Since Apache Camel 2.0, the org.apache.camel.ProducerTemplate class has been refactored so that sendBody methods now return void for InOnly messaging. Use one of the requestBody methods for InOut messaging. See Producer and Consumer Templates in Programming EIP Components for more details.

Since Apache Camel 2.0, all specializations of org.apache.camel.Exchange are now removed. You should now always use the org.apache.camel.impl.DefaultExchange type. After analyzing the how exchanges are used, it was realized that the specialized exchanges were not really necessary and by removing them we can avoid a lot of unnecessary copying and improve throughput.

One implication of this change is that Producer and Consumer types no longer use generic type declarations. For example, instead of referring to Producer<DefaultExchange> you can just refer to a plain Producer.

Since Apache Camel version 2.10, the containsSynchronization method has been added to the org.apache.camel.Exchange interface.

Since Apache Camel version 2.10, the isTransactionRedelivered method has been added to the org.apache.camel.Exchange interface.

Since Apache Camel 2.0, the getFault() and setFault() methods are now removed from Exchange. Faults represent application specific errors and are recognized by some protocols. Consequently, it makes more sense to store a fault as the Out message in an exchange (accessed using getOut() and setOut()). The org.apache.camel.Message interface now exposes the boolean isFault() and setFault() methods that are used to identify Out messages that represent faults.

Because faults represent persistent errors (as opposed to exceptions, which represent transient errors), Camel does not try (as in previous versions) to recover from them (for example, the error handler does not trigger) unless handling faults as exceptions is explicitly enabled.

Since Apache Camel 2.0, the following changes have been made to the implementation of org.apache.camel.processor.aggregate.AggregationStrategy:

Since Apache Camel 2.3, the aggregator has been re-implemented and some options have been replaced. In particular, the algorithms for determining batch completeness have changed significantly, so that the batchSize, outBatchSize, batchTimeout, and batchConsumer options are no longer supported. To understand the new mechanisms for completeness testing, it is recommended that you read Aggregator in Implementing Enterprise Integration Patterns.

Since Apache Camel version 2.1, the following changes have been made to the CamelContext class:

Since Apache Camel version 2.5, the following changes have been made to the CamelContext class:

Since Apache Camel version 2.10, the setManagementName method has been removed from org.apache.camel.CamelContext.

Since Apache Camel version 2.1, the org.apache.camel.spi.ManagementNamingStrategy has had methods renamed and method signatures changed in order to accomodate the JMX features in this release.

Since Apache Camel version 2.3, the begin() method from org.apache.camel.spi.PollingConsumerPollStrategy returns a boolean value, where true indicates that polling can now start, while false indicates that polling should be skipped.

Since Apache Camel version 2.3, the org.apache.camel.spi.RoutePolicy interface has the new method, onInit().

Since Apache Camel version 2.9, the org.apache.camel.spi.RoutePolicy interface has the following new methods: onRemove, onStart, onStop, onSuspend, and onResume.

Since Apache Camel version 2.3, the org.apache.camel.Message interface has the new method, removeHeaders().

Since Apache Camel version 2.10, the getBody(type) method and the getHeader(name, type) method from org.apache.camel.Message now throw TypeConversionException, if an exception occurs during type conversion.

Since Apache Camel version 2.3, the getExecutorService() and setExecutorService() methods have been removed from the org.apache.camel.impl.DefaultComponent and org.apache.camel.impl.DefaultEndpoint classes. To create a thread pool, use the ExecutorServiceManager object that is returned by the CamelContext.getExecutorServiceManager() method.

For full details of the new threading model, see Threading Model in Implementing Enterprise Integration Patterns.

If you have developed a custom component and you have implemented an endpoint by inheriting from the DefaultEndpoint class, it is strongly recommended that you override the doStart() and doStop() methods, instead of overriding the start() and stop() methods. Since Apache Camel version 2.7, the default endpoint implementation ensures that the doStart() and doStop() methods are called once and once only.

Since Apache Camel version 2.3, the org.apache.camel.component.file.GenericFile class is no longer serializable (does not inherit from java.io.Serializable).

Since Apache Camel version 2.10, the isDirectory method has been added to the org.apache.camel.component.file.GenericFile interface.

Since Apache Camel version 2.3, the adviceWith() method from org.apache.camel.model.RouteDefinition takes a CamelContext instance as its first parameter.

Since Apache Camel version 2.4, the toAsync() DSL command has been removed. Asynchronous dispatch is now implemented directly (where appropriate) in specific Apache Camel components and DSL commands.

Since Apache Camel version 2.4, the org.apache.camel.spi.Policy interface has the new method, beforeWrap(). For quick migration of your Policy classes, simply add an empty method implementation.

Since Apache Camel version 2.4, the retryUntil option on onException has been renamed to retryWhile, because this reflects the meaning of the option more accurately (it continues to retry while its argument is true).

Since Apache Camel version 2.4, you can use either a string or an expression to specify the name of the routing slip header. The Spring DSL has changed, such that the headerName attribute is now replaced by the headerName child element. For example, to specify the name of the routing slip header to be myHeader, use an XML fragment like the following:

<route>
  <from uri="direct:a"/>
  <routingSlip ignoreInvalidEndpoints="true">
    <headerName>myHeader</headerName>
  </routingSlip>
</route>  

Since Apache Camel version 2.4, all sendBody and requestBody methods from the ProducerTemplate class throw a CamelExecutionException, which wraps the original exception.

Since Apache Camel version 2.4, the simple and xpath expression builder methods are built into the RouteBuilder class. It is, therefore, no longer necessary to use static imports to access these languages. In your existing code, the Java compiler might complain, if you use static imports for simple and xpath. To fix this, just remove the static imports.

Since Apache Camel version 2.10, the errorHandler method from the org.apache.camel.builder.RouteBuilder interface returns void.

Since Apache Camel version 2.6, the org.apache.camel.spi.ManagementAware interface is deprecated. If you want to expose a bean through JMX, use the Spring JMX annotations instead.

For example, you would annotate a class using the Spring @ManagedResource annotation, and then annotate each managed attribute using @ManagedAttribute and each managed operation using @ManagedOperation—see the Spring Reference Guide for details.

Since Apache Camel version 2.6, when implementing a custom data format class, you can also optionally implement the Service and CamelContextAware interfaces in order to receive callbacks at initialization and shutdown time. For example, you can implement the MyCustomDataFormat class with callbacks, as follows:

// Java
...
public class MyCustomDataFormat implements DataFormat, Service, CamelContextAware {
    ...
}

Since Apache Camel version 2.6, the poll method in ScheduledPollConsumer now returns the number of messages actually processed from the poll.

Since Apache Camel version 2.7, the FATAL logging level has been removed from org.apache.camel.LoggingLevel. Use ERROR instead.

Since Apache Camel version 2.7, the getLeftValue() and getRightValue() methods have been removed from org.apache.camel.BinaryPredicate.

Since Apache Camel version 2.7, the parsePropertyValue() method from the org.apache.camel.component.properties.PropertiesParser interface has been renamed to parseProperty() and the signature has changed from:

// Java
// Versions prior to 2.7
String parsePropertyValue(String value);

To the new signature:

// Java
// Camel 2.7 or later
String parseProperty(String key, String value, Properties properties);

Since Apache Camel version 2.7, the sendBody and requestBody methods from the org.apache.camel.management.mbean.ManagedCamelContext take an Object instead of a String as their second parameter. Two new methods, sendStringBody and requestStringBody, have been added that take a String as their second parameter.

The new method signatures are as follows:

// NEW method signagures
void sendBody(String endpointUri, Object body);
Object requestBody(String endpointUri, Object body);
void sendStringBody(String endpointUri, String body);
Object requestStringBody(String endpointUri, String body);

Since Apache Camel version 2.8, the deprecated handled methods on errorHandler have been removed. If you need the functionality of the handled method (for example, to set handled(false)), you must migrate to use onException, which still supports the handled method.

Since Apache Camel version 2.8, the semantics of the wrapProcessorInInterceptors method from the org.apache.camel.spi.InterceptStrategy class have changed, so that the actual OutputDefinition instance is passed to wrapProcessorInInterceptors.

Since Apache Camel version 2.9, the org.apache.camel.spi.ExecutorServiceStrategy is deprecated in favor of the new ExecutorServiceManager class, which has a slightly reduced and improved API. For more details, see Threading Model in Implementing Enterprise Integration Patterns.

Since Apache Camel version 2.9, the org.apache.camel.component.ResourceBasedComponent class from camel-spring is deprecated. Use org.apache.camel.impl.DefaultComponent from camel-core instead.

Since Apache Camel version 2.9, the org.apache.camel.component.ResourceBasedEndpoint class from camel-spring is deprecated in favor of the new org.apache.camel.component.ResourceEndpoint in camel-core, and its dependency on Spring JARs has been removed. Use the new APIs on ResourceEndpoint to load resources.

Since Apache Camel version 2.9, the signature of the method, beforePoll, from the org.apache.camel.PollingConsumerPollingStrategy class has changed.

Since Apache Camel version 2.9, ServiceSupport does not handle child services any more. The new class, org.apache.camel.support.ChildServiceSupport, now handles this case. Additionally the org.apache.camel.StatefulService interface has been added, which provides access to ServiceSupport methods without knowing the implementation.

Since Apache Camel version 2.9, DataFormatResolver does not support the resolveDataFormatDefinition method anymore. The current implementations for OSGi and Default were exactly the same, so this code was moved to DefaultCamelContext.

Since Apache Camel version 2.9, all methods in CamelContext that reference model elements are deprecated. The new interface, org.apache.camel.model.ModelCamelContext, has been created to hold these methods

Since Apache Camel version 2.9, renameFile from org.apache.camel.util.FileUtil has a new copyAndDeleteOnRenameFail boolean option and throws IOException in case of an exception.

Since Apache Camel version 2.9, the context, template, and consumer fields in orb.apache.camel.test.CamelTestSupport are no longer static.

Since Apache Camel version 2.9, the org.apache.camel.WrappedFile interface has been introduced, as an abstraction of the GenericFile class, for use outside the file component.

Since Apache Camel version 2.9, all Spring-related methods in the org.apache.camel.builder.script.ScriptBuilder class have been removed (for example, methods taking org.springframework.core.io.Resource as an argument).

Since Apache Camel version 2.9, the org.apache.camel.builder.ErrorHandlerBuilder interface's configure method takes a org.apache.camel.spi.RouteContext argument.

Since Apache Camel version 2.10, the shutdownForced and forceShutdown methods have been added to the org.apache.camel.spi.ShutdownStrategy interface.

Since Apache Camel version 2.10, the ShutdownAware interface inherits from the ShutdownPrepared interface, which defines the additional prepareShutdown method.

Since Apache Camel version 2.10, the SimpleLanguage constructor that takes custom start and end tokens has been removed. Use the static SimpleLanguage.changeFunctionStartToken method and the SimpleLanguage.changeFunctionEndToken method instead.

Since Apache Camel version 2.10, the onThreadPoolRemove method and the onErrorHandlerRemove method have been added to the org.apache.camel.spi.LifecycleStrategy interface.

Since Apache Camel version 2.10, the retryWhile(Expression) method has been removed from the org.apache.camel.model.OnExceptionDefinition interface. Use the retryWhile(Predicate) method instead.

Since Apache Camel version 2.10, the convertTo methods on org.apache.camel.TypeConverter throw TypeConversionException, if an exception occurs during type conversion. New tryConvertTo methods have been added to TypeConverter, which ignore any exceptions that might occur during conversion.

Since Apache Camel version 2.10, the containsSynchronization method has been added to the org.apache.camel.spi.UnitOfWork interface.

Since Apache Camel version 2.10, the getStatistics method has been added to the org.apache.camel.spi.TypeConverterRegistry interface.

Since Apache Camel version 2.10, the abort method has been added to the org.apache.camel.component.file.GenericFileProcessStrategy interface.