uk.ac.ox.it.ords.security.services.impl.ServerConfigurationServiceImpl.java Source code

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Here is the source code for uk.ac.ox.it.ords.security.services.impl.ServerConfigurationServiceImpl.java

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/*
 * Copyright 2015 University of Oxford
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package uk.ac.ox.it.ords.security.services.impl;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.configuration.XMLConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import uk.ac.ox.it.ords.security.configuration.MetaConfiguration;
import uk.ac.ox.it.ords.security.model.DatabaseServer;
import uk.ac.ox.it.ords.security.services.ServerConfigurationService;

/**
 * Default implementation of the database credentials interface that stores
 * credentials in a file on the server.
 */
public class ServerConfigurationServiceImpl implements ServerConfigurationService {

    public static Logger log = LoggerFactory.getLogger(ServerConfigurationServiceImpl.class);

    /**
     * The default configuration location; this can be overridden in config.xml to point
     * to another file.
     */
    public static final String DEFAULT_SERVER_CONFIG_LOCATION = "databaseservers.xml";

    /**
     * Singleton instance
     */
    private static ServerConfigurationServiceImpl instance;

    /**
     * Private constructor for singleton
     */
    private ServerConfigurationServiceImpl() {
        try {
            load();
        } catch (Exception e) {
            log.error("Couldn't load database server credentials");
        }
    }

    /**
     * Get the service instance
     * @return the service instance
     */
    public static ServerConfigurationServiceImpl getInstance() {
        if (instance == null)
            instance = new ServerConfigurationServiceImpl();

        return instance;
    }

    /**
     * The servers defined in the configuration file
     */
    private List<DatabaseServer> servers;

    /**
     * The server for the internal metadata
     */
    private DatabaseServer metadataServer;

    /**
     * Loads the configuration file
     * @throws Exception if there is a problem loading the file
     */
    protected void load() throws Exception {

        String serverConfigurationLocation = DEFAULT_SERVER_CONFIG_LOCATION;

        //
        // Check if there is a different load location from the default
        //
        try {
            serverConfigurationLocation = MetaConfiguration.getConfiguration()
                    .getString("ords.server.configuration");
            if (serverConfigurationLocation == null) {
                log.debug("No server configuration location set; using defaults");
                serverConfigurationLocation = DEFAULT_SERVER_CONFIG_LOCATION;
            }
        } catch (Exception e) {
            log.debug("No server configuration location set; using defaults");
            serverConfigurationLocation = DEFAULT_SERVER_CONFIG_LOCATION;
        }

        //
        // Load the Server Configuration file
        //
        XMLConfiguration xmlServerConfiguration = new XMLConfiguration();
        try {
            xmlServerConfiguration.setFileName(serverConfigurationLocation);
            xmlServerConfiguration.load();
        } catch (Exception e1) {
            log.error("Cannot read server configuration at " + serverConfigurationLocation);
            throw new Exception("Cannot read server configuration");
        }

        //
        // Read the server list
        //
        int serverArray = xmlServerConfiguration.getStringArray("server[@host]").length;

        servers = new ArrayList<DatabaseServer>();

        for (int i = 0; i < serverArray; i++) {
            DatabaseServer databaseServer = new DatabaseServer();

            databaseServer.setHost(xmlServerConfiguration.getString("server(" + i + ")[@host]"));
            databaseServer.setPort(xmlServerConfiguration.getInt("server(" + i + ")[@port]"));
            databaseServer.setUsername(xmlServerConfiguration.getString("server(" + i + ")[@username]"));
            databaseServer.setPassword(xmlServerConfiguration.getString("server(" + i + ")[@password]"));
            databaseServer.setMasterDatabaseName(xmlServerConfiguration.getString("server(" + i + ")[@database]"));

            servers.add(databaseServer);
        }

        metadataServer = new DatabaseServer();
        metadataServer.setHost(xmlServerConfiguration.getString("metadata(0)[@host]"));
        metadataServer.setPort(xmlServerConfiguration.getInt("metadata(0)[@port]"));
        metadataServer.setUsername(xmlServerConfiguration.getString("metadata(0)[@username]"));
        metadataServer.setPassword(xmlServerConfiguration.getString("metadata(0)[@password]"));
        metadataServer.setMasterDatabaseName(xmlServerConfiguration.getString("metadata(0)[@database]"));

    }

    @Override
    public DatabaseServer getDatabaseServer() throws Exception {
        return servers.get(0);
    }

    @Override
    public List<DatabaseServer> getAllDatabaseServers() throws Exception {
        return servers;
    }

    @Override
    public DatabaseServer getDatabaseServer(String host) throws Exception {
        for (DatabaseServer databaseServer : servers) {
            if (databaseServer.getHost().equalsIgnoreCase(host)) {
                return databaseServer;
            }
        }
        return null;
    }

    @Override
    public DatabaseServer getOrdsDatabaseServer() throws Exception {
        return metadataServer;
    }

}