Chapter 121. 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>121.1. 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
121.2. GoogleMailComponent
The Google Mail component supports 3 options which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| 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:
121.2.1. Path Parameters (2 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| apiName | Required What kind of operation to perform | GoogleMailApiName | |
| methodName | Required What sub operation to use for the selected operation | String |
121.2.2. Query Parameters (11 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| 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 | |
| scopes (common) | Specifies the level of permissions you want a mail application to have to a user account. See https://developers.google.com/gmail/api/auth/scopes for more info. | List | |
| 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 |
121.3. 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 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/
121.4. 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.
121.5. Message Headers
Any URI option can be provided in a message header for producer endpoints with a CamelGoogleMail. prefix.
121.6. 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.
