Chapter 122. Google Mail Component

Available as of Camel version 2.15

The Google Mail component provides access to Gmail via the Google Mail Web APIs.

Google Mail uses the 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 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 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-mail</artifactId>
            <version>2.15-SNAPSHOT</version>
    </dependency>

122.1. URI Format

The GoogleMail Component uses the following URI format:

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

Endpoint prefix can be one of:

  • attachments
  • drafts
  • history
  • labels
  • messages
  • threads
  • users

122.2. GoogleMailComponent

The Google Mail component supports 3 options, which are listed below.

NameDescriptionDefaultType

configuration (common)

To use the shared configuration

 

GoogleMailConfiguration

clientFactory (advanced)

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

 

GoogleMailClient 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 Mail endpoint is configured using URI syntax:

google-mail:apiName/methodName

with the following path and query parameters:

122.2.1. Path Parameters (2 parameters):

NameDescriptionDefaultType

apiName

Required What kind of operation to perform

 

GoogleMailApiName

methodName

Required What sub operation to use for the selected operation

 

String

122.2.2. Query Parameters (10 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 mail application name. Example would be camel-google-mail/1.0

 

String

clientId (common)

Client ID of the mail application

 

String

clientSecret (common)

Client secret of the mail application

 

String

inBody (common)

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

 

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

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 option 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

122.3. Spring Boot Auto-Configuration

The component supports 10 options, which are listed below.

NameDescriptionDefaultType

camel.component.google-mail.client-factory

To use the GoogleCalendarClientFactory as factory for creating the client. Will by default use BatchGoogleMailClientFactory. The option is a org.apache.camel.component.google.mail.GoogleMailClientFactory type.

 

String

camel.component.google-mail.configuration.access-token

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

 

String

camel.component.google-mail.configuration.api-name

What kind of operation to perform

 

GoogleMailApiName

camel.component.google-mail.configuration.application-name

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

 

String

camel.component.google-mail.configuration.client-id

Client ID of the mail application

 

String

camel.component.google-mail.configuration.client-secret

Client secret of the mail application

 

String

camel.component.google-mail.configuration.method-name

What sub operation to use for the selected operation

 

String

camel.component.google-mail.configuration.refresh-token

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

camel.component.google-mail.enabled

Enable google-mail component

true

Boolean

camel.component.google-mail.resolve-property-placeholders

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

true

Boolean

122.4. 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 CamelGoogleMail.<option>. Note that the inBody option overrides message header, i.e. the endpoint option inBody=option would override a CamelGoogleMail.option header.

For more information on the endpoints and options see API documentation at: https://developers.google.com/gmail/api/v1/reference/

122.5. 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.

122.6. Message Headers

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

122.7. Message Body

All result message bodies utilize objects provided by the underlying APIs used by the GoogleMailComponent. 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.