Java Service Development Guide

Off the many options available for picking a framework to build Java Rest services in we’ve chosen Dropwizard (current version 1.0.6) + Maven.

Configuration

Service configuration should be externalized from service code base in accordance with 12 Factor best practices. We can accomplish that by using Dropwizard Template Config bundle. Add the maven dependency

<dependency>
    <groupId>de.thomaskrille</groupId>
    <artifactId>dropwizard-template-config</artifactId>
    <version>1.5.0</version>
</dependency>

… and add TemplateConfigBundle to the Bootstrap object..

@Override
public void initialize(final Bootstrap<Configuration> bootstrap) {
    ...
    bootstrap.addBundle(new TemplateConfigBundle());
    ...
}

Sample Config file:

server:
  type: simple
  connector:
    type: http
    # replacing environment variables
    port: ${PORT}
logging:
  # with default values too
  level: ${LOG_LEVEL!'WARN'}
  appenders:
    # system properties also work
    - type: ${log_appender!'console'}

Logging

Request Id Tracing

Use this library allows us to intercept a request and generate a request UUID if none exists. Follow the steps outlined on the github page. Additionally add the following to config :

requestTracker:
  headerName: X-Request-Id

Logentires

Please refer to this library to setup Logentires with Dropwizard service - https://githttps://github.com/service-enabled/dropwizard-request-tracker