Dropwizard s configuration is specified in yaml by default While yaml has nice properties you may prefer json or some other format Dropwizard s documentation claims If your configuration file doesn t end in yml or yaml Dropwizard tries to parse it as a JSON file This is easily disproved by renaming example yml to example json and trying to run the application It will incorrectly start without error Since json syntax is a subset of yml syntax you can go ahead and convert your configuration file to json without changing the file extension from yaml or yml However this approach doesn t prevent you from accidentally using yaml syntax You can change your application to use json for its configuration using uses json5 syntax by default using optional features in Jackson So you ll still be able to include comments inside your configuration files After adding the bundle you ll have to convert your configuration files to json5 and rename them So becomes Configuration files used in tests must be converted as well So becomes JsonConfigurationFactoryFactory @Override public void initialize Bootstrap<HelloWorldConfiguration> bootstrap bootstrap setConfigurationFactoryFactory new JsonConfigurationFactoryFactory<> JsonConfigurationFactoryFactory example yml example json5 DropwizardAppRule DropwizardAppExtension src test resources test example yml src test resources test example json5

lives in the module JsonConfigurationFactoryFactory liftwizard configuration factory json <dependency> <groupId>io liftwizard< groupId> <artifactId>liftwizard configuration factory json< artifactId> < dependency>