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HTTP Connector

The HTTP connector sends and receives HTTP or HTTPS requests using a host, port, and address. Find the two important use cases for this component below.

Depending on your needs, you can either:

  • Use the connector as an HTTP Listener Connector for requests that arrive at a certain address, subsequently generating an HTTP response

  • Use the connector as an HTTP Request Connector to send requests to a certain address and receive the returned response

Through additional configuration, the connector allows you to:

  • Use TLS encryption to send or receive HTTPS requests.

  • Send Authenticated Requests using Basic Authentication, Digest, or OAuth.

In Mule 3.6 and later versions, the HTTP and HTTPS endpoint-based connectors and transports have been replaced by a single HTTP operation-based connector which supports HTTPS.

Using HTTP Connectors

The HTTP connector can work in one of two ways, depending on where it is placed in a flow:

Quick References

Use the HTTP Listener or HTTP Request quick reference for your editing environment: Studio or XML Editor.

HTTP Listener Quick Reference for Studio

To instantiate the connector as an HTTP listener, place it onto a blank Anypoint Studio canvas into the Source section of a new flow (the first element in the flow):

show source and process section of flow
Figure 1. New Flow Showing Source and Process Phases
drag to source
Figure 2. Drag the HTTP Connector to the Source Side
http listener in source
Figure 3. See the Connector Populate the Source Side

HTTP Request Quick Reference for Studio

To instantiate the connector as an HTTP request connector, you must place it into the Process section of a flow (anywhere except the first element in the flow).

drag to process
Figure 4. Drag the HTTP Connector to the Process Side
http request conn in process side
Figure 5. Flow Showing HTTP Connector in Process Side

HTTP Listener Quick Reference for XML Editor

To instantiate the connector as an HTTP Listener Connector, add the following XML tag at the start of a flow:

<http:listener config-ref="HTTP_Listener_Configuration" path="/" />

This element must reference a global configuration element of the following type:

<http:listener-config name="HTTP_Listener_Configuration" host="localhost" port="8081" />

HTTP Request Quick Reference for XML Editor

To instantiate the connector as an HTTP Request Connector, add the following XML tag in any part of a flow:

<http:request config-ref="HTTP_Request_Configuration" path="/" method="GET" />

This element must reference a global configuration element of the following type:

<http:request-config name="HTTP_Request_Configuration" host="example.com" port="8081"/>
  • To migrate a project that uses the old HTTP endpoint-based connector to the new HTTP operation-based connector, see Migrating to the New HTTP Connector. The old HTTP endpoint-based connector still works with Mule runtime 3.6, but it’s deprecated and will eventually be removed.

  • You can edit the log4j2 configuration file to make the logging of the HTTP connector’s activity a lot more verbose, if you need to. See Logging in Mule for instructions.

Debugging with Mule Logs

Gaining visibility into HTTP inbound and outbound behavior can be achieved by enabling underlying library loggers with log4j2. If you have never adjusted Mule logging levels in the past, read configuring custom logging settings before continuing.

Logging Listener and Request Activity

When you select the DEBUG level on org.mule.module.http.internal.HttpMessageLogger, activity coming from all HTTP Listeners and HTTP Requests is logged. This includes the HTTP Listener’s inbound request, HTTP Request’s outbound request, and each response body.

HTTP Listener Log Output

The log output of the HTTP Listener displays the metadata of the inbound request.

DEBUG 2016-02-10 10:55:03,234 [[hello].HTTP_Listener_Configuration.worker.01] org.mule.module.http.internal.HttpMessageLogger: LISTENER
GET / HTTP/1.1
Host: localhost:8081
User-Agent: curl/7.43.0
Accept: */*

The log output also displays information about the response being sent back.

LISTENER
HTTP/1.1 200
Transfer-Encoding: chunked
Content-Type: application/json; charset=UTF-8
Date: Wed, 10 Feb 2016 18:55:03 GMT

2000
{
  "message" : "hello, world"
}
Chunked encoding produces a separate log record for each chunk.

HTTP Request Log Output

The log output of the HTTP Request displays metadata of the outbound request.

DEBUG 2016-02-10 11:29:18,647 [[hello].http.requester.HTTP_Request_Configuration(1) SelectorRunner] org.mule.module.http.internal.HttpMessageLogger: REQUESTER
GET /v3/hello HTTP/1.1
Host: mocker-server.cloudhub.io:80
User-Agent: AHC/1.0
Connection: keep-alive
Accept: */*

The log output also displays information about the response sent back from the target.

DEBUG 2016-02-10 11:29:18,729 [[hello].http.requester.HTTP_Request_Configuration.worker(1)] org.mule.module.http.internal.HttpMessageLogger: REQUESTER
HTTP/1.1 200
Content-Type: application/json
Date: Wed, 10 Feb 2016 19:29:18 GMT
Server: nginx
Content-Length: 10940
Connection: keep-alive

{
  "message" : "Hello, world"
}

Logging Packet Metadata

If you wish to log the actual request and response packets transmitted over HTTP, enable the DEBUG level on com.ning.http.client.providers.grizzly. Once set, the log reports metadata of the request packets from AsyncHTTPClientFilter and the response packets from AhcEventFilter. Unlike the HttpMessageLogger, this setting does not log request or response bodies.

Request Packet Log Output

Example of the log output of the request packet’s metadata:

DEBUG 2016-02-10 11:16:29,421 [[hello].http.requester.HTTP_Request_Configuration(1) SelectorRunner] com.ning.http.client.providers.grizzly.AsyncHttpClientFilter: REQUEST: HttpRequestPacket (
   method=GET
   url=/v3/hello
   query=null
   protocol=HTTP/1.1
   content-length=-1
   headers=[
      Host=mocker-server.cloudhub.io:80
      User-Agent=AHC/1.0
      Connection=keep-alive
      Accept=*/*]
)

Response Packet Log Output

Example of the log output of the response packet’s metadata:

DEBUG 2016-02-10 11:16:29,508 [[hello].http.requester.HTTP_Request_Configuration.worker(1)] com.ning.http.client.providers.grizzly.AhcEventFilter: RESPONSE: HttpResponsePacket (
  status=200
  reason=
  protocol=HTTP/1.1
  content-length=10940
  committed=false
  headers=[
      content-type=application/json
      date=Wed, 10 Feb 2016 19:16:29 GMT
      server=nginx
      content-length=10940
      connection=keep-alive]
)

Non-blocking Processing

The HTTP Connector (both the HTTP Listener and the HTTP Request connector) can be used with a non-blocking processing strategy. With this strategy, while a message is waiting for a response from an external source, the message processor is still free to process other messages that arrive.

Note that not all Mule components currently support the non-blocking processing strategy. If there are any unsupported components in a flow, they cause the flow to fall back to synchronous processing.

See Also