Chapter 123. Google Mail Stream Component Available as of Camel version 2.22 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: 123.1. URI Format The GoogleMail Component uses the following URI format: 123.2. GoogleMailStreamComponent The Google Mail Stream component supports 3 options, which are listed below. Name Description Default Type configuration (advanced) The configuration GoogleMailStream Configuration clientFactory (advanced) The client Factory 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 Stream endpoint is configured using URI syntax: with the following path and query parameters: 123.2.1. Path Parameters (1 parameters): Name Description Default Type index Specifies an index for the endpoint String 123.2.2. Query Parameters (28 parameters): Name Description Default Type accessToken (consumer) OAuth 2 access token. This typically expires after an hour so refreshToken is recommended for long term usage. String applicationName (consumer) Google mail application name. Example would be camel-google-mail/1.0 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 clientId (consumer) Client ID of the mail application String clientSecret (consumer) Client secret of the mail application String labels (consumer) Comma separated list of labels to take into account String markAsRead (consumer) Mark the message as read once it has been consumed false boolean maxResults (consumer) Max results to be returned 10 long query (consumer) The query to execute on gmail box is:unread String refreshToken (consumer) 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 sendEmptyMessageWhenIdle (consumer) If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead. 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 pollStrategy (consumer) A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel. PollingConsumerPoll Strategy synchronous (advanced) Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). false boolean backoffErrorThreshold (scheduler) The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in. int backoffIdleThreshold (scheduler) The number of subsequent idle polls that should happen before the backoffMultipler should kick-in. int backoffMultiplier (scheduler) To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured. int delay (scheduler) Milliseconds before the poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). 500 long greedy (scheduler) If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the run polled 1 or more messages. false boolean initialDelay (scheduler) Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). 1000 long runLoggingLevel (scheduler) The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that. TRACE LoggingLevel scheduledExecutorService (scheduler) Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool. ScheduledExecutor Service scheduler (scheduler) To use a cron scheduler from either camel-spring or camel-quartz2 component none ScheduledPollConsumer Scheduler schedulerProperties (scheduler) To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler. Map startScheduler (scheduler) Whether the scheduler should be auto started. true boolean timeUnit (scheduler) Time unit for initialDelay and delay options. MILLISECONDS TimeUnit useFixedDelay (scheduler) Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details. true boolean 123.3. Spring Boot Auto-Configuration The component supports 13 options, which are listed below. Name Description Default Type camel.component.google-mail-stream.client-factory The client Factory. The option is a org.apache.camel.component.google.mail.GoogleMailClientFactory type. String camel.component.google-mail-stream.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-stream.configuration.application-name Google mail application name. Example would be camel-google-mail/1.0 String camel.component.google-mail-stream.configuration.client-id Client ID of the mail application String camel.component.google-mail-stream.configuration.client-secret Client secret of the mail application String camel.component.google-mail-stream.configuration.index Specifies an index for the endpoint String camel.component.google-mail-stream.configuration.labels Comma separated list of labels to take into account String camel.component.google-mail-stream.configuration.mark-as-read Mark the message as read once it has been consumed false Boolean camel.component.google-mail-stream.configuration.max-results Max results to be returned 10 Long camel.component.google-mail-stream.configuration.query The query to execute on gmail box is:unread String camel.component.google-mail-stream.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-stream.enabled Whether to enable auto configuration of the google-mail-stream component. This is enabled by default. Boolean camel.component.google-mail-stream.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 123.4. Consumer The consumer will poll by default with the query "is:unread" and maxResults equals to 10. For example from("google-mail-stream://test?markAsRead=true&delay=5000&maxResults=5&labels=GitHub,Apache").to("mock:result"); This route will consume unread messages with labels Github and Apache and it will mark the messages as read.

Commands:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-google-mail</artifactId> <version>2.22-SNAPSHOT</version> </dependency>
google-mail-stream://index?[options]
google-mail-stream:index
from("google-mail-stream://test?markAsRead=true&delay=5000&maxResults=5&labels=GitHub,Apache").to("mock:result");