Red Hat Summit 红帽全球峰会支持控制台（Console）开发人员开始试用联系人

此内容没有您所选择的语言版本。

Chapter 5. Develop Camel Applications in Spring Boot

5.1. Introduction to Camel Spring Boot
复制链接

Spring Boot component provides auto configuration for Apache Camel. Auto-configuration of the Camel context auto-detects Camel routes available in the Spring context and registers the key Camel utilities such as producer template, consumer template, and the type converter as beans.

Every Camel Spring Boot application should use dependencyManagement with productized versions, see quickstart pom. Versions that are tagged later can be omitted to not override the versions from BOM. 

<dependencyManagement>
	<dependencies>
		<dependency>
			<groupId>io.fabric8</groupId>
			<artifactId>fabric8-project-bom-camel-spring-boot</artifactId>
			<version>${fabric8.version}</version>
			<type>pom</type>
			<scope>import</scope>
		</dependency>
</dependencyManagement>
Copy to Clipboard Toggle word wrap
Note

camel-spring-boot jar comes with the spring.factories file which allows you to add that dependency into your classpath and hence Spring Boot will automatically auto-configure Camel.

5.2. Introduction to Camel Spring Boot Starter
复制链接

Apache Camel contains Spring Boot Starter module that allows you to develop Spring Boot applications using starters.

Note

For more details, see sample application in the source code.

To use the starter, add the following snippet to your Spring Boot pom.xml file: 

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-spring-boot-starter</artifactId>
</dependency>
Copy to Clipboard Toggle word wrap

The starter allows you to add classes with your Camel routes, as shown in the snippet below. Once these routes are added to the class path the routes are started automatically. 

package com.example;

import org.apache.camel.builder.RouteBuilder;
import org.springframework.stereotype.Component;

@Component
public class MyRoute extends RouteBuilder {

    @Override
    public void configure() throws Exception {
        from("timer:foo").to("log:bar");
    }
}
Copy to Clipboard Toggle word wrap
Note

You can customize the Camel application in the application.properties or application.yml file. 

5.3. Auto-configured Camel context
复制链接

Camel auto-configuration provides a CamelContext instance and creates a SpringCamelContext. It also initializes and performs shutdown of that context. This Camel context is registered in the Spring application context under camelContext bean name and you can access it like other Spring bean.

For example, you can access the camelContext as shown below: 

@Configuration
public class MyAppConfig {

  @Autowired
  CamelContext camelContext;

  @Bean
  MyService myService() {
    return new DefaultMyService(camelContext);
  }

}
Copy to Clipboard Toggle word wrap

5.4. Auto-detecting Camel routes
复制链接

Camel auto configuration collects all the RouteBuilder instances from the Spring context and automatically injects them into the CamelContext. It simplifies the process of creating new Camel route with the Spring Boot starter. You can create the routes by adding the @Component annotated class to your classpath. 

@Component
public class MyRouter extends RouteBuilder {

  @Override
  public void configure() throws Exception {
    from("jms:invoices").to("file:/invoices");
  }

}
Copy to Clipboard Toggle word wrap

To create a new route RouteBuilder bean in your @Configuration class, see below: 

@Configuration
public class MyRouterConfiguration {

  @Bean
  RoutesBuilder myRouter() {
    return new RouteBuilder() {

      @Override
      public void configure() throws Exception {
        from("jms:invoices").to("file:/invoices");
      }

    };
  }
 
}
Copy to Clipboard Toggle word wrap

5.5. Camel properties
复制链接

Spring Boot auto configuration automatically connects to Spring Boot external configuration such as properties placeholders, OS environment variables, or system properties with Camel properties support.

These properties are defined in application.properties file:   

route.from = jms:invoices
Copy to Clipboard Toggle word wrap

Use as system property 

java -Droute.to=jms:processed.invoices -jar mySpringApp.jar
Copy to Clipboard Toggle word wrap

Use as placeholders in Camel route: 

@Component
public class MyRouter extends RouteBuilder {

  @Override
  public void configure() throws Exception {
    from("{{route.from}}").to("{{route.to}}");
  }

}
Copy to Clipboard Toggle word wrap

5.6. Custom Camel context configuration
复制链接

To perform operations on CamelContext bean created by Camel auto configuration, you need to register CamelContextConfiguration instance in your Spring context as shown below: 

@Configuration
public class MyAppConfig {

  ...

  @Bean
  CamelContextConfiguration contextConfiguration() {
    return new CamelContextConfiguration() {
      @Override
      void beforeApplicationStart(CamelContext context) {
        // your custom configuration goes here
      }
    };
  }

}
Copy to Clipboard Toggle word wrap
Note

The method CamelContextConfiguration and beforeApplicationStart(CamelContext) will be called before the Spring context is started, so the CamelContext instance passed to this callback is fully auto-configured. You can add many instances of CamelContextConfiguration into your Spring context and all of them will be executed.

5.7. Disabling JMX
复制链接

To disable JMX of the auto-configured CamelContext use camel.springboot.jmxEnabled property as JMX is enabled by default.

For example, you could add the following property to your application.properties file: 

camel.springboot.jmxEnabled = false
Copy to Clipboard Toggle word wrap

5.8. Auto-configured consumer and producer templates
复制链接

Camel auto configuration provides pre-configured ConsumerTemplate and ProducerTemplate instances. You can inject them into your Spring-managed beans: 

@Component
public class InvoiceProcessor {

  @Autowired
  private ProducerTemplate producerTemplate;

  @Autowired
  private ConsumerTemplate consumerTemplate;
  public void processNextInvoice() {
    Invoice invoice = consumerTemplate.receiveBody("jms:invoices", Invoice.class);
    ...
    producerTemplate.sendBody("netty-http:http://invoicing.com/received/" + invoice.id());
  }

}
Copy to Clipboard Toggle word wrap

By default consumer templates and producer templates come with the endpoint cache sizes set to 1000. You can change those values using the following Spring properties: 

camel.springboot.consumerTemplateCacheSize = 100
camel.springboot.producerTemplateCacheSize = 200
Copy to Clipboard Toggle word wrap

5.9. Auto-configured TypeConverter
复制链接

Camel auto configuration registers a TypeConverter instance named typeConverter in the Spring context. 

@Component
public class InvoiceProcessor {

  @Autowired
  private TypeConverter typeConverter;

  public long parseInvoiceValue(Invoice invoice) {
    String invoiceValue = invoice.grossValue();
    return typeConverter.convertTo(Long.class, invoiceValue);
  }

}
Copy to Clipboard Toggle word wrap

5.10. Spring type conversion API bridge
复制链接

Spring consist of  type conversion API. Spring API is similar to the Camel type converter API. Due to the similarities between the two APIs Camel Spring Boot automatically registers a bridge converter (SpringTypeConverter) that delegates to the Spring conversion API. That means that out-of-the-box Camel will treat Spring Converters similar to Camel.

This allows you to access both Camel and Spring converters using the Camel TypeConverter API, as shown below: 

@Component
public class InvoiceProcessor {

  @Autowired
  private TypeConverter typeConverter;

  public UUID parseInvoiceId(Invoice invoice) {
    // Using Spring's StringToUUIDConverter
    UUID id = invoice.typeConverter.convertTo(UUID.class, invoice.getId());
  }

}
Copy to Clipboard Toggle word wrap

Here, Spring Boot delegates conversion to the Spring’s ConversionService instances available in the application context. If no ConversionService instance is available, Camel Spring Boot auto configuration creates an instance of ConversionService.

5.11. Disabling type conversions features
复制链接

To disable registering type conversion features of Camel Spring Boot such as TypeConverter instance or Spring bridge, set the camel.springboot.typeConversion property to false as shown below: 

camel.springboot.typeConversion = false
Copy to Clipboard Toggle word wrap

5.12. Adding XML routes
复制链接

By default, you can put Camel XML routes in the classpath under the directory camel, which camel-spring-boot will auto detect and include. From Camel version 2.17 onwards you can configure the directory name or disable this feature using the configuration option, as shown below: 

// turn off
camel.springboot.xmlRoutes = false
// scan in the com/foo/routes classpath
camel.springboot.xmlRoutes = classpath:com/foo/routes/*.xml
Copy to Clipboard Toggle word wrap
Note

The XML files should be Camel XML routes and not CamelContext such as: 

   <routes xmlns="http://camel.apache.org/schema/spring">
        <route id="test">
            <from uri="timer://trigger"/>
            <transform>
                <simple>ref:myBean</simple>
            </transform>
            <to uri="log:out"/>
        </route>
    </routes>
Copy to Clipboard Toggle word wrap

5.13. Adding XML Rest-DSL
复制链接

By default, you can put Camel Rest-DSL XML routes in the classpath under the directory camel-rest, which camel-spring-boot will auto detect and include. You can configure the directory name or disable this feature using the configuration option, as shown below: 

// turn off
camel.springboot.xmlRests = false
// scan in the com/foo/routes classpath
camel.springboot.xmlRests = classpath:com/foo/rests/*.xml
Copy to Clipboard Toggle word wrap
Note

The Rest-DSL XML files should be Camel XML rests and not CamelContext such as: 

   <rests xmlns="http://camel.apache.org/schema/spring">
      <rest>
         <post uri="/persons">
            <to uri="direct:postPersons"/>
         </post>
         <get uri="/persons">
            <to uri="direct:getPersons"/>
         </get>
         <get uri="/persons/{personId}">
             <to uri="direct:getPersionId"/>
         </get>
         <put uri="/persons/{personId}">
             <to uri="direct:putPersionId"/>
         </put>
         <delete uri="/persons/{personId}">
             <to uri="direct:deletePersionId"/>
         </delete>
      </rest>
    </rests>
Copy to Clipboard Toggle word wrap

5.14. See Also
复制链接

返回顶部
Red Hat logoGithubredditYoutubeTwitter

学习

尝试、购买和销售

社区

关于红帽文档

通过我们的产品和服务，以及可以信赖的内容，帮助红帽用户创新并实现他们的目标。 了解我们当前的更新.

让开源更具包容性

红帽致力于替换我们的代码、文档和 Web 属性中存在问题的语言。欲了解更多详情，请参阅红帽博客.

關於紅帽

我们提供强化的解决方案，使企业能够更轻松地跨平台和环境（从核心数据中心到网络边缘）工作。

Theme

© 2025 Red Hat