private RepositoryConfig createRepositoryConfig(Properties properties) throws MojoExecutionException{
		
		String driverClass = this.databaseDriverClass;
		String username = this.databaseUsername;
		String password = this.databasePassword;
		String url = this.databaseUrl;
		
		if (Strings.isNullOrEmpty(driverClass) && Strings.isNullOrEmpty((driverClass = properties.getProperty("database.driver.class")))){
			throw new MojoExecutionException("Driver class must not be null");
		}
		
		if (Strings.isNullOrEmpty(username) && Strings.isNullOrEmpty((username = properties.getProperty("database.username")))){
			throw new MojoExecutionException("Database username must not be null");
		}
		
		if (Strings.isNullOrEmpty(password) && Strings.isNullOrEmpty((password = properties.getProperty("database.password")))){
			throw new MojoExecutionException("Database password must not be null");
		}
		
		if (Strings.isNullOrEmpty(url) && Strings.isNullOrEmpty((url = properties.getProperty("database.url")))){
			throw new MojoExecutionException("Database url must not be null");
		}
		
		
		try {
			return new RepositoryConfig(Class.forName(driverClass), username, password, url);
		} catch (ClassNotFoundException exception) {
			throw new MojoExecutionException(exception.getMessage(), exception);
		}
	}