Azure ServiceBus
Since Camel 3.12
Both producer and consumer are supported
The azure-servicebus component that integrates Azure ServiceBus. Azure ServiceBus is a fully managed enterprise integration message broker. Service Bus can decouple applications and services. Service Bus offers a reliable and secure platform for asynchronous transfer of data and state. Data is transferred between different applications and services using messages.
Prerequisites
You must have a valid Windows Azure Storage account. More information is available at Azure Documentation Portal.
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-azure-servicebus</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
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 Azure ServiceBus component supports 27 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
Sets the retry options for Service Bus clients. If not specified, the default retry options are used. | AmqpRetryOptions | ||
Sets the transport type by which all the communication with Azure Service Bus occurs. Default value is AMQP. Enum values:
| AMQP | AmqpTransportType | |
Sets the ClientOptions to be sent from the client built from this builder, enabling customization of certain properties, as well as support the addition of custom header information. | ClientOptions | ||
The component configurations. | ServiceBusConfiguration | ||
To use a custom HeaderFilterStrategy to filter Service Bus application properties to and from Camel message headers. | HeaderFilterStrategy | ||
Sets the proxy configuration to use for ServiceBusSenderClient. When a proxy is configured, AMQP_WEB_SOCKETS must be used for the transport type. | ProxyOptions | ||
Required The service bus type of connection to execute. Queue is for typical queue option and topic for subscription based model. Enum values:
| queue | ServiceBusType | |
Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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 | |
Enable application level deadlettering to the subscription deadletter subqueue if deadletter related headers are set. | false | boolean | |
Sets the amount of time to continue auto-renewing the lock. Setting ZERO disables auto-renewal. For ServiceBus receive mode (RECEIVE_AND_DELETE RECEIVE_AND_DELETE), auto-renewal is disabled. | 5m | Duration | |
Sets maximum number of concurrent calls. | 1 | int | |
Sets the prefetch count of the receiver. For both PEEK_LOCK PEEK_LOCK and RECEIVE_AND_DELETE RECEIVE_AND_DELETE receive modes the default value is 1. Prefetch speeds up the message flow by aiming to have a message readily available for local retrieval when and before the application asks for one using receive message. Setting a non-zero value will prefetch that number of messages. Setting the value to zero turns prefetch off. | int | ||
Autowired Sets the processorClient in order to consume messages by the consumer. | ServiceBusProcessorClient | ||
Sets the receive mode for the receiver. Enum values:
| PEEK_LOCK | ServiceBusReceiveMode | |
Sets the type of the SubQueue to connect to. Enum values:
| SubQueue | ||
Sets the name of the subscription in the topic to listen to. topicOrQueueName and serviceBusType=topic must also be set. This property is required if serviceBusType=topic and the consumer is in use. | String | ||
Set binary mode. If true, message body will be sent as byte. By default, it is false. | false | boolean | |
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 | |
Sets the desired operation to be used in the producer. Enum values:
| sendMessages | ServiceBusProducerOperationDefinition | |
Sets OffsetDateTime at which the message should appear in the Service Bus queue or topic. | OffsetDateTime | ||
Autowired Sets senderClient to be used in the producer. | ServiceBusSenderClient | ||
Represents transaction in service. This object just contains transaction id. | ServiceBusTransactionContext | ||
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 | |
Sets the connection string for a Service Bus namespace or a specific Service Bus resource. | String | ||
Determines the credential strategy to adopt. Enum values:
| CONNECTION_STRING | CredentialType | |
Fully Qualified Namespace of the service bus. | String | ||
A TokenCredential for Azure AD authentication. | TokenCredential |
Endpoint Options
The Azure ServiceBus endpoint is configured using URI syntax:
azure-servicebus:topicOrQueueName
With the following path and query parameters:
Query Parameters (27 parameters)
Name | Description | Default | Type |
---|---|---|---|
Sets the retry options for Service Bus clients. If not specified, the default retry options are used. | AmqpRetryOptions | ||
Sets the transport type by which all the communication with Azure Service Bus occurs. Default value is AMQP. Enum values:
| AMQP | AmqpTransportType | |
Sets the ClientOptions to be sent from the client built from this builder, enabling customization of certain properties, as well as support the addition of custom header information. | ClientOptions | ||
To use a custom HeaderFilterStrategy to filter Service Bus application properties to and from Camel message headers. | HeaderFilterStrategy | ||
Sets the proxy configuration to use for ServiceBusSenderClient. When a proxy is configured, AMQP_WEB_SOCKETS must be used for the transport type. | ProxyOptions | ||
Required The service bus type of connection to execute. Queue is for typical queue option and topic for subscription based model. Enum values:
| queue | ServiceBusType | |
Enable application level deadlettering to the subscription deadletter subqueue if deadletter related headers are set. | false | boolean | |
Sets the amount of time to continue auto-renewing the lock. Setting ZERO disables auto-renewal. For ServiceBus receive mode (RECEIVE_AND_DELETE RECEIVE_AND_DELETE), auto-renewal is disabled. | 5m | Duration | |
Sets maximum number of concurrent calls. | 1 | int | |
Sets the prefetch count of the receiver. For both PEEK_LOCK PEEK_LOCK and RECEIVE_AND_DELETE RECEIVE_AND_DELETE receive modes the default value is 1. Prefetch speeds up the message flow by aiming to have a message readily available for local retrieval when and before the application asks for one using receive message. Setting a non-zero value will prefetch that number of messages. Setting the value to zero turns prefetch off. | int | ||
Autowired Sets the processorClient in order to consume messages by the consumer. | ServiceBusProcessorClient | ||
Sets the receive mode for the receiver. Enum values:
| PEEK_LOCK | ServiceBusReceiveMode | |
Sets the type of the SubQueue to connect to. Enum values:
| SubQueue | ||
Sets the name of the subscription in the topic to listen to. topicOrQueueName and serviceBusType=topic must also be set. This property is required if serviceBusType=topic and the consumer is in use. | String | ||
Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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 | |
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 | ||
Sets the exchange pattern when the consumer creates an exchange. Enum values:
| ExchangePattern | ||
Set binary mode. If true, message body will be sent as byte. By default, it is false. | false | boolean | |
Sets the desired operation to be used in the producer. Enum values:
| sendMessages | ServiceBusProducerOperationDefinition | |
Sets OffsetDateTime at which the message should appear in the Service Bus queue or topic. | OffsetDateTime | ||
Autowired Sets senderClient to be used in the producer. | ServiceBusSenderClient | ||
Represents transaction in service. This object just contains transaction id. | ServiceBusTransactionContext | ||
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 | |
Sets the connection string for a Service Bus namespace or a specific Service Bus resource. | String | ||
Determines the credential strategy to adopt. Enum values:
| CONNECTION_STRING | CredentialType | |
Fully Qualified Namespace of the service bus. | String | ||
A TokenCredential for Azure AD authentication. | TokenCredential |
Message Headers
The Azure ServiceBus component supports 25 message header(s), which is/are listed below:
Name | Description | Default | Type |
---|---|---|---|
CamelAzureServiceBusApplicationProperties (common) Constant: | The application properties (also known as custom properties) on messages sent and received by the producer and consumer, respectively. | Map | |
CamelAzureServiceBusContentType (consumer) Constant: | Gets the content type of the message. | String | |
CamelAzureServiceBusDeadLetterErrorDescription (consumer) Constant: | Gets the description for a message that has been dead-lettered. | String | |
CamelAzureServiceBusDeadLetterReason (consumer) Constant: | Gets the reason a message was dead-lettered. | String | |
CamelAzureServiceBusDeadLetterSource (consumer) Constant: | Gets the name of the queue or subscription that this message was enqueued on, before it was dead-lettered. | String | |
CamelAzureServiceBusDeliveryCount (consumer) Constant: | Gets the number of the times this message was delivered to clients. | long | |
CamelAzureServiceBusEnqueuedSequenceNumber (consumer) Constant: | Gets the enqueued sequence number assigned to a message by Service Bus. | long | |
CamelAzureServiceBusEnqueuedTime (consumer) Constant: | Gets the datetime at which this message was enqueued in Azure Service Bus. | OffsetDateTime | |
CamelAzureServiceBusExpiresAt (consumer) Constant: | Gets the datetime at which this message will expire. | OffsetDateTime | |
CamelAzureServiceBusLockToken (consumer) Constant: | Gets the lock token for the current message. | String | |
CamelAzureServiceBusLockedUntil (consumer) Constant: | Gets the datetime at which the lock of this message expires. | OffsetDateTime | |
CamelAzureServiceBusMessageId (consumer) Constant: | Gets the identifier for the message. | String | |
CamelAzureServiceBusPartitionKey (consumer) Constant: | Gets the partition key for sending a message to a partitioned entity. | String | |
CamelAzureServiceBusRawAmqpMessage (consumer) Constant: | The representation of message as defined by AMQP protocol. | AmqpAnnotatedMessage | |
CamelAzureServiceBusReplyTo (consumer) Constant: | Gets the address of an entity to send replies to. | String | |
CamelAzureServiceBusReplyToSessionId (consumer) Constant: | Gets or sets a session identifier augmenting the ReplyTo address. | String | |
CamelAzureServiceBusSequenceNumber (consumer) Constant: | Gets the unique number assigned to a message by Service Bus. | long | |
CamelAzureServiceBusSessionId (consumer) Constant: | Gets the session id of the message. | String | |
CamelAzureServiceBusSubject (consumer) Constant: | Gets the subject for the message. | String | |
CamelAzureServiceBusTimeToLive (consumer) Constant: | Gets the duration before this message expires. | Duration | |
CamelAzureServiceBusTo (consumer) Constant: | Gets the to address. | String | |
CamelAzureServiceBusScheduledEnqueueTime (common) Constant: | (producer)Overrides the OffsetDateTime at which the message should appear in the Service Bus queue or topic. (consumer) Gets the scheduled enqueue time of this message. | OffsetDateTime | |
CamelAzureServiceBusServiceBusTransactionContext (producer) Constant: | Overrides the transaction in service. This object just contains transaction id. | ServiceBusTransactionContext | |
CamelAzureServiceBusProducerOperation (producer) Constant: | Overrides the desired operation to be used in the producer. Enum values:
| ServiceBusProducerOperationDefinition | |
CamelAzureServiceBusCorrelationId (common) Constant: | Gets or Sets a correlation identifier. | String |
Usage
Authentication Information
You have three different Credential Types: AZURE_IDENTITY, TOKEN_CREDENTIAL and CONNECTION_STRING. You can also provide a client instance yourself. To use this component, you have three options to provide the required Azure authentication information:
CONNECTION_STRING:
-
Provide
connectionString
string it is the simplest option to get started.
TOKEN_CREDENTIAL:
-
Provide an implementation of
com.azure.core.credential.TokenCredential
into the Camel’s Registry, e.g., using thecom.azure.identity.DefaultAzureCredentialBuilder().build();
API. See the documentation here about Azure-AD authentication.
AZURE_IDENTITY:
-
This will use
com.azure.identity.DefaultAzureCredentialBuilder().build();
instance. This will follow the Default Azure Credential Chain. See the documentation here about Azure-AD authentication.
Client instance:
-
You can provide a
com.azure.messaging.servicebus.ServiceBusSenderClient
for sending message and/orcom.azure.messaging.servicebus.ServiceBusReceiverClient
to receive messages. If you provide the instances, they will be autowired.
Message Body
In the producer, this component accepts message body of String
, byte[]
and BinaryData
types or List<String>
, List<byte[]>
and List<BinaryData>
to send batch messages.
In the consumer, the returned message body will be of type `String.
Azure ServiceBus Producer operations
Operation | Description |
---|---|
| Sends a set of messages to a Service Bus queue or topic using a batched approach. |
| Sends a scheduled message to the Azure Service Bus entity this sender is connected to. A scheduled message is enqueued and made available to receivers only at the scheduled enqueue time. |
Examples
-
sendMessages
from("direct:start")
.process(exchange -> {
final List<Object> inputBatch = new LinkedList<>();
inputBatch.add("test batch 1");
inputBatch.add("test batch 2");
inputBatch.add("test batch 3");
inputBatch.add(123456);
exchange.getIn().setBody(inputBatch);
})
.to("azure-servicebus:test//?connectionString=test")
.to("mock:result");
-
scheduleMessages
from("direct:start")
.process(exchange -> {
final List<Object> inputBatch = new LinkedList<>();
inputBatch.add("test batch 1");
inputBatch.add("test batch 2");
inputBatch.add("test batch 3");
inputBatch.add(123456);
exchange.getIn().setHeader(ServiceBusConstants.SCHEDULED_ENQUEUE_TIME, OffsetDateTime.now());
exchange.getIn().setBody(inputBatch);
})
.to("azure-servicebus:test//?connectionString=test&producerOperation=scheduleMessages")
.to("mock:result");
-
receiveMessages
from("azure-servicebus:test//?connectionString=test")
.log("${body}")
.to("mock:result");
Spring Boot Auto-Configuration
When using azure-servicebus 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-azure-servicebus-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 28 options, which are listed below.