riff-java-function-demo.adoc

Demo - Simple riff Java function using javac

Create the function code

1. Create the source directory and class file

   $ mkdir -p upper/functions
   $ cd upper
   $ touch ./functions/Upper.java

2. Write the function class

   Add the Function implementation

   function/Upper.java

   package functions;
   
   import java.util.function.Function;
   
   public class Upper implements Function<String, String> {
   
   	public String apply(String name) {
   		return name.toUpperCase();
   	}
   }

3. Build and package the function

   $ mkdir -p bin
   $ javac -source 1.8 -target 1.8 -d bin ./functions/Upper.java
   $ jar cvf upper.jar -C bin functions/Upper.class

Now it is time for riff

1. Create function and deploy to riff

   $ riff create java --artifact upper.jar \
       --handler 'functions.Upper'

2. Test the function running in riff

   $ riff publish -d hello -r
   Posting to http://192.168.99.100:32657/requests/upper
   HELLO