{"id":7383,"date":"2021-07-24T16:18:56","date_gmt":"2021-07-24T20:18:56","guid":{"rendered":"https:\/\/springframework.guru\/?p=7383"},"modified":"2021-09-10T08:56:52","modified_gmt":"2021-09-10T12:56:52","slug":"internationalization-with-spring-boot","status":"publish","type":"post","link":"https:\/\/springframework.guru\/internationalization-with-spring-boot\/","title":{"rendered":"Internationalization with Spring Boot"},"content":{"rendered":"

Internationalization or I18N is a process that makes your application adaptable to different languages and regions without engineering changes on the source code. You can display messages, currencies, date, time etc. according to the specific region or language, likewise you can say internationalization is a readiness of localization.<\/p>\n

Maven dependency<\/h2>\n

You will only require the basic spring boot dependencies along with lombok<\/code><\/a> dependency in your pom.xml.<\/code><\/p>\n

<dependency>\r\n    <groupId>org.projectlombok<\/groupId>\r\n    <artifactId>lombok<\/artifactId>\r\n    <optional>true<\/optional>\r\n<\/dependency>\r\n<\/pre>\n
You will also require thymeleaf<\/a> dependency to be added in as a front-end templating engine.<\/p>\n
Note: <\/strong> In our example, we are only testing the internationalization with Postman and hence, we do not require to add thymeleaf dependency.<\/p>\n
Spring Boot Internationalization Example<\/h2>\n
It is a simple application to greet a user in different languages.<\/p>\n
Internationalization requires you to define the locale configuration in a configuration class.<\/p>\n
This is the code for LocaleConfig<\/code> class.<\/p>\n
LocaleConfig.java<\/strong><\/p>\n
package guru.springframework.configuration;\r\n\r\nimport org.springframework.context.annotation.Bean;\r\nimport org.springframework.context.annotation.Configuration;\r\nimport org.springframework.context.support.ResourceBundleMessageSource;\r\nimport org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver;\r\nimport java.util.Locale;\r\n\r\n@Configuration\r\npublic class LocaleConfig {\r\n\r\n    @Bean\r\n    public AcceptHeaderLocaleResolver localeResolver() {\r\n        final AcceptHeaderLocaleResolver resolver = new AcceptHeaderLocaleResolver();\r\n        resolver.setDefaultLocale(Locale.US);\r\n        return resolver;\r\n    }\r\n\r\n    @Bean\r\n    public ResourceBundleMessageSource messageSource() {\r\n        final ResourceBundleMessageSource source = new ResourceBundleMessageSource();\r\n        source.setBasename(\"internationalization\/lang\");\r\n        return source;\r\n    }\r\n}\r\n<\/pre>\n
To determine which locale is currently being used by the application, we need to add a LocaleResolver<\/code> bean.<\/p>\n
The LocaleResolver<\/code> interface has implementations that determine the current locale based on the session<\/code>, cookies<\/code>, the Accept-Language<\/code> header, or a fixed value.<\/p>\n
In our example, we have used the AcceptHeaderLocaleResolver<\/code> to retrieve locale based on the Accept-Language<\/code> passed as a parameter.<\/p>\n
I have set a default locale with the value US<\/code>.<\/p>\n
The ResourceBundleMessageSource<\/code> bean in Line 20 is used here to resolve text messages from properties file based on different locales.<\/p>\n
You will now require a controller class to accept the incoming request and return a response to the user.<\/p>\n
The code for the GreetingsController<\/code> class is this.<\/p>\n
GreetingsController.java<\/strong><\/p>\n
package guru.springframework.controller;\r\n\r\nimport lombok.extern.slf4j.Slf4j;\r\nimport org.springframework.beans.factory.annotation.Autowired;\r\nimport org.springframework.beans.factory.annotation.Value;\r\nimport org.springframework.context.support.ResourceBundleMessageSource;\r\nimport org.springframework.web.bind.annotation.*;\r\n\r\nimport java.util.Locale;\r\n\r\n@Slf4j\r\n@RestController\r\n@RequestMapping(\"\/api\")\r\npublic class GreetingsController {\r\n\r\n    @Autowired\r\n    private ResourceBundleMessageSource source;\r\n    @Value(\"${placeholder.greetings}\")\r\n    private String greetings;\r\n\r\n    @GetMapping(\"\/message\")\r\n    public String getLocaleMessage(\r\n            @RequestHeader(name = \"Accept-Language\", required = false) final Locale locale,\r\n            @RequestParam(name = \"username\", defaultValue = \"Albert Xin\", required = false) final String username) {\r\n\r\n        log.info(\"Returning greetings for locale = {}\", locale);\r\n        return source.getMessage(greetings, new Object[]{username}, locale);\r\n    }\r\n}\r\n<\/pre>\n
Here, we have just defined a simple get method which accepts Accept-Language<\/code> as a RequestHeader<\/code> parameter and username<\/code> as the query parameter.<\/p>\n
In Line 26, we have added a log message to display the locale chosen in the console.<\/p>\n
Defining the Message Sources<\/h2>\n
Spring Boot application by default takes the message sources from src\/main\/resources<\/code> folder under the classpath. The default locale message file name should be message.properties<\/code> and files for each locale should name as messages_XX.properties<\/code>. The \u201cXX\u201d represents the locale code.<\/p>\n
The message properties are in key pair values. If any properties are not found on the locale, the application uses the default property from messages.properties<\/code> file.<\/p>\n
application.yml<\/strong><\/p>\n
placeholder:\r\n  greetings: welcome.message\r\nserver:\r\n  port: 8080\r\nspring:\r\n  application:\r\n    name: internationalization-with-springboot\r\n<\/pre>\n
Here, I have defined the spring configuration and a placeholder key for internationalization.<\/p>\n
message.properties<\/strong><\/p>\n
welcome.message=Greetings {0}\r\n<\/pre>\n
In English, the value of the key is specified here.<\/p>\n
message_fr.properties<\/strong><\/p>\n
welcome.message=Bonjour {0}\r\n<\/pre>\n
Hello<\/strong> in French translates to Bonjour<\/strong>.<\/p>\n
message_de.properties<\/strong><\/p>\n
welcome.message=Hallo {0}\r\n<\/pre>\n
Hello<\/strong> translates to Hallo<\/strong> in German.<\/p>\n
Build and Run the Application<\/h2>\n
Execute the Main Application.<\/p>\n
After that, open the Postman tool to hit the application endpoints to persist the data into the database or fetch from it.<\/p>\n
Here, each incoming request contains the Accept-Language<\/code> header, where we will specify the locale.\u00a0 Based on this locale, the appropriate message will be returned to the user.<\/p>\n
The header value is set to fr<\/code>.\u00a0 As a result, the message will be displayed in the French language.<\/p>\n
\"\"<\/a><\/p>\n
Here, I have sent the Accept-Language<\/code> header value as de<\/code> and the message will be displayed in the german language.<\/p>\n
\"\"<\/a><\/p>\n
And, when you do not specify any language, the output is this.<\/p>\n
\"\"<\/a><\/p>\n
This is the console output.<\/p>\n
\"\"<\/a><\/p>\n
Summary<\/h2>\n
In this post, we covered integrating Internationalization with a Spring Boot Project. That is to say, performing simple translations using MessageSource<\/code> implementations and LocaleResolver<\/code>,using the details of incoming HTTP requests is a very simple task now. Internationalization<\/code> helps us to make our web applications reach as wide an audience as possible. Consequently, it can be adapted and localized to different cultures, regions, and languages. On the other hand, Localization<\/code> is the adaptation of any software or mobile application product to meet the language, culture, and other requirements of each locale.<\/p>\n
You can find the source code of this post on Github<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"
Internationalization or I18N is a process that makes your application adaptable to different languages and regions without engineering changes on the source code. You can display messages, currencies, date, time etc. according to the specific region or language, likewise you can say internationalization is a readiness of localization. Maven dependency You will only require the […]Continue reading<\/a><\/p>\n","protected":false},"author":111,"featured_media":4586,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[21,104],"tags":[365,366,29],"class_list":["post-7383","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-spring","category-spring-boot","tag-internationalization","tag-locale","tag-spring-boot"],"jetpack_publicize_connections":[],"aioseo_notices":[],"modified_by":"jt","jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/springframework.guru\/wp-content\/uploads\/2015\/03\/Banner560x292_03web.jpg","jetpack_shortlink":"https:\/\/wp.me\/p5BZrZ-1V5","_links":{"self":[{"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/posts\/7383"}],"collection":[{"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/users\/111"}],"replies":[{"embeddable":true,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/comments?post=7383"}],"version-history":[{"count":23,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/posts\/7383\/revisions"}],"predecessor-version":[{"id":7607,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/posts\/7383\/revisions\/7607"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/media\/4586"}],"wp:attachment":[{"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/media?parent=7383"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/categories?post=7383"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/springframework.guru\/wp-json\/wp\/v2\/tags?post=7383"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}