Create cloud provider from properties

gistfile1.txt

    public void loadProviderFromProperties() throws Exception {
        final Properties props = new Properties();
        InputStream inputStream = new FileInputStream("/Users/stas/dsn.properties");
        try {
            props.load(inputStream);
        } catch( IOException e ) {
            e.printStackTrace();
        }

        Cloud cloud = Cloud.register(props.getProperty("DSN_PROVIDER_NAME"),
                props.getProperty("DSN_CLOUD_NAME"),
                props.getProperty("DSN_ENDPOINT"),
                (Class<? extends CloudProvider>)Class.forName(props.getProperty("DSN_PROVIDER_CLASS")));
        // Find what additional fields are necessary to connect to the cloud
        ContextRequirements requirements = cloud.buildProvider().getContextRequirements();
        List<ContextRequirements.Field> fields = requirements.getConfigurableValues();

        // Load the values for the required fields from the system properties
        List<ProviderContext.Value<?>> values = new ArrayList<ProviderContext.Value<?>>();
        int i = 0;

        for(ContextRequirements.Field f : fields ) {
            System.out.print("Loading '" + f.name + "' from ");
            if( f.type.equals(ContextRequirements.FieldType.KEYPAIR) ) {
                System.out.println("'DSN_" + f.name + "_SHARED' and 'DSN_" + f.name + "_SECRET'");
                String shared = props.getProperty("DSN_" + f.name + "_SHARED");
                String secret = props.getProperty("DSN_" + f.name + "_SECRET");
                System.out.println(secret);
                values.add(ProviderContext.Value.parseValue(f, shared, secret));
            }
            else {
                System.out.println("'DSN_" + f.name + "'");
                String value = props.getProperty("DSN_" + f.name);
                if( value != null ) {
                    values.add(ProviderContext.Value.parseValue(f, value));
                }
            }
            i++;
        }

        ProviderContext ctx = cloud.createContext(props.getProperty("DSN_ACCOUNT"), props.getProperty("DSN_REGION"), values.toArray(new ProviderContext.Value<?>[0]));
        CloudProvider configuredProvider = ctx.connect();
        MachineImage mi = configuredProvider.getComputeServices().getImageSupport().getImage("bogus");
        System.out.println("All done");
    }