New working version after Victoria trip - FileRecord in place of HashMap and DBConnectionMng usage

/**_____________________________________________________________________________

 *

 *                                 OATS - INAF

 *  Osservatorio Astronomico di Tireste - Istituto Nazionale di Astrofisica

 *  Astronomical Observatory of Trieste - National Institute for Astrophysics

 * ____________________________________________________________________________

 *

 * Copyright (C) 20016  Istituto Nazionale di Astrofisica

 * 

 * 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., 

 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 * _____________________________________________________________________________

 **/

package it.inaf.oats.vospacebackend.implementation;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.SQLException;

import java.sql.ResultSet;

import org.apache.log4j.Logger;

import it.inaf.oats.vospacebackend.exceptions.ExceptionMessage;

import it.inaf.oats.vospacebackend.exceptions.VOSpaceBackendException;

/*

 * FileRecord myParams is used as input record

 * HashMap myResult is used as output record

 * @author bertocco

 */

public class VOSpaceBackendMetadata {

    /**

     * This class has two attributes:

     * <p>

     * Logger to perform logging operations

     * <p>

     * HashMap which will contain the metadata set identifying a stored/to store file

     * This hashmap fields will are:

     * boolean ifSuccessfull if db query is successful or not

     * String "original_file_name"

     * String "stored_file_name"

     * String "md5_checksum"

     * String "relative_path"

     */

    protected Logger log;

    protected FileRecord myResult; 

    /** 

     * Create the log and the HashMap that will be used to store the database

     * query result to return. The field "ifSuccessful" will contain a boolean 

     * value true if operation successfully executed and false if not.

     * Other fields will be added containing the query result set fields, 

     * depending on the executed query.

     */

    public VOSpaceBackendMetadata() {

        log = Logger.getLogger(VOSpaceBackendMetadata.class);  

        myResult = new FileRecord();

        myResult.setIfOperationSuccessful(false);

    }

    /**

     * 

     * @param fileName Original file name (provided by the client) of the file to store

     * @param stored_f_name name used to store the file in the file system

     * @param md5Checksum MD5 checksum of the file to store

     * @param relativePath relative path (after the root) of the file to store

     * @return boolean true if operation successful false if not

     * @throws VOSpaceBackendException

     */

    public FileRecord setFile(String stored_f_name, String md5Checksum, 

                         String relativePath) 

                                  throws VOSpaceBackendException, SQLException {

        String myOp = "SET";

        String myQuery = "INSERT INTO cadctest.StoredFiles " +

                "(stored_file_name, md5_checksum, relative_path)" +

                " VALUES (?, ?, ?);";

        FileRecord myParams = new FileRecord();

        myParams.setStoredfileName(stored_f_name);

        myParams.setMD5Checksum(md5Checksum);

        myParams.setRelativePath(relativePath);

        return excuteQuery(myOp, myQuery, myParams);

    }

    public FileRecord getFile(String orig_f_name) 

                                  throws VOSpaceBackendException, SQLException {

        String myOp = "GET";

        String myQuery = "SELECT * FROM cadctest.StoredFiles " +

                "WHERE original_file_name=?";

        // Da rifare: ricevo o il nodeid e con questo devo beccarmi il file

        // prima becco lo storage fname nella tabella node-storage e con quello

        // becco il file nella tabella storedFiles

        FileRecord myParams = new FileRecord();

        myParams.setStoredfileName(orig_f_name);

        return excuteQuery(myOp, myQuery, myParams);

    }

    public FileRecord getRequest(String nodeID) 

                                  throws VOSpaceBackendException, SQLException {

        String myOp = "GET_REQ";

        String myQuery = "SELECT * FROM cadctest.StoredFileAndNode " +

                "WHERE nodeID=?";

        // Da risistemare, non so neanche piu` se la uso ancora

        FileRecord myParams = new FileRecord();

        myParams.setNodeId(nodeID);

        return excuteQuery(myOp, myQuery, myParams);

    }

    public FileRecord setRequest(String stored_f_name, String nodeID) 

                                  throws VOSpaceBackendException, SQLException {

        String myOp = "SET_REQ";

        String myQuery = "INSERT INTO cadctest.StoredFileAndNode " +

                "(nodeID, storedFileID)" +

                " VALUES (?, ?);";

        log.debug("query : " + myQuery);

        log.debug("parameters: nodeID = " +  nodeID + " storedFileID = " + stored_f_name);

        FileRecord myParams = new FileRecord();

        log.debug("File record created. Its value is:");

        log.debug(myParams);

        myParams.setStoredfileName(stored_f_name);

        myParams.setNodeId(nodeID);

        log.debug("Going to execute query with FileRecord = " + myParams.toString());

        return excuteQuery(myOp, myQuery, myParams);

    }

    private FileRecord excuteQuery(String operation, String query, FileRecord fileToManage) 

                                                throws VOSpaceBackendException, SQLException {

        PreparedStatement preparedStatementInsert = null;

        Connection dbConnection = null;

        try {

	    dbConnection = DBConnectionMng.getDBConnection();

            log.debug("Database connection get");

        } catch (SQLException e) {

            log.fatal(e);

            ExceptionMessage exMsg = new ExceptionMessage();

            throw new VOSpaceBackendException(ExceptionMessage.getMessage("UNABLE_TO_GET_DB_CONNECTION"));

	}

	try {

	    dbConnection.setAutoCommit(false);

            log.debug("Autocommit set false");

	} catch (SQLException e) {

            log.fatal(e);

            ExceptionMessage exMsg = new ExceptionMessage();

            throw new VOSpaceBackendException(ExceptionMessage.getMessage("ERROR_DISABLING_DB_AUTOCOMMIT"));

	}

	// Starts JDBC Transaction

        PreparedStatement preparedQuery = null;

        // boolean query result (success or not)

        log.debug("Input file record: " + fileToManage.toString());

        boolean ifQuerySuccessful = false;

	try {

            //HashMap fileToManageFields = fileToManage.getFileRecord();

            ResultSet rs = null;   

            int rowCounter = 0;

            switch (operation) {

                case "SET":

                    log.debug("Going to prepare query for SET operation");

                    preparedQuery = dbConnection.prepareStatement(query);

                    preparedQuery.setString(1, fileToManage.getStoredfileName());

                    preparedQuery.setString(2, fileToManage.getMD5Checksum());

                    preparedQuery.setString(3, fileToManage.getRelativePath()); 

                    log.debug("Going to execute query");

                    preparedQuery.executeUpdate();

                    log.debug("Query executed");

                    dbConnection.commit();

                    log.debug("Query committed");

                    ifQuerySuccessful = true;

                    break;

                case "GET":

                    preparedQuery = dbConnection.prepareStatement(query);

                    preparedQuery.setString(1, (String)fileToManage.getNodeId());

                    rs = preparedQuery.executeQuery();

                    rowCounter = 0;

                    while (rs.next()) {

                        rowCounter = rowCounter +1;

                        myResult.setStoredfileName(rs.getString("stored_file_name"));

                        myResult.setMD5Checksum(rs.getString("md5_checksum"));                        

                        // Sistemare questa faccenda del nome file originale

                        // myResult.put("original_file_name", rs.getString("original_file_name"));

                        myResult.setRelativePath(rs.getString("relative_path"));

                    }

                    if (rowCounter == 0) {

                        log.debug("GET: query successfully executed. File not found"); 

                        ifQuerySuccessful = false;

                    } else {

                        log.debug("GET: query successfully executed. File found");

                        ifQuerySuccessful = true;

                    }

                    break;

                case "GET_REQ":

                    preparedQuery = dbConnection.prepareStatement(query);

                    preparedQuery.setString(1, fileToManage.getNodeId());

                    rs = preparedQuery.executeQuery();

                    rowCounter = 0;

                    while (rs.next()) {

                        rowCounter = rowCounter +1;

                        myResult.setStoredfileName(rs.getString("stored_file_name"));

                        myResult.setNodeId(rs.getString("nodeID"));

                    }

                    if (rowCounter == 0) {

                        log.debug("GET_REQ: query NOT executed. File metadata not found in backend");                      

                        ifQuerySuccessful = false;

                    } else {

                        log.debug("GET_REQ: query successfully executed. File found in the backend");

                        ifQuerySuccessful = true;

                    }

                    break;

                case "SET_REQ":                   

                    log.debug("Going to prepare query for SET operation");

                    preparedQuery = dbConnection.prepareStatement(query);

                    preparedQuery.setString(1, fileToManage.getNodeId());

                    preparedQuery.setString(2, fileToManage.getStoredfileName());

                    log.debug("Parameters : nodeID = " + fileToManage.getNodeId() + " StoredfileName = " +fileToManage.getStoredfileName());

                    log.debug("Going to execute query");

                    preparedQuery.executeUpdate();

                    log.debug("Query executed");

                    dbConnection.commit();

                    log.debug("Query committed"); 

                    ifQuerySuccessful = true;

                    break;                    

                default:

                    ifQuerySuccessful = false;

                    ExceptionMessage exMsg = new ExceptionMessage();

                    log.fatal(ExceptionMessage.getMessage("DB_OPERATION_NOT_RECOGNIZED"));

                    throw new VOSpaceBackendException(ExceptionMessage.getMessage("DB_OPERATION_NOT_RECOGNIZED"));                    

                }

            dbConnection.setAutoCommit(true);

            dbConnection.close();

        } catch (SQLException e) {

            log.error("SQLException exception executing SET file" + e.getMessage());

	    dbConnection.rollback();

	} finally {

            if (preparedQuery != null) {

		preparedQuery.close();

            }

            if (dbConnection != null) {

		dbConnection.close();

            }

	} 

        myResult.setIfOperationSuccessful(ifQuerySuccessful);

        log.debug("Returning " + operation + " result:\n" + myResult.toString());

        return myResult;

    }

}