1. Internationalization

Spring Boot supports localized messages so that your application can cater to users of different language preferences. By default, Spring Boot looks for the presence of a messages resource bundle at the root of the classpath.

The auto-configuration applies when the default properties file for the configured resource bundle is available (i.e. messages.properties by default). If your resource bundle contains only language-specific properties files, you are required to add the default. If no properties file is found that matches any of the configured base names, there will be no auto-configured MessageSource.

The basename of the resource bundle as well as several other attributes can be configured using the spring.messages namespace, as shown in the following example:

spring.messages.basename=messages,config.i18n.messages
spring.messages.fallback-to-system-locale=false
spring.messages.basename supports comma-separated list of locations, either a package qualifier or a resource resolved from the classpath root.

See MessageSourceProperties for more supported options.