Spring Batch

URI format

spring-batch:jobName[?options]

Where jobName represents the name of the Spring Batch job located in the Camel registry. Alternatively, if a JobRegistry is provided, it will be used to locate the job instead.

This component can only be used to define producer endpoints, which means that you cannot use the Spring Batch component in a from() statement.

Configuring Options

Camel components are configured on two separate levels:

component level
endpoint level

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.

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.

Component Options

The Spring Batch component supports 4 options, which are listed below.

Name	Description	Default	Type
jobLauncher (producer)	Explicitly specifies a JobLauncher to be used.		JobLauncher
jobRegistry (producer)	Explicitly specifies a JobRegistry to be used.		JobRegistry
lazyStartProducer (producer)	Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.	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

Name

Description

Default

Type

jobLauncher (producer)

Explicitly specifies a JobLauncher to be used.

JobLauncher

jobRegistry (producer)

Explicitly specifies a JobRegistry to be used.

JobRegistry

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

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

Endpoint Options

The Spring Batch endpoint is configured using URI syntax:

spring-batch:jobName

With the following path and query parameters:

Path Parameters (1 parameters)

Name	Description	Default	Type
jobName (producer)	Required The name of the Spring Batch job located in the registry.		String

Name

Description

Default

Type

jobName (producer)

Required The name of the Spring Batch job located in the registry.

String

Query Parameters (4 parameters)

Name	Description	Default	Type
jobFromHeader (producer)	Explicitly defines if the jobName should be taken from the headers instead of the URI.	false	boolean
jobLauncher (producer)	Explicitly specifies a JobLauncher to be used.		JobLauncher
jobRegistry (producer)	Explicitly specifies a JobRegistry to be used.		JobRegistry
lazyStartProducer (producer (advanced))	Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.	false	boolean

Name

Description

Default

Type

jobFromHeader (producer)

Explicitly defines if the jobName should be taken from the headers instead of the URI.

false

boolean

jobLauncher (producer)

Explicitly specifies a JobLauncher to be used.

JobLauncher

jobRegistry (producer)

Explicitly specifies a JobRegistry to be used.

JobRegistry

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

Usage

When the Spring Batch component receives the message, it triggers the job execution. The job will be executed using the org.springframework.batch.core.launch.JobLaucher instance resolved according to the following algorithm:

if JobLauncher is manually set on the component, then use it.
if jobLauncherRef option is set on the component, then search Camel Registry for the JobLauncher with the given name. Deprecated and will be removed in Camel 3.0!
if there is JobLauncher registered in the Camel Registry under jobLauncher name, then use it.
if none of the steps above allow resolving the JobLauncher and there is exactly one JobLauncher instance in the Camel Registry, then use it.

All headers found in the message are passed to the JobLauncher as job parameters. String, Long, Double and java.util.Date values are copied to the org.springframework.batch.core.JobParametersBuilder - other data types are converted to Strings.

Examples

Triggering the Spring Batch job execution:

from("direct:startBatch").to("spring-batch:myJob");

Triggering the Spring Batch job execution with the JobLauncher set explicitly.

from("direct:startBatch").to("spring-batch:myJob?jobLauncherRef=myJobLauncher");

A JobExecution instance returned by the JobLauncher is forwarded by the SpringBatchProducer as the output message. You can use the JobExecution instance to perform some operations using the Spring Batch API directly.

from("direct:startBatch").to("spring-batch:myJob").to("mock:JobExecutions");
...
MockEndpoint mockEndpoint = ...;
JobExecution jobExecution = mockEndpoint.getExchanges().get(0).getIn().getBody(JobExecution.class);
BatchStatus currentJobStatus = jobExecution.getStatus();

Support classes

Apart from the Component, Camel Spring Batch provides also support classes, which can be used to hook into Spring Batch infrastructure.

CamelItemReader

CamelItemReader can be used to read batch data directly from the Camel infrastructure.

For example, the snippet below is configuring Spring Batch to read data from JMS queue.

<bean id="camelReader" class="org.apache.camel.component.spring.batch.support.CamelItemReader">
  <constructor-arg ref="consumerTemplate"/>
  <constructor-arg value="jms:dataQueue"/>
</bean>

<batch:job id="myJob">
  <batch:step id="step">
    <batch:tasklet>
      <batch:chunk reader="camelReader" writer="someWriter" commit-interval="100"/>
    </batch:tasklet>
  </batch:step>
</batch:job>

CamelItemWriter

CamelItemWriter has similar purpose as CamelItemReader, but it is dedicated to write chunk of the processed data.

For example, the snippet below is configuring Spring Batch to read data from JMS queue.

<bean id="camelwriter" class="org.apache.camel.component.spring.batch.support.CamelItemWriter">
  <constructor-arg ref="producerTemplate"/>
  <constructor-arg value="jms:dataQueue"/>
</bean>

<batch:job id="myJob">
  <batch:step id="step">
    <batch:tasklet>
      <batch:chunk reader="someReader" writer="camelwriter" commit-interval="100"/>
    </batch:tasklet>
  </batch:step>
</batch:job>

CamelItemProcessor

CamelItemProcessor is the implementation of Spring Batch org.springframework.batch.item.ItemProcessor interface. The latter implementation relays on the Request Reply pattern to delegate the processing of the batch item to the Camel infrastructure. The item to process is sent to the Camel endpoint as the body of the message.

For example, the snippet below performs simple processing of the batch item using the Direct endpoint and the Simple expression language.

<camel:camelContext>
  <camel:route>
    <camel:from uri="direct:processor"/>
    <camel:setExchangePattern pattern="InOut"/>
    <camel:setBody>
      <camel:simple>Processed ${body}</camel:simple>
    </camel:setBody>
  </camel:route>
</camel:camelContext>

<bean id="camelProcessor" class="org.apache.camel.component.spring.batch.support.CamelItemProcessor">
  <constructor-arg ref="producerTemplate"/>
  <constructor-arg value="direct:processor"/>
</bean>

<batch:job id="myJob">
  <batch:step id="step">
    <batch:tasklet>
      <batch:chunk reader="someReader" writer="someWriter" processor="camelProcessor" commit-interval="100"/>
    </batch:tasklet>
  </batch:step>
</batch:job>

CamelJobExecutionListener

CamelJobExecutionListener is the implementation of the org.springframework.batch.core.JobExecutionListener interface sending job execution events to the Camel endpoint.

The org.springframework.batch.core.JobExecution instance produced by the Spring Batch is sent as a body of the message. To distinguish between before- and after-callbacks SPRING_BATCH_JOB_EVENT_TYPE header is set to the BEFORE or AFTER value.

The example snippet below sends Spring Batch job execution events to the JMS queue.

<bean id="camelJobExecutionListener" class="org.apache.camel.component.spring.batch.support.CamelJobExecutionListener">
  <constructor-arg ref="producerTemplate"/>
  <constructor-arg value="jms:batchEventsBus"/>
</bean>

<batch:job id="myJob">
  <batch:step id="step">
    <batch:tasklet>
      <batch:chunk reader="someReader" writer="someWriter" commit-interval="100"/>
    </batch:tasklet>
  </batch:step>
  <batch:listeners>
    <batch:listener ref="camelJobExecutionListener"/>
  </batch:listeners>
</batch:job>

Spring Boot Auto-Configuration

When using spring-batch with 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-spring-batch-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 5 options, which are listed below.

Name	Description	Default	Type
camel.component.spring-batch.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.spring-batch.enabled	Whether to enable auto configuration of the spring-batch component. This is enabled by default.		Boolean
camel.component.spring-batch.job-launcher	Explicitly specifies a JobLauncher to be used. The option is a org.springframework.batch.core.launch.JobLauncher type.		JobLauncher
camel.component.spring-batch.job-registry	Explicitly specifies a JobRegistry to be used. The option is a org.springframework.batch.core.configuration.JobRegistry type.		JobRegistry
camel.component.spring-batch.lazy-start-producer	Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.	false	Boolean

Name

Description

Default

Type

camel.component.spring-batch.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.spring-batch.enabled

Whether to enable auto configuration of the spring-batch component. This is enabled by default.

Boolean

camel.component.spring-batch.job-launcher

Explicitly specifies a JobLauncher to be used. The option is a org.springframework.batch.core.launch.JobLauncher type.

JobLauncher

camel.component.spring-batch.job-registry

Explicitly specifies a JobRegistry to be used. The option is a org.springframework.batch.core.configuration.JobRegistry type.

JobRegistry

camel.component.spring-batch.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean