bijukunjummen/sample-webflux-func-cassandra

Spring Webflux sample with reactive endpoints

This is a sample application demonstrating Spring 5 Webflux framework with endpoints written in a functional style as opposed to an annotation based style demonstrated here. It uses Spring Data Cassandra’s support for reactive libraries to provide an end to end reactive flow.

A blog post accompanying this sample is here

Install a local Cassandra

The simplest way to install Cassandra is via the excellent ccm tool.

If you are using a Mac-OSX, you may have to add more loopback interfaces this way:

sudo ifconfig lo0 alias 127.0.0.2 up
sudo ifconfig lo0 alias 127.0.0.3 up

And bring up a 3 node Cassandra 3.9 based cluster:

ccm create test -v 3.9 -n 3 -s --vnodes

Connect to one of the nodes:

ccm node1 cqlsh

And run these cql statements

CREATE KEYSPACE IF NOT EXISTS sample WITH replication = {'class':'SimpleStrategy', 'replication_factor':1};

use sample;

CREATE TABLE IF NOT EXISTS  sample.hotels (
    id UUID,
    name varchar,
    address varchar,
    state varchar,
    zip varchar,
    primary key(id)
);

CREATE TABLE IF NOT EXISTS  sample.hotels_by_letter (
    first_letter varchar,
    hotel_name varchar,
    hotel_id UUID,
    address varchar,
    state varchar,
    zip varchar,
    primary key((first_letter), hotel_name, hotel_id)
);


CREATE MATERIALIZED VIEW sample.hotels_by_state AS
SELECT id, name, address, state, zip FROM hotels
WHERE state IS NOT NULL AND id IS NOT NULL AND name IS NOT NULL
PRIMARY KEY ((state), id)
WITH CLUSTERING ORDER BY (name DESC);

Run the App

./gradlew clean bootRun

Populate Data

Assuming that httpie is installed in your machine

http POST 'http://localhost:8080/hotels' state="WA" name="A Sample Hotel" zip="00001" address="Address 1"
http POST 'http://localhost:8080/hotels' state="WA" name="B Sample Hotel" zip="00002" address="Address 2"
http POST 'http://localhost:8080/hotels' state="OR" name="C Sample Hotel" zip="00003" address="Address 3"

OR with CURL

curl -X "POST" "http://localhost:8080/hotels" \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -d $'{
  "name": "A Sample Hotel",
  "address": "Address 1",
  "state": "WA",
  "zip": "00001"
}'

curl -X "POST" "http://localhost:8080/hotels" \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -d $'{
  "name": "B Sample Hotel",
  "address": "Address 2",
  "state": "WA",
  "zip": "00002"
}'

curl -X "POST" "http://localhost:8080/hotels" \
     -H "Accept: application/json" \
     -H "Content-Type: application/json" \
     -d $'{
  "name": "C Sample Hotel",
  "address": "Address 3",
  "state": "OR",
  "zip": "10001"
}'

Query Data

Get hotels with names starting with "A" - internally makes use of a table with duplicated content, maintained with first letter as the partition key

http GET 'http://localhost:8080/hotels/startingwith/A'

OR with Curl

curl -X "GET" "http://localhost:8080/hotels/startingwith/A" \
     -H "Accept: application/json"

Get Hotels from State - makes use of a materialized view

http GET 'http://localhost:8080/hotels/fromstate/OR'

curl -X "GET" "http://localhost:8080/hotels/fromstate/OR" \
     -H "Accept: application/json"

Delete Data

Delete Hotels by id

http DELETE 'http://localhost:8080/hotels/<id>'

curl -X "DELETE" "http://localhost:8080/hotels/<id>" -H "Accept: application/json"