27 lines
5.9 KiB
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27 lines
5.9 KiB
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<title>1. Introduction</title><link rel="stylesheet" type="text/css" href="css/manual-multipage.css"><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="multi_spring-cloud-function.html" title="Spring Cloud Function"><link rel="up" href="multi_spring-cloud-function.html" title="Spring Cloud Function"><link rel="prev" href="multi_pr01.html" title=""><link rel="next" href="multi__getting_started.html" title="2. Getting Started"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">1. Introduction</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="multi_pr01.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="multi__getting_started.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="_introduction" href="#_introduction"></a>1. Introduction</h1></div></div></div><p>Spring Cloud Function is a project with the following high-level goals:</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">Promote the implementation of business logic via functions.</li><li class="listitem">Decouple the development lifecycle of business logic from any specific runtime target so that the same code can run as a web endpoint, a stream processor, or a task.</li><li class="listitem">Support a uniform programming model across serverless providers, as well as the ability to run standalone (locally or in a PaaS).</li><li class="listitem">Enable Spring Boot features (auto-configuration, dependency injection, metrics) on serverless providers.</li></ul></div><p>It abstracts away all of the transport details and
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infrastructure, allowing the developer to keep all the familiar tools
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and processes, and focus firmly on business logic.</p><p>Here’s a complete, executable, testable Spring Boot application
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(implementing a simple string manipulation):</p><pre class="programlisting"><em><span class="hl-annotation" style="color: gray">@SpringBootApplication</span></em>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span> Application {
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<em><span class="hl-annotation" style="color: gray">@Bean</span></em>
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> Function<Flux<String>, Flux<String>> uppercase() {
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">return</span> flux -> flux.map(value -> value.toUpperCase());
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}
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<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">public</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">static</span> <span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">void</span> main(String[] args) {
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SpringApplication.run(Application.<span xmlns:d="http://docbook.org/ns/docbook" class="hl-keyword">class</span>, args);
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}
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}</pre><p>It’s just a Spring Boot application, so it can be built, run and
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tested, locally and in a CI build, the same way as any other Spring
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Boot application. The <code class="literal">Function</code> is from <code class="literal">java.util</code> and <code class="literal">Flux</code> is a
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<a class="link" href="http://www.reactive-streams.org/" target="_top">Reactive Streams</a> <code class="literal">Publisher</code> from
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<a class="link" href="https://projectreactor.io/" target="_top">Project Reactor</a>. The function can be
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accessed over HTTP or messaging.</p><p>Spring Cloud Function has 4 main features:</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">Wrappers for <code class="literal">@Beans</code> of type <code class="literal">Function</code>, <code class="literal">Consumer</code> and
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<code class="literal">Supplier</code>, exposing them to the outside world as either HTTP
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endpoints and/or message stream listeners/publishers with RabbitMQ, Kafka etc.</li><li class="listitem">Compiling strings which are Java function bodies into bytecode, and
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then turning them into <code class="literal">@Beans</code> that can be wrapped as above.</li><li class="listitem">Deploying a JAR file containing such an application context with an
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isolated classloader, so that you can pack them together in a single
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JVM.</li><li class="listitem">Adapters for <a class="link" href="https://github.com/spring-cloud/spring-cloud-function/tree/master/spring-cloud-function-adapters/spring-cloud-function-adapter-aws" target="_top">AWS Lambda</a>, <a class="link" href="https://github.com/spring-cloud/spring-cloud-function/tree/master/spring-cloud-function-adapters/spring-cloud-function-adapter-azure" target="_top">Azure</a>, <a class="link" href="https://github.com/spring-cloud/spring-cloud-function/tree/master/spring-cloud-function-adapters/spring-cloud-function-adapter-openwhisk" target="_top">Apache OpenWhisk</a> and possibly other "serverless" service providers.</li></ol></div><p>Unresolved directive in spring-cloud-function.adoc - include::https://raw.githubusercontent.com/spring-cloud/spring-cloud-build/master/docs/src/main/asciidoc/contributing-docs.adoc[]</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="multi_pr01.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="multi__getting_started.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"> </td><td width="20%" align="center"><a accesskey="h" href="multi_spring-cloud-function.html">Home</a></td><td width="40%" align="right" valign="top"> 2. Getting Started</td></tr></table></div></body></html> |