Internationalization

Overview

Beaver IoT supports multiple languages by default and provides a complete internationalization solution.

Locale

Locale is used as the current language environment. The Locale of the current thread is stored in the LocaleContext.

Message Files

Storage directory: src/main/resources/i18n

Message file formats are messages.properties and messages_{languageCode}[_{regionCode}].properties, for example:

info

messages.properties: The fallback message file. This file is read when no corresponding language file is found for the current locale.

messages_en.properties: Read when the locale is ENGLISH. The default locale is ENGLISH.

messages_zh_CN.properties: Read when the locale is SIMPLIFIED_CHINESE.

The content format of message files is {messageCode}={message}, for example:

messages_en.properties

example-module.hello.world=Hello World

messages_zh_CN.properties

example-module.hello.world=你好，世界

Message Code Convention

To ensure messages between modules do not interfere with each other, message code naming is standardized. A module name must be added as a prefix to the message code. The message code format is: {moduleName}.{detailCode}

For example, if the module name is device-template-service, the message file content would be:

device-template-service.code1=xxx
device-template-service.code2=yyy
device-template-service.code3=zzz

For use within integrations, the message code format must follow: integrations.{integrationId}.{detailCode}

For example, if the integration name is mqtt-device, the message file content would be:

integrations.mqtt-device.code1=xxx
integrations.mqtt-device.code2=yyy
integrations.mqtt-device.code3=zzz

warning

Message codes will be strictly reviewed as one of the development standards. Please follow the message code conventions during development.

Usage

Using the integration name example-integration as an example.

Create Message Files

1. Create an i18n directory under src/main/resources.

2. In the message directory, create the fallback message file and language-specific files as shown below: messages.properties

   messages.properties

   integrations.example-integration.hello.world=Hello world
   integrations.example-integration.hello.message=Hello {0}, welcome to {1}

   messages_en.properties

   integrations.example-integration.hello.world=Hello world
   integrations.example-integration.hello.message=Hello {0}, welcome to {1}

   messages_zh_CN.properties

   integrations.example-integration.hello.world=你好，世界
   integrations.example-integration.hello.message=你好 {0}，欢迎来到 {1}

Import Message Source

Internationalized messages are read by injecting the message source MergedResourceBundleMessageSource.

Constructor Injection

@Slf4j
@Service
public class ExampleService {
    private final MergedResourceBundleMessageSource messageSource;
    
    public ExampleService(MergedResourceBundleMessageSource messageSource) {
        this.messageSource = messageSource;
    }
}

@Autowired Annotation Injection

@Slf4j
@Service
public class ExampleService {
    @Autowired
    private MergedResourceBundleMessageSource messageSource;
}

Message Retrieval

After injecting the message source, you can retrieve messages corresponding to the locale using the provided methods:

// Get message by code, arguments, default message, and Locale
public String getMessage(String code, Object[] args, String defaultMessage, Locale locale);
// Get message by code, arguments, and Locale
public String getMessage(String code, Object[] args, Locale locale);
// Get message by code, arguments, and default message, using the current thread's Locale
public String getMessage(String code, Object[] args, String defaultMessage);
// Get message by code and arguments, using the current thread's Locale
public String getMessage(String code, Object[] args);
// Get message by code, using the current thread's Locale
public String getMessage(String code);

Example Code

@Slf4j
@Service
public class ExampleService {
    private final MergedResourceBundleMessageSource messageSource;
    
    public ExampleService(MergedResourceBundleMessageSource messageSource) {
        this.messageSource = messageSource;
    }

    public void testSimpleMessage() {
        log.info(messageSource.getMessage("hello.world"));
    }

    public void testMessageWithArgs() {
        log.info(messageSource.getMessage("hello.message", new Object[]{"Panda", "Milesight"}));
    }

    public void testChineseMessageWithArgs() {
        log.info(messageSource.getMessage("hello.message", new Object[]{"Panda", "Milesight"},
                Locale.SIMPLIFIED_CHINESE));
    }
}