Chapter 115. Google Calendar Component

Available as of Camel version 2.15

The Google Calendar component provides access to http://google.com/calendar[Google Calendar] via the https://developers.google.com/google-apps/calendar/v3/reference/[Google Calendar Web APIs].

Google Calendar uses the https://developers.google.com/accounts/docs/OAuth2[OAuth 2.0 protocol] for authenticating a Google account and authorizing access to user data. Before you can use this component, you will need to https://developers.google.com/google-apps/calendar/auth[create an account and generate OAuth credentials]. Credentials comprise of a clientId, clientSecret, and a refreshToken. A handy resource for generating a long-lived refreshToken is the https://developers.google.com/oauthplayground[OAuth playground].

Maven users will need to add the following dependency to their pom.xml for this component:

    <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-google-calendar</artifactId>
            <version>2.15.0</version>
    </dependency>

115.1. 1. Google Calendar Options

The Google Calendar component supports 3 options which are listed below.

NameDescriptionDefaultType

configuration (common)

To use the shared configuration

 

GoogleCalendar Configuration

clientFactory (advanced)

To use the GoogleCalendarClientFactory as factory for creating the client. Will by default use BatchGoogleCalendarClientFactory

 

GoogleCalendarClient Factory

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The Google Calendar endpoint is configured using URI syntax:

google-calendar:apiName/methodName

with the following path and query parameters:

115.1.1. Path Parameters (2 parameters):

NameDescriptionDefaultType

apiName

Required What kind of operation to perform

 

GoogleCalendarApiName

methodName

Required What sub operation to use for the selected operation

 

String

115.1.2. Query Parameters (14 parameters):

NameDescriptionDefaultType

accessToken (common)

OAuth 2 access token. This typically expires after an hour so refreshToken is recommended for long term usage.

 

String

applicationName (common)

Google calendar application name. Example would be camel-google-calendar/1.0

 

String

clientId (common)

Client ID of the calendar application

 

String

clientSecret (common)

Client secret of the calendar application

 

String

emailAddress (common)

The emailAddress of the Google Service Account.

 

String

inBody (common)

Sets the name of a parameter to be passed in the exchange In Body

 

String

p12FileName (common)

The name of the p12 file which has the private key to use with the Google Service Account.

 

String

refreshToken (common)

OAuth 2 refresh token. Using this, the Google Calendar component can obtain a new accessToken whenever the current one expires - a necessity if the application is long-lived.

 

String

scopes (common)

Specifies the level of permissions you want a calendar application to have to a user account. You can separate multiple scopes by comma. See https://developers.google.com/google-apps/calendar/auth for more info.

https://www.googleapis.com/auth/calendar

String

user (common)

The email address of the user the application is trying to impersonate in the service account flow

 

String

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

 

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

 

ExchangePattern

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

115.2. URI Format

The GoogleCalendar Component uses the following URI format:

        google-calendar://endpoint-prefix/endpoint?[options]

Endpoint prefix can be one of:

  • acl
  • calendars
  • channels
  • colors
  • events
  • freebusy
  • list
  • settings

115.3. Producer Endpoints

Producer endpoints can use endpoint prefixes followed by endpoint names and associated options described next. A shorthand alias can be used for some endpoints. The endpoint URI MUST contain a prefix.

Endpoint options that are not mandatory are denoted by []. When there are no mandatory options for an endpoint, one of the set of [] options MUST be provided. Producer endpoints can also use a special option inBody that in turn should contain the name of the endpoint option whose value will be contained in the Camel Exchange In message.

Any of the endpoint options can be provided in either the endpoint URI, or dynamically in a message header. The message header name must be of the format CamelGoogleCalendar.<option>. Note that the inBody option overrides message header, i.e. the endpoint option inBody=option would override a CamelGoogleCalendar.option header.

115.4. Consumer Endpoints

Any of the producer endpoints can be used as a consumer endpoint. Consumer endpoints can use Scheduled Poll Consumer Options with a consumer. prefix to schedule endpoint invocation. Consumer endpoints that return an array or collection will generate one exchange per element, and their routes will be executed once for each exchange.

115.5. Message Headers

Any URI option can be provided in a message header for producer endpoints with a CamelGoogleCalendar. prefix.

115.6. Message Body

All result message bodies utilize objects provided by the underlying APIs used by the GoogleCalendarComponent. Producer endpoints can specify the option name for incoming message body in the inBody endpoint URI parameter. For endpoints that return an array or collection, a consumer endpoint will map every element to distinct messages.