java.lang.Object
- org.springframework.cloud.sleuth.instrument.messaging.MessagingSleuthOperators

```
public final class MessagingSleuthOperators
extends Object
```
Messaging helpers to manually parse and inject spans. We're treating message headers as a context that gets passed through. IMPORTANT: This API is experimental and might change in the future. The forInputMessage factory methods will retrieve the tracer context from the message headers and set up a a child span in the header under key Span.class name. If you need to continue it or tag it, it's enough to retrieve it from the headers. The first messaging span (the one that was first found in the input message) is present under the traceHandlerParentSpan header key.

Since:

3.0.0

Author:

Marcin Grzejszczak

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static <T> org.springframework.messaging.Message<T>`	`afterMessageHandled(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Throwable ex)`	Reports the span stored in the message.
`static <T> Function<org.springframework.messaging.Message<T>,org.springframework.messaging.Message<T>>`	`asFunction(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> inputMessage)`	Function converting an input message to a message with tracer headers.
`static <T> org.springframework.messaging.Message<T>`	`forInputMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message)`	Processes the input message and returns a message with a header containing a span.
`static <T> org.springframework.messaging.Message<T>`	`forInputMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Consumer<org.springframework.messaging.Message<T>> withSpanInScope)`	Executes a span wrapped operation for an input message.
`static <T> org.springframework.messaging.Message<T>`	`handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message)`	Creates an output message with tracer headers and reports the corresponding producer span.
`static <T> org.springframework.messaging.Message<T>`	`handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Throwable throwable)`	Creates an output message with tracer headers and reports the corresponding producer span.
`static <T> org.springframework.messaging.Message<T>`	`handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Consumer<Span> spanCustomizer, Throwable throwable)`	Creates an output message with tracer headers and reports the corresponding producer span.
`static <T> Span`	`spanFromMessage(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message)`	Retrieves tracer information from message headers.
`static <T> void`	`withSpanInScope(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Consumer<org.springframework.messaging.Message<T>> withSpanInScope)`	Retrieves tracer information from message headers and applies the operation.
`static <T> org.springframework.messaging.Message<T>`	`withSpanInScope(org.springframework.beans.factory.BeanFactory beanFactory, org.springframework.messaging.Message<T> message, Function<org.springframework.messaging.Message<T>,org.springframework.messaging.Message<T>> withSpanInScope)`	Retrieves tracer information from message headers and applies the operation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

forInputMessage

public static <T> org.springframework.messaging.Message<T> forInputMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                           org.springframework.messaging.Message<T> message,
                                                                           Consumer<org.springframework.messaging.Message<T>> withSpanInScope)

Executes a span wrapped operation for an input message.

Type Parameters:: T - - type of payload
Parameters:: beanFactory - - bean factory; message - - message to wrap; withSpanInScope - - an operation that will be wrapped in a span and the span will be reported at the end
Returns:: message with tracer context

forInputMessage

public static <T> org.springframework.messaging.Message<T> forInputMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                           org.springframework.messaging.Message<T> message)

Processes the input message and returns a message with a header containing a span.

Type Parameters:: T - - payload type
Parameters:: beanFactory - - bean factory; message - - input message to process
Returns:: message with tracer context

asFunction

public static <T> Function<org.springframework.messaging.Message<T>,org.springframework.messaging.Message<T>> asFunction(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                                                                               org.springframework.messaging.Message<T> inputMessage)

Function converting an input message to a message with tracer headers.

Type Parameters:: T - input message type
Parameters:: beanFactory - - bean factory; inputMessage - - input message to process
Returns:: function representation of input message with tracer context

spanFromMessage
```
public static <T> Span spanFromMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                       org.springframework.messaging.Message<T> message)
```
Retrieves tracer information from message headers.

Type Parameters:

T - - payload type

Parameters:

beanFactory - - bean factory

message - - message to process

Returns:

span retrieved from message or null if there was no span

withSpanInScope

public static <T> void withSpanInScope(org.springframework.beans.factory.BeanFactory beanFactory,
                                       org.springframework.messaging.Message<T> message,
                                       Consumer<org.springframework.messaging.Message<T>> withSpanInScope)

Retrieves tracer information from message headers and applies the operation.

Type Parameters:: T - - payload type
Parameters:: beanFactory - - bean factory; message - - message to process; withSpanInScope - - an operation that will be wrapped in a span but will not be reported

withSpanInScope

public static <T> org.springframework.messaging.Message<T> withSpanInScope(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                           org.springframework.messaging.Message<T> message,
                                                                           Function<org.springframework.messaging.Message<T>,org.springframework.messaging.Message<T>> withSpanInScope)

Retrieves tracer information from message headers and applies the operation.

Type Parameters:: T - - payload type
Parameters:: beanFactory - - bean factory; message - - message to process; withSpanInScope - - an operation that will be wrapped in a span but will not be reported
Returns:: a message with tracer headers.

handleOutputMessage
```
public static <T> org.springframework.messaging.Message<T> handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                               org.springframework.messaging.Message<T> message)
```
Creates an output message with tracer headers and reports the corresponding producer span. If the message contains a header called destination it will be used to tag the span with destination name.

Type Parameters:

T - - message payload

Parameters:

beanFactory - - bean factory

message - - message to which tracer headers should be injected

Returns:

instrumented message

handleOutputMessage

public static <T> org.springframework.messaging.Message<T> handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                               org.springframework.messaging.Message<T> message,
                                                                               Throwable throwable)

Creates an output message with tracer headers and reports the corresponding producer span. If the message contains a header called destination it will be used to tag the span with destination name.

Type Parameters:: T - - message payload
Parameters:: beanFactory - - bean factory; message - - message to which tracer headers should be injected; throwable - - exception that took place while processing the message
Returns:: instrumented message

handleOutputMessage

public static <T> org.springframework.messaging.Message<T> handleOutputMessage(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                               org.springframework.messaging.Message<T> message,
                                                                               Consumer<Span> spanCustomizer,
                                                                               Throwable throwable)

Creates an output message with tracer headers and reports the corresponding producer span. If the message contains a header called destination it will be used to tag the span with destination name.

Type Parameters:: T - - message payload
Parameters:: beanFactory - - bean factory; message - - message to which tracer headers should be injected; spanCustomizer - - customizer of the output span; throwable - - exception that took place while processing the message
Returns:: instrumented message

afterMessageHandled

public static <T> org.springframework.messaging.Message<T> afterMessageHandled(org.springframework.beans.factory.BeanFactory beanFactory,
                                                                               org.springframework.messaging.Message<T> message,
                                                                               Throwable ex)

Reports the span stored in the message.

Type Parameters:: T - - message payload
Parameters:: beanFactory - - bean factory; message - - message with tracer context; ex - - potential exception that took place while processing
Returns:: instrumented message

Class MessagingSleuthOperators

Method Summary

Methods inherited from class java.lang.Object

Method Detail

forInputMessage

forInputMessage

asFunction

spanFromMessage

withSpanInScope

withSpanInScope

handleOutputMessage

handleOutputMessage

handleOutputMessage

afterMessageHandled