/search-microservice

Tags and Geo search microservice of Sagas.Life project

Primary LanguageJava

vertx-starter-pack

Starter pack for Vert.x development. Read a wiki for preparation.

Note about IDEA

Here you could find some IDEA shortcuts that i've found the most useful(this list is being updated continuosly).

Now let's dive in this project:

Files

There are some important files to understand this project. Two main directories is common and profiles.

common

Look at build.gradle, it is the first project configuration file. You should see project dependencies, their's meanings one by one:

  • Service discovery - component, that provides an infrastructure to publish and discover various services
  • Hazlecast - default custer manager
  • Web - http server
  • Web client - asynchronous http client
  • Circuit breaker - implementation of Circuit breaker pattern
  • Health check - testing the health of the application

*Check Useful vert.x concepts section for more.

Now turn your attention to src/main/java/vertx/common folder. There are two files. Start reading Launcher.java first and MicroserviceVerticle.java second. This whole part is just two classes intended for future reuse by inheriting from them. That is why it is common - because all this code is common for our project(and lots of other vert.x projects, perhaps)

profiles

This time profiles/build.gradle contains pretty much the same libraries with few additions like google and vert.x libraries for gRPC. We won't stop here, go to profiles/src/main/java/profiles/ folder.

Launcher.java is the entry point that runs vert.x. Other classes are placed in folders:

model

This folder contains classes for transfering to main types of messages over eventbus: configuration messages and profiles messages. So here is the meaning of every class here:

  • Config is just a data class: representation of conf/config.json in plain java class
  • ConfigMessageCoded is an class that implements MessageCodec interface - general way of transportation of custom message types over eventbus and this class are used concretly to transport Config class.
  • Profile is just a data class: representation of user info in plain java class
  • ProfileMessageCodec is just like an ConfigMessageCodec but for transporting of Profile class

services

The folder contains only one file: ProfileServiceImpl.java. This class is a service for fetching profile. First it fetches Profile object, transforms it to ProfileObject object, wraps it with ProfileResponse object and passes it to client when it is requested.

verticles

This folder contains classes and here is theirs purpose:

  • ConfigurationVerticle - for configuration maintenance update/retrieval
  • ServiceDiscoveryVerticle - the name suggests the meaning, read here for more
  • ApiVerticle - for settling VertxServer(adding service for retrieval of Profile data via gRPC)
  • ProfileVerticle - just replying to Profile requests with {"Petr", "Ivanov", ... }.
  • MainVerticle - for deploying all verticles listed above

Client

ProfilesClient.java is a client class that connects to our server and prints response("Petr", "Ivanov", ... ).

The common question is: "How do our client knows the address of our server and other configuration info?". Well, it takes all this from our conf/config.json file. It is not magic.

For more - read comments in code.

Resources

This part is all about useful links to understand vert.x and this project of course(be patient):

Beginner

  • Unofficial tutorial
  • Official tutorial
  • Guide to asynchronous programming, actually all about vert.x(read the first three items)

Useful vert.x concepts

Other

Google a lot and read a lot, other info is comments in files.