de.fiz.ddb.aas.util.AasConfiguration.java Source code

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Here is the source code for de.fiz.ddb.aas.util.AasConfiguration.java

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package de.fiz.ddb.aas.util;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.ResourcePatternResolver;

/**
 * @author Michael Hoppe
 * 
 * Reads properties from aas.properties file and hold them.
 *
 */
public final class AasConfiguration {

    private static AasConfiguration instance;

    private final Properties properties;

    private static final Logger LOGGER = LoggerFactory.getLogger(AasConfiguration.class);

    private static final String PROPERTIES_FILENAME = "aas.properties";

    private static final String PROPERTIES_DEFAULT_FILENAME = "aas-default.properties";

    public static final String LDAP_BASE_DN = "ldap.base.dn";

    public static final String LDAP_USERS_OU = "ldap.users.ou";

    public static final String LDAP_ORGANIZATIONS_OU = "ldap.organizations.ou";

    public static final String LDAP_LICENSEDORGS_OU = "ldap.licensedOrgs.ou";

    public static final String LDAP_PERMISSIONS_OU = "ldap.permissions.ou";

    public static final String LDAP_PROVIDER_URL = "ldap.provider.url";

    public static final String LDAP_ROOT_DN = "ldap.root.dn";

    public static final String LDAP_ROOT_DN_PASSWORD = "ldap.root.dn.password";

    public static final String HTTP_PROXY_URL = "proxy.url";

    public static final String HTTP_PROXY_PORT = "proxy.port";

    public static final String HTTP_NONPROXY_HOSTS = "proxy.nonproxy.hosts";

    public static final String MAIL_HOST = "mail.host";

    public static final String MAIL_SENDER = "mail.sender";

    public static final String HASH_ALGORITHM = "hash.algorithm";

    static {
        try {
            instance = new AasConfiguration();
        } catch (final IOException e) {
            if (LOGGER.isWarnEnabled()) {
                LOGGER.warn("Problem while loading properties.");
            }
            if (LOGGER.isDebugEnabled()) {
                LOGGER.debug("Problem while loading properties.", e);
            }
        }
    }

    /**
     * Private Constructor, in order to prevent instantiation of this utility class. read the Properties and fill it in
     * properties attribute.
     * @throws de.escidoc.core.common.exceptions.system.SystemException
     */
    private AasConfiguration() throws IOException {
        this.properties = loadProperties();
    }

    /**
     * Returns Object.
     *
     * @return AasConfiguration self
     * @throws IOException Thrown if properties loading fails.
     */
    public static AasConfiguration getInstance() {
        return instance;
    }

    /**
     * Returns the property with the given name or null if property was not found.
     *
     * @param name The name of the Property.
     * @return Value of the given Property as String.
     */
    public String get(final String name) {
        return (String) properties.get(name);
    }

    /**
     * Returns the property with the given name or the second parameter as default value if property was not found.
     *
     * @param name         The name of the Property.
     * @param defaultValue The default vaule if property isn't given.
     * @return Value of the given Property as String.
     */
    public String get(final String name, final String defaultValue) {
        String prop = (String) properties.get(name);

        if (prop == null) {
            prop = defaultValue;
        }
        return prop;
    }

    /**
     * Loads the Properties from properties-file.
     *
     * @return The properties
     * @throws IOException If the loading of the properties fails.
     */
    private static Properties loadProperties() throws IOException {
        final Properties result = getProperties(PROPERTIES_DEFAULT_FILENAME);
        final Properties overwrite = getProperties(PROPERTIES_FILENAME);
        result.putAll(overwrite);
        return result;
    }

    /**
     * Get the properties from a file.
     *
     * @param filename The name of the properties file.
     * @return The properties.
     * @throws IOException If access to the specified file fails.
     * @throws java.io.FileNotFoundException
     */
    private static Properties getProperties(final String filename) throws IOException, FileNotFoundException {

        final Properties result = new Properties();
        final InputStream propertiesStream = getInputStream(filename);
        result.load(propertiesStream);
        return result;
    }

    /**
     * Get an InputStream for the given file.
     *
     * @param filename The name of the file.
     * @return The InputStream or null if the file could not be located.
     * @throws FileNotFoundException If access to the specified file fails.
     */
    private static InputStream getInputStream(final String filename) throws IOException, FileNotFoundException {
        final ResourcePatternResolver applicationContext = new ClassPathXmlApplicationContext(new String[] {});
        final Resource[] resource = applicationContext.getResources("classpath*:" + filename);
        if (resource.length == 0) {
            throw new FileNotFoundException("Unable to find file '" + filename + "' in classpath.");
        }
        return resource[0].getInputStream();
    }

}