SLF4J Channel Adapter

The slf4j adapter is a sink that logs the message payload through the SLF4J API. It is useful for debugging, auditing, and logging intermediate outputs.

Availability

The slf4j-channel-adapter module, a transitive dependency of pipelite-core.

Usage as sink

The adapter only writes: a flow that reads from it (fromSource("slf4j://…")) fails when the context starts, saying the endpoint "cannot be used as a source".

.toSink("slf4j://my-logger")

The Slf4jProducer logs the output Exchange payload at INFO level using the logger named after the URL.

URL format

slf4j://<logger-name>

Parameter Description

Parameter	Description
`logger-name`	SLF4J logger name (e.g. `my-logger` → `LoggerFactory.getLogger("my-logger")`)

logger-name

SLF4J logger name (e.g. my-logger → LoggerFactory.getLogger("my-logger"))

Usage in WireTap

The SLF4J adapter is particularly useful as a WireTap destination for audit logging:

.wireTap("audit-tap", "slf4j://audit-logger")
.toSink("kafka://output-topic")

In this case the Exchange is logged by SLF4J while simultaneously being sent to Kafka.

The slf4j adapter is exclusively a sink: it does not support use as a flow source.