A first cut at updating and simplifying the Java FDK Readme. Removed user tutorial already included in tutorials. Reorganized and simplified. More work to do reviewing each of the docs linked here.

michael-w-williams · michael-w-williams · commit d85e3a18c69d · 2019-03-20T17:35:03.000-06:00
diff --git a/README.md b/README.md
@@ -1,319 +1,58 @@
-# Fn Java Functions Developer Kit (FDK)
 [![CircleCI](https://circleci.com/gh/fnproject/fdk-java.svg?style=svg&circle-token=348bec5610c34421f6c436ab8f6a18e153cb1c01)](https://circleci.com/gh/fnproject/fdk-java)
 
-This project adds support for writing functions in Java on the [Fn
-platform](https://github.com/fnproject/fn), with full support for Java 11
-as the default out of the box.
-
-# FAQ
-Some common questions are answered in [our FAQ](docs/FAQ.md).
-
-# Quick Start Tutorial
-
-By following this step-by-step guide you will learn to create, run and deploy
-a simple app written in Java on Fn.
-
-## Pre-requisites
-
-Before you get started you will need the following things:
-
-* The [Fn CLI](https://github.com/fnproject/cli) tool
-* [Docker-ce 17.06+ installed locally](https://docs.docker.com/engine/installation/)
-
-### Install the Fn CLI tool
-
-To install the Fn CLI tool, just run the following:
-
-```
-curl -LSs https://raw.githubusercontent.com/fnproject/cli/master/install | sh
-```
-
-This will download a shell script and execute it. If the script asks for
-a password, that is because it invokes sudo.
-
-## Your first Function
-
-### 1. Create your first Java Function:
-
-```bash
-$ mkdir hello-java-function && cd hello-java-function
-$ fn init --runtime=java --name your_dockerhub_account/hello
-Runtime: java
-function boilerplate generated.
-func.yaml created
-```
-
-This creates the boilerplate for a new Java Function based on Maven and Oracle
-Java 11. The `pom.xml` includes a dependency on the latest version of the Fn
-Java FDK that is useful for developing your Java functions.
-
-You can now import this project into your favourite IDE as normal.
-
-### 2. Deep dive into your first Java Function:
-We'll now take a look at what makes up our new Java Function. First, lets take
-a look at the `func.yaml`:
-
-```bash
-$ cat func.yaml
-name: your_dockerhub_account/hello
-version: 0.0.1
-runtime: java
-cmd: com.example.fn.HelloFunction::handleRequest
-```
-
-The `cmd` field determines which method is called when your function is
-invoked. In the generated Function, the `func.yaml` references
-`com.example.fn.HelloFunction::handleRequest`. Your functions will likely live
-in different classes, and this field should always point to the method to
-execute, with the following syntax:
-
-```text
-cmd: <fully qualified class name>::<method name>
-```
-
-For more information about the fields in `func.yaml`, refer to the [Fn platform
-documentation](https://github.com/fnproject/fn/blob/master/docs/function-file.md)
-about it.
-
-Let's also have a brief look at the source:
-`src/main/java/com/example/fn/HelloFunction.java`:
-
-```java
-package com.example.fn;
-
-public class HelloFunction {
-
-    public String handleRequest(String input) {
-        String name = (input == null || input.isEmpty()) ? "world"  : input;
-
-        return "Hello, " + name + "!";
-    }
-
-}
-```
-
-The function takes some optional input and returns a greeting dependent on it.
-
-### 3. Run your first Java Function:
-You are now ready to run your Function locally using the Fn CLI tool.
-
-```bash
-$ fn build
-Building image your_dockerhub_account/hello:0.0.1
-Sending build context to Docker daemon  14.34kB
-Step 1/11 : FROM fnproject/fn-java-fdk-build:jdk11-latest as build-stage
- ---> 5435658a63ac
-Step 2/11 : WORKDIR /function
- ---> 37340c5aa451
-
-...
-
-Step 5/11 : RUN mvn package dependency:copy-dependencies -DincludeScope=runtime -DskipTests=true -Dmdep.prependGroupId=true -DoutputDirectory=target --fail-never
----> Running in 58b3b1397ba2
-[INFO] Scanning for projects...
-Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-compiler-plugin/3.3/maven-compiler-plugin-3.3.pom
-Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-compiler-plugin/3.3/maven-compiler-plugin-3.3.pom (11 kB at 21 kB/s)
-
-...
-
-[INFO] ------------------------------------------------------------------------
-[INFO] BUILD SUCCESS
-[INFO] ------------------------------------------------------------------------
-[INFO] Total time: 2.228 s
-[INFO] Finished at: 2017-06-27T12:06:59Z
-[INFO] Final Memory: 18M/143M
-[INFO] ------------------------------------------------------------------------
-
-...
-
-Function your_dockerhub_account/hello:0.0.1 built successfully.
-
-$ fn run
-Hello, world!
-```
-
-The next time you run this, it will execute much quicker as your dependencies
-are cached. Try passing in some input this time:
-
-```bash
-$ echo -n "Universe" | fn run
-...
-Hello, Universe!
-```
-
-### 4. Testing your function
-The Fn Java FDK includes a testing library providing useful [JUnit
-4](http://junit.org/junit4/) rules to test functions. Look at the test in
-`src/test/java/com/example/fn/HelloFunctionTest.java`:
-
-```java
-package com.example.fn;
-
-import com.fnproject.fn.testing.*;
-import org.junit.*;
-
-import static org.junit.Assert.*;
-
-public class HelloFunctionTest {
-
-    @Rule
-    public final FnTestingRule testing = FnTestingRule.createDefault();
-
-    @Test
-    public void shouldReturnGreeting() {
-        testing.givenEvent().enqueue();
-        testing.thenRun(HelloFunction.class, "handleRequest");
-
-        FnResult result = testing.getOnlyResult();
-        assertEquals("Hello, world!", result.getBodyAsString());
-    }
-
-}
-```
-
-This test is very simple: it just enqueues an event with empty input and then
-runs the function, checking its output. Under the hood, the `FnTestingRule` is
-actually instantiating the same runtime wrapping function invocations, so that
-during the test your function will be invoked in exactly the same way that it
-would when deployed.
-
-There is much more functionality to construct tests in the testing library.
-Testing functions is covered in more detail in [Testing
-Functions](docs/TestingFunctions.md).
-
-### 5. Run using HTTP and the local Fn server
-The previous example used `fn run` to run a function directly via docker, you
-can also  use the Fn server locally to test the deployment of your function and
-the HTTP calls to your functions.
-
-Open another terminal and start the Fn server:
-
-```bash
-$ fn start
-```
-
-Then in your original terminal create an app:
-
-```bash
-$ fn create app java-app
-Successfully created app: java-app
-```
-
-Now deploy your Function using the `fn deploy` command. This will bump the
-function's version up, rebuild it, and push the image to the Docker registry,
-ready to be used in the function deployment. Finally it will create a route on
-the local Fn server, corresponding to your function.
-
-We are using the `--local` flag to tell fn to skip pushing the image anywhere
-as we are just going to run this on our local fn server that we started with
-`fn start` above.
-
-```bash
-$ fn deploy --app java-app --local
-...
-Bumped to version 0.0.2
-Building image hello:0.0.2
-Sending build context to Docker daemon  14.34kB
-
-...
-
-Successfully built bf2b7fa55520
-Successfully tagged your_dockerhub_account/hello:0.0.2
-Updating route /hello-java-function using image your_dockerhub_account/hello:0.0.2...
-```
-
-Call the Function via the Fn CLI:
-
-```bash
-$ fn call java-app /hello-java-function
-Hello, world!
-```
-
-You can also call the Function via curl:
+# Fn Java Functions Developer Kit (FDK)
+The Java Function Developer Kit (FDK) makes it easy to deploy Java functions to Fn with full support for Java 11+ as the default out of the box.
 
-```bash
-$ curl http://localhost:8080/r/java-app/hello-java-function
-Hello, world!
+## Install
+MacOS installation:
+```sh
+brew update && brew install fn
 ```
 
-### 6. Something more interesting
-The Fn Java FDK supports [flexible data binding](docs/DataBinding.md)  to make
-it easier for you to map function input and output data to Java objects.
-
-Below is an example to of a Function that returns a POJO which will be
-serialized to JSON using Jackson:
-
-```java
-package com.example.fn;
-
-public class PojoFunction {
-
-    public static class Greeting {
-        public final String name;
-        public final String salutation;
-
-        public Greeting(String salutation, String name) {
-            this.salutation = salutation;
-            this.name = name;
-        }
-    }
-
-    public Greeting greet(String name) {
-        if (name == null || name.isEmpty())
-            name = "World";
-
-        return new Greeting("Hello", name);
-    }
-
-}
-```
+or
 
-Update your `func.yaml` to reference the new method:
+Alternatively for Linux/Unix/MacOS:
 
-```yaml
-cmd: com.example.fn.PojoFunction::greet
+```sh
+curl -LSs https://raw.githubusercontent.com/fnproject/cli/master/install | sh
 ```
 
-Now run your new function:
-
-```bash
-$ fn run
-...
-{"name":"World","salutation":"Hello"}
+## General Information
+* See the Fn [Quickstart](https://github.com/fnproject/fn/blob/master/README.md) for sample commands.
+* [Detailed installation instructions](http://fnproject.io/tutorials/install/).
+* [Configure your CLI Context](http://fnproject.io/tutorials/install/#ConfigureyourContext).
+* For a list of commands see [Fn CLI Command Guide and Reference](https://github.com/fnproject/docs/blob/master/cli/README.md).
+* For general information see Fn [docs](https://github.com/fnproject/docs) and [tutorials](https://fnproject.io/tutorials/).
 
-$ echo -n Michael | fn run
-...
-{"name":"Michael","salutation":"Hello"}
-```
+## Fn Java FDK Development Information
+### Contributing
+Please see [CONTRIBUTING.md](CONTRIBUTING.md).
 
-## 7. Where do I go from here?
+### Fn Java FDK FAQ
+Some common questions are answered in [our FAQ](docs/FAQ.md).
 
-Learn more about the Fn Java FDK by reading the next tutorials in the series.
-Also check out the examples in the [`examples` directory](examples) for some
-functions demonstrating different features of the Fn Java FDK.
+### Fn Java FDK Tutorials and Examples
 
-### Configuring your function
+#### Examples
+Check out Java FDK examples in the [`examples`](examples) directory for
+functions demonstrating different Fn Java FDK features.
 
-If you want to set up the state of your function object before the function is
-invoked, and to use external configuration variables that you can set up with
-the Fn tool, have a look at the [Function
+#### Configuring your Function
+Want to set up function object state before the function is invoked using external configuration variables?  Have a look at the [Function
 Configuration](docs/FunctionConfiguration.md) tutorial.
 
-### Handling HTTP requests
-
-If your function serves an HTTP trigger you may want to access HTTP details such as request or response headers or the HTTP status , check out [Accessing HTTP Information From Functions](docs/HTTPGatewayFunctions.md).
-
-### Input and output bindings
+#### Handling HTTP Requests
+Want to access HTTP details such as request or response headers or the HTTP status? Check out [Accessing HTTP Information from Functions](docs/HTTPGatewayFunctions.md).
 
+#### Input and Output Bindings
 You have the option of taking more control of how serialization and
 deserialization is performed by defining your own bindings.
 
 See the [Data Binding](docs/DataBinding.md) tutorial for other out-of-the-box
 options and the [Extending Data Binding](docs/ExtendingDataBinding.md) tutorial
 for how to define and use your own bindings.
 
-### Asynchronous workflows
-
+#### Asynchronous Workflows
 Suppose you want to call out to some other function from yours - perhaps
 a function written in a different language, or even one maintained by
 a different team. Maybe you then want to do some processing on the result. Or
@@ -323,13 +62,5 @@ function, but you don't want to pay for execution time while you're waiting for
 someone else to do their work.
 
 If this sounds like you, then have a look at the [Fn Flow
-quickstart](docs/FnFlowsUserGuide.md).
-
-# Get help
+Quickstart](docs/FnFlowsUserGuide.md).
 
-   * Come over and chat to us on the [fnproject Slack](https://join.slack.com/t/fnproject/shared_invite/enQtMjIwNzc5MTE4ODg3LTdlYjE2YzU1MjAxODNhNGUzOGNhMmU2OTNhZmEwOTcxZDQxNGJiZmFiMzNiMTk0NjU2NTIxZGEyNjI0YmY4NTA).
-   * Raise an issue in [our github](https://github.com/fnproject/fn-java-fdk/).
-
-# Contributing
-
-Please see [CONTRIBUTING.md](CONTRIBUTING.md).
