pekko/akka-camel/src/main/scala/akka/camel/CamelMessage.scala

293 lines
13 KiB
Scala

/**
* Copyright (C) 2009-2016 Typesafe Inc. <http://www.typesafe.com>
*/
package akka.camel
import java.util.{ Map JMap, Set JSet }
import javax.activation.DataHandler
import org.apache.camel.{ CamelContext, Message JCamelMessage, StreamCache }
import akka.AkkaException
import scala.reflect.ClassTag
import scala.runtime.ScalaRunTime
import scala.util.Try
import scala.collection.JavaConversions._
import akka.dispatch.Mapper
/**
* An immutable representation of a Camel message.
*/
class CamelMessage(val body: Any, val headers: Map[String, Any], val attachments: Map[String, DataHandler]) extends Serializable with Product {
def this(body: Any, headers: JMap[String, Any]) = this(body, headers.toMap, Map.empty[String, DataHandler]) //Java
def this(body: Any, headers: JMap[String, Any], attachments: JMap[String, DataHandler]) = this(body, headers.toMap, attachments.toMap) //Java
def this(body: Any, headers: Map[String, Any]) = this(body, headers.toMap, Map.empty[String, DataHandler])
def copy(body: Any = this.body, headers: Map[String, Any] = this.headers): CamelMessage = CamelMessage(body, headers, this.attachments)
override def toString: String = "CamelMessage(%s, %s, %s)" format (body, headers, attachments)
/**
* Returns those headers from this message whose name is contained in <code>names</code>.
*/
def headers(names: Set[String]): Map[String, Any] = headers filterKeys names
/**
* Java API: Returns those headers from this message whose name is contained in <code>names</code>.
* The returned headers map is backed up by an immutable headers map. Any attempt to modify
* the returned map will throw an exception.
*/
def getHeaders(names: JSet[String]): JMap[String, Any] = headers(names.toSet)
/**
* Java API: Returns all headers from this message. The returned headers map is backed up by this
* message's immutable headers map. Any attempt to modify the returned map will throw an
* exception.
*/
def getHeaders: JMap[String, Any] = headers
/**
* Java API: Creates a new CamelMessage with given <code>headers</code>. A copy of the headers map is made.
*/
def withHeaders[A](headers: JMap[String, A]): CamelMessage = copy(this.body, headers.toMap)
/**
* Returns the header by given <code>name</code> parameter in a [[scala.util.Try]]. The header is converted to type <code>T</code>, which is returned
* in a [[scala.util.Success]]. If an exception occurs during the conversion to the type <code>T</code> or when the header cannot be found,
* the exception is returned in a [[scala.util.Failure]].
*
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*
*/
def headerAs[T](name: String)(implicit t: ClassTag[T], camelContext: CamelContext): Try[T] =
Try(headers.get(name).map(camelContext.getTypeConverter.mandatoryConvertTo[T](t.runtimeClass.asInstanceOf[Class[T]], _)).getOrElse(throw new NoSuchElementException(name)))
/**
* Java API: Returns the header by given <code>name</code> parameter. The header is converted to type <code>T</code> as defined by the <code>clazz</code> parameter.
* An exception is thrown when the conversion to the type <code>T</code> fails or when the header cannot be found.
*
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*/
def getHeaderAs[T](name: String, clazz: Class[T], camelContext: CamelContext): T = headerAs[T](name)(ClassTag(clazz), camelContext).get
/**
* Returns a new CamelMessage with a transformed body using a <code>transformer</code> function.
* This method will throw a [[java.lang.ClassCastException]] if the body cannot be mapped to type A.
*/
def mapBody[A, B](transformer: A B): CamelMessage = copy(body = transformer(body.asInstanceOf[A]))
/**
* Java API: Returns a new CamelMessage with a transformed body using a <code>transformer</code> function.
* This method will throw a [[java.lang.ClassCastException]] if the body cannot be mapped to type A.
*/
def mapBody[A, B](transformer: Mapper[A, B]): CamelMessage = copy(body = transformer(body.asInstanceOf[A]))
/**
* Returns the body of the message converted to the type <code>T</code>. Conversion is done
* using Camel's type converter. The type converter is obtained from the CamelContext that is passed in.
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*/
def bodyAs[T](implicit t: ClassTag[T], camelContext: CamelContext): T = getBodyAs(t.runtimeClass.asInstanceOf[Class[T]], camelContext)
/**
* Java API: Returns the body of the message converted to the type as given by the <code>clazz</code>
* parameter. Conversion is done using Camel's type converter. The type converter is obtained
* from the CamelContext that is passed in.
* <p>
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*/
def getBodyAs[T](clazz: Class[T], camelContext: CamelContext): T = {
val result = camelContext.getTypeConverter.mandatoryConvertTo[T](clazz, body)
// to be able to re-read a StreamCache we must "undo" the side effect by resetting the StreamCache
resetStreamCache()
result
}
/**
* Reset StreamCache body. Nothing is done if the body is not a StreamCache.
* See http://camel.apache.org/stream-caching.html
*/
def resetStreamCache(): Unit = body match {
case stream: StreamCache stream.reset
case _
}
/**
* Java API: Returns a new CamelMessage with a new body, while keeping the same headers.
*/
def withBody[T](body: T): CamelMessage = copy(body = body)
/**
* Creates a CamelMessage with current <code>body</code> converted to type <code>T</code>.
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*/
def withBodyAs[T](implicit t: ClassTag[T], camelContext: CamelContext): CamelMessage = withBodyAs(t.runtimeClass.asInstanceOf[Class[T]])
/**
* Java API: Creates a CamelMessage with current <code>body</code> converted to type <code>clazz</code>.
* <p>
* The CamelContext is accessible in a [[akka.camel.javaapi.UntypedConsumerActor]] and [[akka.camel.javaapi.UntypedProducerActor]]
* using the `getCamelContext` method, and is available on the [[akka.camel.CamelExtension]].
*/
def withBodyAs[T](clazz: Class[T])(implicit camelContext: CamelContext): CamelMessage = copy(body = getBodyAs(clazz, camelContext))
/**
* Returns those attachments from this message whose name is contained in <code>names</code>.
*/
def attachments(names: Set[String]): Map[String, DataHandler] = attachments filterKeys names
/**
* Java API: Returns those attachments from this message whose name is contained in <code>names</code>.
* The returned headers map is backed up by an immutable headers map. Any attempt to modify
* the returned map will throw an exception.
*/
def getAttachments(names: JSet[String]): JMap[String, DataHandler] = attachments(names.toSet)
/**
* Java API: Returns all attachments from this message. The returned attachments map is backed up by this
* message's immutable headers map. Any attempt to modify the returned map will throw an
* exception.
*/
def getAttachments: JMap[String, DataHandler] = attachments
/**
* Java API: Creates a new CamelMessage with given <code>attachments</code>. A copy of the attachments map is made.
*/
def withAttachments(attachments: JMap[String, DataHandler]): CamelMessage = CamelMessage(this.body, this.headers, attachments.toMap)
/**
* SCALA API: Creates a new CamelMessage with given <code>attachments</code>.
*/
def withAttachments(attachments: Map[String, DataHandler]): CamelMessage = CamelMessage(this.body, this.headers, attachments)
/**
* Indicates whether some other object is "equal to" this one.
*/
override def equals(that: Any): Boolean =
that match {
case that: CamelMessage if canEqual(that)
this.body == that.body &&
this.headers == that.headers &&
this.attachments == that.attachments
case _ false
}
/**
* Returns a hash code value for the object.
*/
override def hashCode(): Int = ScalaRunTime._hashCode(this)
/**
* Returns the n-th element of this product, 0-based.
*/
override def productElement(n: Int): Any = n match {
case 0 body
case 1 headers
case 2 attachments
}
/**
* Returns the size of this product.
*/
override def productArity: Int = 3
/**
* Indicates if some other object can be compared (based on type).
* This method should be called from every well-designed equals method that is open to be overridden in a subclass.
*/
override def canEqual(that: Any): Boolean = that match {
case _: CamelMessage true
case _ false
}
}
/**
* Companion object of CamelMessage class.
*/
object CamelMessage extends ((Any, Map[String, Any]) CamelMessage) {
/**
* Returns a new CamelMessage based on the <code>body</code> and <code>headers</code>.
*/
def apply(body: Any, headers: Map[String, Any]): CamelMessage = new CamelMessage(body, headers, Map.empty[String, DataHandler])
/**
* Returns a new CamelMessage based on the <code>body</code>, <code>headers</code> and <code>attachments</code>.
*/
def apply(body: Any, headers: Map[String, Any], attachments: Map[String, DataHandler]): CamelMessage = new CamelMessage(body, headers, attachments)
/**
* Returns <code>Some(body, headers)</code>.
*/
def unapply(camelMessage: CamelMessage): Option[(Any, Map[String, Any])] = Some((camelMessage.body, camelMessage.headers))
/**
* CamelMessage header to correlate request with response messages. Applications that send
* messages to a Producer actor may want to set this header on the request message
* so that it can be correlated with an asynchronous response. Messages send to Consumer
* actors have this header already set.
*/
val MessageExchangeId = "MessageExchangeId" //Deliberately without type ascription to make it a constant
/**
* Creates a canonical form of the given message <code>msg</code>. If <code>msg</code> of type
* CamelMessage then <code>msg</code> is returned, otherwise <code>msg</code> is set as body of a
* newly created CamelMessage object.
*/
private[camel] def canonicalize(msg: Any) = msg match {
case mobj: CamelMessage mobj
case body CamelMessage(body, Map.empty[String, Any])
}
/**
* Creates a new CamelMessage object from the Camel message.
*
* @param headers additional headers to set on the created CamelMessage in addition to those
* in the Camel message.
*/
private[camel] def from(camelMessage: JCamelMessage, headers: Map[String, Any]): CamelMessage =
CamelMessage(camelMessage.getBody, headers ++ camelMessage.getHeaders, camelMessage.getAttachments.toMap)
/**
* Creates a new CamelMessageWithAttachments object from the Camel message.
*
* @param headers additional headers to set on the created CamelMessageWithAttachments in addition to those
* in the Camel message.
* @param attachments additional attachments to set on the created CamelMessageWithAttachments in addition to those
* in the Camel message.
*/
private[camel] def from(camelMessage: JCamelMessage, headers: Map[String, Any], attachments: Map[String, DataHandler]): CamelMessage =
CamelMessage(camelMessage.getBody, headers ++ camelMessage.getHeaders, attachments ++ camelMessage.getAttachments)
/**
* INTERNAL API
* copies the content of this CamelMessageWithAttachments to an Apache Camel Message.
*/
private[camel] def copyContent(from: CamelMessage, to: JCamelMessage): Unit = {
to.setBody(from.body)
for ((name, value) from.headers) to.getHeaders.put(name, value.asInstanceOf[AnyRef])
to.getAttachments.putAll(from.getAttachments)
}
}
/**
* Positive acknowledgement message (used for application-acknowledged message receipts).
* When `autoAck` is set to false in the [[akka.camel.Consumer]], you can send an `Ack` to the sender of the CamelMessage.
*/
case object Ack {
/** Java API to get the Ack singleton */
def getInstance = this
}
/**
* An exception indicating that the exchange to the camel endpoint failed.
* It contains the failure cause obtained from Exchange.getException and the headers from either the Exchange.getIn
* message or Exchange.getOut message, depending on the exchange pattern.
*/
class AkkaCamelException private[akka] (cause: Throwable, val headers: Map[String, Any])
extends AkkaException(cause.getMessage, cause) {
def this(cause: Throwable) = this(cause, Map.empty)
}