Chapter 142. Timer
Chapter 142. Timer Only consumer is supported The Timer component is used to generate message exchanges when a timer fires You can only consume events from this endpoint. 142.1. Dependencies When using timer with Red Hat build of Camel Spring Boot make sure to use the following Maven dependency to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-timer-starter</artifactId> </dependency> 142.2. URI format Where name is the name of the Timer object, which is created and shared across endpoints. So if you use the same name for all your timer endpoints, only one Timer object and thread will be used. Note The IN body of the generated exchange is null . So exchange.getIn().getBody() returns null . Note Advanced Scheduler See also the Quartz component that supports much more advanced scheduling. 142.3. Configuring Options Camel components are configured on two separate levels: component level endpoint level 142.3.1. Configuring Component Options At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level. For example, a component may have security settings, credentials for authentication, urls for network connection and so forth. Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all. You can configure components using: the Component DSL . in a configuration file (application.properties, *.yaml files, etc). directly in the Java code. 142.3.2. Configuring Endpoint Options You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both. Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java. A good practice when configuring options is to use Property Placeholders . Property placeholders provide a few benefits: They help prevent using hardcoded urls, port numbers, sensitive information, and other settings. They allow externalizing the configuration from the code. They help the code to become more flexible and reusable. The following two sections list all the options, firstly for the component followed by the endpoint. 142.4. Component Options The Timer component supports 2 options, which are listed below. Name Description Default Type 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 autowiredEnabled (advanced) Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true boolean 142.5. Endpoint Options The Timer endpoint is configured using URI syntax: with the following path and query parameters: 142.5.1. Path Parameters (1 parameters) Name Description Default Type timerName (consumer) Required The name of the timer. String 142.5.2. Query Parameters (13 parameters) Name Description Default Type 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 delay (consumer) Delay before first event is triggered. 1000 long fixedRate (consumer) Events take place at approximately regular intervals, separated by the specified period. false boolean includeMetadata (consumer) Whether to include metadata in the exchange such as fired time, timer name, timer count etc. This information is default included. true boolean period (consumer) If greater than 0, generate periodic events every period. 1000 long repeatCount (consumer) Specifies a maximum limit of number of fires. So if you set it to 1, the timer will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever. long exceptionHandler (consumer (advanced)) 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 (advanced)) Sets the exchange pattern when the consumer creates an exchange. Enum values: InOnly InOut InOptionalOut ExchangePattern daemon (advanced) Specifies whether or not the thread associated with the timer endpoint runs as a daemon. The default value is true. true boolean pattern (advanced) Allows you to specify a custom Date pattern to use for setting the time option using URI syntax. String synchronous (advanced) Sets whether synchronous processing should be strictly used. false boolean time (advanced) A java.util.Date the first event should be generated. If using the URI, the pattern expected is: yyyy-MM-dd HH:mm:ss or yyyy-MM-dd'T'HH:mm:ss. Date timer (advanced) To use a custom Timer. Timer 142.6. Exchange Properties When the timer is fired, it adds the following information as properties to the Exchange : Name Type Description Exchange.TIMER_NAME String The value of the name option. Exchange.TIMER_TIME Date The value of the time option. Exchange.TIMER_PERIOD long The value of the period option. Exchange.TIMER_FIRED_TIME Date The time when the consumer fired. Exchange.TIMER_COUNTER Long The current fire counter. Starts from 1. 142.7. Sample To set up a route that generates an event every 60 seconds: from("timer://foo?fixedRate=true&period=60000").to("bean:myBean?method=someMethodName"); The above route will generate an event and then invoke the someMethodName method on the bean called myBean in the Registry. And the route in Spring DSL: <route> <from uri="timer://foo?fixedRate=true&amp;period=60000"/> <to uri="bean:myBean?method=someMethodName"/> </route> 142.8. Firing as soon as possible Since Camel 2.17 You may want to fire messages in a Camel route as soon as possible you can use a negative delay: <route> <from uri="timer://foo?delay=-1"/> <to uri="bean:myBean?method=someMethodName"/> </route> In this way the timer will fire messages immediately. You can also specify a repeatCount parameter in conjunction with a negative delay to stop firing messages after a fixed number has been reached. If you don't specify a repeatCount then the timer will continue firing messages until the route will be stopped. 142.9. Firing only once You may want to fire a message in a Camel route only once, such as when starting the route. To do that you use the repeatCount option as shown: <route> <from uri="timer://foo?repeatCount=1"/> <to uri="bean:myBean?method=someMethodName"/> </route> 142.10. Spring Boot Auto-Configuration The component supports 3 options, which are listed below. Name Description Default Type camel.component.timer.autowired-enabled Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. true Boolean camel.component.timer.bridge-error-handler 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 camel.component.timer.enabled Whether to enable auto configuration of the timer component. This is enabled by default. Boolean
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-timer-starter</artifactId> </dependency> timer:name[?options] timer:timerName from("timer://foo?fixedRate=true&period=60000").to("bean:myBean?method=someMethodName"); <route> <from uri="timer://foo?fixedRate=true&amp;period=60000"/> <to uri="bean:myBean?method=someMethodName"/> </route> <route> <from uri="timer://foo?delay=-1"/> <to uri="bean:myBean?method=someMethodName"/> </route> <route> <from uri="timer://foo?repeatCount=1"/> <to uri="bean:myBean?method=someMethodName"/> </route>