(byte[] certificateBytes, CertificateResponse certificateResponse)

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/impl/KeyStoreReader.java

@@ -19,6 +19,7 @@ package org.wso2.carbon.certificate.mgt.core.impl;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.wso2.carbon.certificate.mgt.core.dao.CertificateDAO;
 import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOException;
 import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOFactory;
 import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
@@ -41,17 +42,21 @@ public class KeyStoreReader {
 
     private static final Log log = LogFactory.getLog(KeyStoreReader.class);
 
-    private KeyStore loadKeyStore(String configEntryKeyStoreType, String configEntryKeyStorePath,
+    private CertificateDAO certDao;
-                                  String configEntryKeyStorePassword) throws KeystoreException {
 
-        InputStream inputStream = null;
+    public KeyStoreReader() {
-        KeyStore keystore;
+        this.certDao = CertificateManagementDAOFactory.getCertificateDAO();
+    }
 
+    private KeyStore loadKeyStore(
+            String configEntryKeyStoreType, String configEntryKeyStorePath,
+            String configEntryKeyStorePassword) throws KeystoreException {
+        InputStream is = null;
+        KeyStore keystore;
         try {
             keystore = KeyStore.getInstance(ConfigurationUtil.getConfigEntry(configEntryKeyStoreType));
-            inputStream = new FileInputStream(ConfigurationUtil.getConfigEntry(configEntryKeyStorePath));
+            is = new FileInputStream(ConfigurationUtil.getConfigEntry(configEntryKeyStorePath));
-            keystore.load(inputStream, ConfigurationUtil.getConfigEntry(configEntryKeyStorePassword).toCharArray());
+            keystore.load(is, ConfigurationUtil.getConfigEntry(configEntryKeyStorePassword).toCharArray());
-
         } catch (KeyStoreException e) {
             String errorMsg = "KeyStore issue occurred when loading KeyStore";
             log.error(errorMsg, e);
@@ -74,8 +79,8 @@ public class KeyStoreReader {
             throw new KeystoreException(errorMsg, e);
         } finally {
             try {
-                if (inputStream != null) {
+                if (is != null) {
-                    inputStream.close();
+                    is.close();
                 }
             } catch (IOException e) {
                 log.error("Error closing KeyStore input stream", e);
@@ -87,15 +92,11 @@ public class KeyStoreReader {
 
     private synchronized void saveKeyStore(KeyStore keyStore, String configEntryKeyStorePath,
                                            String configEntryKeyStorePassword) throws KeystoreException {
-
+        FileOutputStream os = null;
-        FileOutputStream outputStream = null;
-
         try {
-            outputStream = new FileOutputStream(
+            os = new FileOutputStream(
                     ConfigurationUtil.getConfigEntry(configEntryKeyStorePath));
-            keyStore.store(outputStream, ConfigurationUtil.getConfigEntry(configEntryKeyStorePassword).toCharArray());
+            keyStore.store(os, ConfigurationUtil.getConfigEntry(configEntryKeyStorePassword).toCharArray());
-            outputStream.close();
-
         } catch (KeyStoreException e) {
             String errorMsg = "KeyStore issue occurred when loading KeyStore";
             log.error(errorMsg, e);
@@ -118,8 +119,8 @@ public class KeyStoreReader {
             throw new KeystoreException(errorMsg, e);
         } finally {
             try {
-                if (outputStream != null) {
+                if (os != null) {
-                    outputStream.close();
+                    os.close();
                 }
             } catch (IOException e) {
                 log.error("Error closing KeyStore output stream", e);
@@ -139,10 +140,8 @@ public class KeyStoreReader {
     }
 
     public Certificate getCACertificate() throws KeystoreException {
-
         KeyStore keystore = loadCertificateKeyStore();
         Certificate caCertificate;
-
         try {
             caCertificate = keystore.getCertificate(ConfigurationUtil.getConfigEntry(ConfigurationUtil.CA_CERT_ALIAS));
         } catch (KeyStoreException e) {
@@ -188,7 +187,6 @@ public class KeyStoreReader {
     }
 
     public Certificate getRACertificate() throws KeystoreException {
-
         KeyStore keystore = loadCertificateKeyStore();
         Certificate raCertificate;
         try {
@@ -207,13 +205,11 @@ public class KeyStoreReader {
     }
 
     public Certificate getCertificateByAlias(String alias) throws KeystoreException {
-
         Certificate raCertificate = null;
         try {
             CertificateManagementDAOFactory.openConnection();
-            CertificateResponse certificateResponse = CertificateManagementDAOFactory.getCertificateDAO().
+            CertificateResponse certificateResponse = certDao.retrieveCertificate(alias);
-                    retrieveCertificate(alias);
+            if (certificateResponse != null) {
-            if(certificateResponse != null) {
                 raCertificate = (Certificate) Serializer.deserialize(certificateResponse.getCertificate());
             }
         } catch (CertificateManagementDAOException e) {
@@ -221,7 +217,7 @@ public class KeyStoreReader {
             log.error(errorMsg, e);
             throw new KeystoreException(errorMsg, e);
         } catch (ClassNotFoundException | IOException e) {
-            String errorMsg = "Error when deserializing saved certificate.";
+            String errorMsg = "Error when de-serializing saved certificate.";
             log.error(errorMsg, e);
             throw new KeystoreException(errorMsg, e);
         } catch (SQLException e) {
@@ -234,8 +230,7 @@ public class KeyStoreReader {
         return raCertificate;
     }
 
-    PrivateKey getRAPrivateKey() throws KeystoreException {
+    public PrivateKey getRAPrivateKey() throws KeystoreException {
-
         KeyStore keystore = loadCertificateKeyStore();
         PrivateKey raPrivateKey;
         try {
@@ -264,13 +259,11 @@ public class KeyStoreReader {
     }
 
     public CertificateResponse getCertificateBySerial(String serialNumber) throws KeystoreException {
-
         CertificateResponse certificateResponse = null;
         try {
             CertificateManagementDAOFactory.openConnection();
-            certificateResponse = CertificateManagementDAOFactory.getCertificateDAO().
+            certificateResponse = certDao.retrieveCertificate(serialNumber);
-                    retrieveCertificate(serialNumber);
+            if (certificateResponse != null && certificateResponse.getCertificate() != null) {
-            if(certificateResponse != null && certificateResponse.getCertificate() != null) {
                 Certificate certificate = (Certificate) Serializer.deserialize(certificateResponse.getCertificate());
                 if (certificate instanceof X509Certificate) {
                     X509Certificate x509cert = (X509Certificate) certificate;
@@ -278,7 +271,6 @@ public class KeyStoreReader {
                     certificateResponse.setCommonName(commonName);
                 }
             }
-
         } catch (CertificateManagementDAOException e) {
             String errorMsg = "Error when retrieving certificate from the the database for the serial number: " +
                     serialNumber;
@@ -289,7 +281,7 @@ public class KeyStoreReader {
             log.error(errorMsg, e);
             throw new KeystoreException(errorMsg, e);
         } catch (ClassNotFoundException | IOException e) {
-            String errorMsg = "Error when deserializing saved certificate.";
+            String errorMsg = "Error when de-serializing saved certificate.";
             log.error(errorMsg, e);
             throw new KeystoreException(errorMsg, e);
         } finally {

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementService.java

@@ -18,7 +18,7 @@
 package org.wso2.carbon.certificate.mgt.core.service;
 
 import org.bouncycastle.pkcs.PKCS10CertificationRequest;
-import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOException;
+import org.wso2.carbon.certificate.mgt.core.exception.CertificateManagementException;
 import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
 import org.wso2.carbon.certificate.mgt.core.dto.SCEPResponse;
 import org.wso2.carbon.certificate.mgt.core.exception.KeystoreException;
@@ -47,8 +47,8 @@ public interface CertificateManagementService {
 
     byte[] getPKIMessageSCEP(InputStream inputStream) throws KeystoreException;
 
-    X509Certificate generateCertificateFromCSR(PrivateKey privateKey, PKCS10CertificationRequest request,
+    X509Certificate generateCertificateFromCSR(
-                                               String issueSubject) throws KeystoreException;
+            PrivateKey privateKey, PKCS10CertificationRequest request, String issueSubject) throws KeystoreException;
 
     Certificate getCertificateByAlias(String alias) throws KeystoreException;
 
@@ -71,13 +71,14 @@ public interface CertificateManagementService {
 
     public X509Certificate pemToX509Certificate(String pem) throws KeystoreException;
 
-    public CertificateResponse retrieveCertificate(String serialNumber) throws CertificateManagementDAOException;
+    public CertificateResponse retrieveCertificate(String serialNumber) throws CertificateManagementException;
 
-    public PaginationResult getAllCertificates(PaginationRequest request) throws CertificateManagementDAOException;
+    public PaginationResult getAllCertificates(PaginationRequest request) throws CertificateManagementException;
 
-    boolean removeCertificate(String serialNumber) throws CertificateManagementDAOException;
+    boolean removeCertificate(String serialNumber) throws CertificateManagementException;
 
-    public List<CertificateResponse> getCertificates() throws CertificateManagementDAOException;
+    public List<CertificateResponse> getCertificates() throws CertificateManagementException;
+
+    public List<CertificateResponse> searchCertificates(String serialNumber) throws CertificateManagementException;
 
-    public List<CertificateResponse> searchCertificates(String serialNumber) throws CertificateManagementDAOException;
 }

components/certificate-mgt/org.wso2.carbon.certificate.mgt.core/src/main/java/org/wso2/carbon/certificate/mgt/core/service/CertificateManagementServiceImpl.java

@@ -25,6 +25,7 @@ import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOExceptio
 import org.wso2.carbon.certificate.mgt.core.dao.CertificateManagementDAOFactory;
 import org.wso2.carbon.certificate.mgt.core.dto.CertificateResponse;
 import org.wso2.carbon.certificate.mgt.core.dto.SCEPResponse;
+import org.wso2.carbon.certificate.mgt.core.exception.CertificateManagementException;
 import org.wso2.carbon.certificate.mgt.core.exception.KeystoreException;
 import org.wso2.carbon.certificate.mgt.core.impl.CertificateGenerator;
 import org.wso2.carbon.certificate.mgt.core.impl.KeyStoreReader;
@@ -51,7 +52,6 @@ public class CertificateManagementServiceImpl implements CertificateManagementSe
     }
 
     public static CertificateManagementServiceImpl getInstance() {
-
         if (certificateManagementServiceImpl == null) {
             certificateManagementServiceImpl = new CertificateManagementServiceImpl();
             keyStoreReader = new KeyStoreReader();
@@ -106,7 +106,8 @@ public class CertificateManagementServiceImpl implements CertificateManagementSe
         return certificateGenerator.verifyPEMSignature(requestCertificate);
     }
 
-    @Override public CertificateResponse verifySubjectDN(String requestDN) throws KeystoreException {
+    @Override
+    public CertificateResponse verifySubjectDN(String requestDN) throws KeystoreException {
         return certificateGenerator.verifyCertificateDN(requestDN);
     }
 
@@ -135,39 +136,47 @@ public class CertificateManagementServiceImpl implements CertificateManagementSe
         return certificateGenerator.pemToX509Certificate(pem);
     }
 
-    public CertificateResponse retrieveCertificate(String serialNumber)
+    public CertificateResponse retrieveCertificate(String serialNumber) throws CertificateManagementException {
-            throws CertificateManagementDAOException {
         CertificateDAO certificateDAO;
         try {
             CertificateManagementDAOFactory.openConnection();
             certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
             return certificateDAO.retrieveCertificate(serialNumber);
         } catch (SQLException e) {
-            String errorMsg = "Error when opening connection";
+            String msg = "Error occurred while opening a connection to the underlying data source";
-            log.error(errorMsg, e);
+            log.error(msg, e);
-            throw new CertificateManagementDAOException(errorMsg, e);
+            throw new CertificateManagementException(msg, e);
+        } catch (CertificateManagementDAOException e) {
+            String msg = "Error occurred while looking up for the certificate carrying the serial number '" +
+                    serialNumber + "' in the underlying certificate repository";
+            log.error(msg, e);
+            throw new CertificateManagementException(msg, e);
         } finally {
             CertificateManagementDAOFactory.closeConnection();
         }
     }
 
-    public PaginationResult getAllCertificates(PaginationRequest request)
+    public PaginationResult getAllCertificates(PaginationRequest request) throws CertificateManagementException {
-            throws CertificateManagementDAOException {
         try {
             CertificateManagementDAOFactory.openConnection();
             CertificateDAO certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
             return certificateDAO.getAllCertificates(request);
         } catch (SQLException e) {
-            String errorMsg = "Error when opening connection";
+            String msg = "Error occurred while opening a connection to the underlying data source";
-            log.error(errorMsg, e);
+            log.error(msg, e);
-            throw new CertificateManagementDAOException(errorMsg, e);
+            throw new CertificateManagementException(msg, e);
+        } catch (CertificateManagementDAOException e) {
+            String msg = "Error occurred while looking up for the list of certificates managed in the underlying " +
+                    "certificate repository";
+            log.error(msg, e);
+            throw new CertificateManagementException(msg, e);
         } finally {
             CertificateManagementDAOFactory.closeConnection();
         }
     }
 
     @Override
-    public boolean removeCertificate(String serialNumber) throws CertificateManagementDAOException {
+    public boolean removeCertificate(String serialNumber) throws CertificateManagementException {
         try {
             CertificateManagementDAOFactory.beginTransaction();
             CertificateDAO certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
@@ -175,38 +184,53 @@ public class CertificateManagementServiceImpl implements CertificateManagementSe
             CertificateManagementDAOFactory.commitTransaction();
             return status;
         } catch (TransactionManagementException e) {
-            String errorMsg = "Error when deleting";
+            String msg = "Error occurred while removing certificate carrying serial number '" + serialNumber + "'";
-            log.error(errorMsg, e);
+            log.error(msg, e);
-            throw new CertificateManagementDAOException(errorMsg, e);
+            throw new CertificateManagementException(msg, e);
-        } finally {
+        } catch (CertificateManagementDAOException e) {
-            CertificateManagementDAOFactory.closeConnection();
+            CertificateManagementDAOFactory.rollbackTransaction();
+            String msg = "Error occurred while removing the certificate carrying serial number '" + serialNumber +
+                    "' from the certificate repository";
+            log.error(msg, e);
+            throw new CertificateManagementException(msg, e);
         }
     }
 
     @Override
-    public List<CertificateResponse> getCertificates() throws CertificateManagementDAOException {
+    public List<CertificateResponse> getCertificates() throws CertificateManagementException {
         try {
             CertificateManagementDAOFactory.openConnection();
             CertificateDAO certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
             return certificateDAO.getAllCertificates();
         } catch (SQLException e) {
-            String errorMsg = "Error when opening connection";
+            String msg = "Error occurred while opening a connection to the underlying data source";
-            log.error(errorMsg, e);
+            log.error(msg, e);
-            throw new CertificateManagementDAOException(errorMsg, e);
+            throw new CertificateManagementException(msg, e);
+        } catch (CertificateManagementDAOException e) {
+            String msg = "Error occurred while looking up for the list of certificates managed in the " +
+                    "underlying certificate repository";
+            log.error(msg, e);
+            throw new CertificateManagementException(msg, e);
         } finally {
             CertificateManagementDAOFactory.closeConnection();
         }
     }
 
-    @Override public List<CertificateResponse> searchCertificates(String serialNumber) throws CertificateManagementDAOException {
+    @Override
+    public List<CertificateResponse> searchCertificates(String serialNumber) throws CertificateManagementException {
         try {
             CertificateManagementDAOFactory.openConnection();
             CertificateDAO certificateDAO = CertificateManagementDAOFactory.getCertificateDAO();
             return certificateDAO.searchCertificate(serialNumber);
         } catch (SQLException e) {
-            String errorMsg = "Error when opening connection";
+            String msg = "Error occurred while opening a connection to the underlying data source";
-            log.error(errorMsg, e);
+            log.error(msg, e);
-            throw new CertificateManagementDAOException(errorMsg, e);
+            throw new CertificateManagementException(msg, e);
+        } catch (CertificateManagementDAOException e) {
+            String msg = "Error occurred while searching for the list of certificates carrying the serial number '" +
+                    serialNumber + "' in the underlying certificate repository";
+            log.error(msg, e);
+            throw new CertificateManagementException(msg, e);
         } finally {
             CertificateManagementDAOFactory.closeConnection();
         }

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/operation/mgt/OperationManagerImpl.java

@@ -209,14 +209,27 @@ public class OperationManagerImpl implements OperationManager {
                 throw new UnauthorizedDeviceAccessException("User '" + getUser() + "' is not authorized to " +
                         "fetch operations on device '" + deviceId.getId() + "'");
             }
-            try {
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving metadata of '" +
+                    deviceId.getType() + "' device carrying the identifier '" +
+                    deviceId.getId() + "'");
+        } catch (SQLException e) {
+            throw new OperationManagementException(
+                    "Error occurred while opening a connection to the data source", e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
+
+        try {
             if (enrolmentId < 0) {
                 return null;
             }
@@ -233,20 +246,12 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the list of " +
                     "operations assigned for '" + deviceId.getType() +
                     "' device '" + deviceId.getId() + "'", e);
-            } catch (DeviceManagementDAOException e) {
-                throw new OperationManagementException("Error occurred while retrieving metadata of '" +
-                        deviceId.getType() + "' device carrying the identifier '" +
-                        deviceId.getId() + "'");
         } catch (SQLException e) {
             throw new OperationManagementException(
                     "Error occurred while opening a connection to the data source", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
-                    this.getUser(), e);
-        }
         return operations;
     }
 
@@ -259,16 +264,31 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.error("User : " + getUser() + " is not authorized to fetch operations on device : " +
+                        deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (SQLException e) {
+            throw new OperationManagementException(
+                    "Error occurred while opening a connection to the data source", e);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving metadata of '" +
+                    deviceId.getType() + "' device carrying the identifier '" +
+                    deviceId.getId() + "'");
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
 
+        try {
             OperationManagementDAOFactory.openConnection();
             if (enrolmentId < 0) {
                 throw new OperationManagementException("Device not found for given device " +
@@ -290,23 +310,12 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the list of " +
                     "operations assigned for '" + deviceId.getType() +
                     "' device '" + deviceId.getId() + "'", e);
-                } catch (DeviceManagementDAOException e) {
-                    throw new OperationManagementException("Error occurred while retrieving metadata of '" +
-                            deviceId.getType() + "' device carrying the identifier '" +
-                            deviceId.getId() + "'");
         } catch (SQLException e) {
             throw new OperationManagementException(
                     "Error occurred while opening a connection to the data source", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
-                log.info("User : " + getUser() + " is not authorized to fetch operations on device : " + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
-                    this.getUser(), e);
-        }
 
         return paginationResult;
     }
@@ -323,15 +332,31 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.error("User : " + getUser() + " is not authorized to fetch operations on device : "
+                        + deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (SQLException e) {
+            throw new OperationManagementException(
+                    "Error occurred while opening a connection to the data source", e);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving the device " +
+                    "for device Identifier type -'" + deviceId.getType() +
+                    "' and device Id '" + deviceId.getId() + "'", e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
+
+        try {
             OperationManagementDAOFactory.openConnection();
             if (enrolmentId < 0) {
                 throw new OperationManagementException("Device not found for the given device Identifier:" +
@@ -356,24 +381,12 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the list of " +
                     "pending operations assigned for '" + deviceId.getType() +
                     "' device '" + deviceId.getId() + "'", e);
-                } catch (DeviceManagementDAOException e) {
-                    throw new OperationManagementException("Error occurred while retrieving the device " +
-                            "for device Identifier type -'" + deviceId.getType() +
-                            "' and device Id '" + deviceId.getId() + "'", e);
         } catch (SQLException e) {
             throw new OperationManagementException(
                     "Error occurred while opening a connection to the data source", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
-                log.info("User : " + getUser() + " is not authorized to fetch operations on device : "
-                        + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
-                    this.getUser(), e);
-        }
         return operations;
     }
 
@@ -387,15 +400,31 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.error("User : " + getUser() + " is not authorized to fetch operations on device : "
+                        + deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving the device " +
+                    "for device Identifier type -'" + deviceId.getType() +
+                    "' and device Id '" + deviceId.getId(), e);
+        } catch (SQLException e) {
+            throw new OperationManagementException(
+                    "Error occurred while opening a connection to the data source", e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
+
+        try {
             OperationManagementDAOFactory.openConnection();
             if (enrolmentId < 0) {
                 throw new OperationManagementException("Device not found for given device " +
@@ -426,24 +455,12 @@ public class OperationManagerImpl implements OperationManager {
             }
         } catch (OperationManagementDAOException e) {
             throw new OperationManagementException("Error occurred while retrieving next pending operation", e);
-                } catch (DeviceManagementDAOException e) {
-                    throw new OperationManagementException("Error occurred while retrieving the device " +
-                            "for device Identifier type -'" + deviceId.getType() +
-                            "' and device Id '" + deviceId.getId(), e);
         } catch (SQLException e) {
             throw new OperationManagementException(
                     "Error occurred while opening a connection to the data source", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
-                log.info("User : " + getUser() + " is not authorized to fetch operations on device : "
-                        + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user : " +
-                    this.getUser(), e);
-        }
         return operation;
     }
 
@@ -457,8 +474,15 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.error("User : " + getUser() + " is not authorized to update operations on device : "
+                        + deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
@@ -466,9 +490,16 @@ public class OperationManagerImpl implements OperationManager {
         } catch (SQLException e) {
             throw new OperationManagementException("Error occurred while opening a connection to the" +
                     " data source", e);
+        } catch (DeviceManagementDAOException e) {
+            OperationManagementDAOFactory.rollbackTransaction();
+            throw new OperationManagementException(
+                    "Error occurred while fetching the device for device identifier: " + deviceId.getId() +
+                            "type:" + deviceId.getType(), e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
+
+        try {
             OperationManagementDAOFactory.beginTransaction();
             boolean isUpdated = false;
             if (operation.getStatus() != null) {
@@ -485,24 +516,11 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException(
                     "Error occurred while updating the operation: " + operationId + " status:" +
                             operation.getStatus(), e);
-                } catch (DeviceManagementDAOException e) {
-                    OperationManagementDAOFactory.rollbackTransaction();
-                    throw new OperationManagementException(
-                            "Error occurred while fetching the device for device identifier: " + deviceId.getId() +
-                                    "type:" + deviceId.getType(), e);
         } catch (TransactionManagementException e) {
             throw new OperationManagementException("Error occurred while initiating a transaction", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
-                log.info("User : " + getUser() + " is not authorized to update operations on device : "
-                        + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
-                    this.getUser(), e);
-        }
     }
 
     @Override
@@ -538,16 +556,31 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.error("User : " + getUser() + " is not authorized to fetch operations on device : "
+                        + deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving the device " +
+                    "for device Identifier type -'" + deviceId.getType() +
+                    "' and device Id '" + deviceId.getId() + "'", e);
+        } catch (SQLException e) {
+            throw new OperationManagementException("Error occurred while opening connection to the data source",
+                    e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
 
+        try {
             OperationManagementDAOFactory.openConnection();
             if (enrolmentId < 0) {
                 throw new OperationManagementException("Device not found for given device identifier: " +
@@ -582,24 +615,13 @@ public class OperationManagerImpl implements OperationManager {
             throw new OperationManagementException("Error occurred while retrieving the list of " +
                     "operations assigned for '" + deviceId.getType() +
                     "' device '" + deviceId.getId() + "'", e);
-                } catch (DeviceManagementDAOException e) {
-                    throw new OperationManagementException("Error occurred while retrieving the device " +
-                            "for device Identifier type -'" + deviceId.getType() +
-                            "' and device Id '" + deviceId.getId() + "'", e);
         } catch (SQLException e) {
             throw new OperationManagementException("Error occurred while opening connection to the data source",
                     e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
+
-                log.info("User : " + getUser() + " is not authorized to fetch operations on device : "
-                        + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
-                    this.getUser(), e);
-        }
         return operation;
     }
 
@@ -612,15 +634,31 @@ public class OperationManagerImpl implements OperationManager {
         try {
             boolean isUserAuthorized = DeviceManagementDataHolder.getInstance().getDeviceAccessAuthorizationService().
                     isUserAuthorized(deviceId, DeviceGroupConstants.Permissions.DEFAULT_OPERATOR_PERMISSIONS);
-            if (isUserAuthorized) {
+            if (!isUserAuthorized) {
-                try {
+                log.info("User : " + getUser() + " is not authorized to fetch operations on device : "
+                        + deviceId.getId());
+            }
+        } catch (DeviceAccessAuthorizationException e) {
+            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
+                    this.getUser(), e);
+        }
+
         try {
             DeviceManagementDAOFactory.openConnection();
             int tenantId = CarbonContext.getThreadLocalCarbonContext().getTenantId();
             enrolmentId = deviceDAO.getEnrolmentByStatus(deviceId, EnrolmentInfo.Status.ACTIVE, tenantId);
+        } catch (DeviceManagementDAOException e) {
+            throw new OperationManagementException("Error occurred while retrieving the device " +
+                    "for device Identifier type -'" + deviceId.getType() +
+                    "' and device Id '" + deviceId.getId(), e);
+        } catch (SQLException e) {
+            throw new OperationManagementException(
+                    "Error occurred while opening a connection to the data source", e);
         } finally {
             DeviceManagementDAOFactory.closeConnection();
         }
+
+        try {
             OperationManagementDAOFactory.openConnection();
 
             if (enrolmentId < 0) {
@@ -651,24 +689,12 @@ public class OperationManagerImpl implements OperationManager {
                     "operations assigned for '" + deviceId.getType() +
                     "' device '" +
                     deviceId.getId() + "' and status:" + status.toString(), e);
-                } catch (DeviceManagementDAOException e) {
-                    throw new OperationManagementException("Error occurred while retrieving the device " +
-                            "for device Identifier type -'" + deviceId.getType() +
-                            "' and device Id '" + deviceId.getId(), e);
         } catch (SQLException e) {
             throw new OperationManagementException(
                     "Error occurred while opening a connection to the data source", e);
         } finally {
             OperationManagementDAOFactory.closeConnection();
         }
-            } else {
-                log.info("User : " + getUser() + " is not authorized to fetch operations on device : "
-                        + deviceId.getId());
-            }
-        } catch (DeviceAccessAuthorizationException e) {
-            throw new OperationManagementException("Error occurred while authorizing access to the devices for user :" +
-                    this.getUser(), e);
-        }
         return operations;
     }
 
@@ -809,7 +835,8 @@ public class OperationManagerImpl implements OperationManager {
     }
 
     @Override
-    public List<Activity> getActivitiesUpdatedAfter(long timestamp, int limit, int offset) throws OperationManagementException {
+    public List<Activity> getActivitiesUpdatedAfter(long timestamp, int limit,
+                                                    int offset) throws OperationManagementException {
         try {
             OperationManagementDAOFactory.openConnection();
             return operationDAO.getActivitiesUpdatedAfter(timestamp, limit, offset);

components/device-mgt/org.wso2.carbon.device.mgt.core/src/test/java/org/wso2/carbon/device/mgt/core/Search/util/Utils.java

@@ -19,7 +19,6 @@
 
 package org.wso2.carbon.device.mgt.core.search.util;
 
-import org.wso2.carbon.device.mgt.common.Device;
 import org.wso2.carbon.device.mgt.common.DeviceIdentifier;
 import org.wso2.carbon.device.mgt.common.device.details.DeviceInfo;
 import org.wso2.carbon.device.mgt.common.device.details.DeviceLocation;