Github user trkurc commented on a diff in the pull request:
https://github.com/apache/nifi/pull/271#discussion_r56103351
--- Diff:
nifi-nar-bundles/nifi-spring-bundle/nifi-spring-processors/src/main/resources/docs/org.apache.nifi.spring.SpringContextProcessor/additionalDetails.html
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+<!DOCTYPE html>
+<html lang="en">
+ <!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version
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+ (the "License"); you may not use this file except in compliance with
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+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
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+ <head>
+ <meta charset="utf-8" />
+ <title>SpringContextProcessor</title>
+ <link rel="stylesheet" href="../../css/component-usage.css"
type="text/css" />
+ </head>
+
+ <body>
+ <!-- Processor Documentation
================================================== -->
+ <h2>Description:</h2>
+ <p>
+ <b>SpringContextProcessor</b> â allows integration of
processes encapsulated in Spring Application Context to run as NiFi
+ processor by becoming a runtime host for an instance of Spring
Application Context.
+ </p>
+ <p>
+ Communication between NiFi and process encapsulated within
Spring Application Context is accomplished via Spring Messaging
+ (one of the core modules of Spring Framework) and supports 3
usage modes:
+ <ul>
+ <li><i>Headless</i> - no interaction with NiFi, meaning
nothing is sent to it and nothing is received from it (i.e., some monitoring
app).
+ In this case NiFi simply plays the role of the runtime
host.</li>
+ <li><i>One way (NiFi -> Spring or Spring ->
NiFi). </i> - This depends on existence of pre-defined message channel in
Spring
+ Application Context. The name of the channel should be
âfromNiFiâ and the type
<i>org.springframework.messaging.MessageChannel.</i></li>
+ <li><i>By-directional (NiFi -> Spring -> Nifi or
Spring -> NiFi -> Spring)</i> - This depends on existence of two channels
+ in Spring Application Context. One channel receives
messages from NiFi with name âfromNiFiâ and type
<i>org.springframework.messaging.MessageChannel</i>i>
+ and another is o receive messages from Spring with
name âtoNiFiâ and type
<i>org.springframework.messaging.PollableChannel.</i></li>
+ </ul>
+ The example below demonstrates template configuration for
bi-directional Spring Application Context configuration:
+ <code>
+ <pre>
+ <int:channel id=âfromNiFiâ/>
+
+ <!â
+ your custom app configuration to receive messages from âfromNiFiâ
channel and optionally send back to NiFi via âtoNiFiâ channel.
+ It could contain any Spring-based application (i.e., Spring
Integration, Apache Camel and/or custom code). All you need to do is inject
+ channels into your beans and send/receive messages from it.
+ -->
+
+ <int:channel id="toNiFi">
+ <int:queue/>
+ </int:channel>
+ </pre>
+ </code>
+ </p>
+ <p>
+ The component is based on assumption that user has an existing
Spring Application encapsulated in Spring Context that exposes optional in/out
+ MessagingChannels to allow data to flow to/from ApplicationContext
and into/out-of. NiFi.
+ Such application is realized by having a directory on the file
system, which contains contains all required resources for such application to
run.
+ Such resources usually are JAR files to satisfy application's
class-path as well as JAR representing the application and its configuration.
+ Below is the example of what such directory may contain. In this
case the 'SI_DEMO-0.0.1-SNAPSHOT.jar' represents the actual application and the
rest
+ of the JARs represent class-path dependency required by an
application.
+ <pre>
+ deps
+ âââ SI_DEMO-0.0.1-SNAPSHOT.jar
+ âââ aopalliance-1.0.jar
+ âââ commons-logging-1.2.jar
+ âââ spring-aop-4.2.4.RELEASE.jar
+ âââ spring-beans-4.2.4.RELEASE.jar
+ âââ spring-context-4.2.4.RELEASE.jar
+ âââ spring-core-4.2.4.RELEASE.jar
+ âââ spring-expression-4.2.4.RELEASE.jar
+ âââ spring-integration-core-4.2.5.RELEASE.jar
+ âââ spring-messaging-4.2.4.RELEASE.jar
+ </pre>
+ </p>
+ <p>
+ You introduce the processor the usual way and then configure its
properties:
+ <ul>
+ <li><i><b>Application Context config path</b></i> [REQUIRED] - a
path to the Application Context configuration.
+ The path is relative to the class-path of the application defined
by the <i>Application Context class path</i> property </li>
+ <li><i><b>Application Context class path</b></i> [REQUIRED] - a
path to a directory on the file system where application dependencies are. </li>
+ <li><i>Send Timeout</i> [OPTIONAL] - the wait time for sending
messages to Spring Application Context. Only required if NiFi plans to send
data o Spring.
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Typo: s/ o / to /
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