SpringBoot国际化：创建多语言支持的Web应用

SpringBoot国际化：创建多语言支持的Web应用

介绍

SpringBoot作为一个强大的框架，提供了便捷的国际化支持，使开发者能够轻松创建多语言支持的Web应用。通过使用SpringBoot的MessageSource，开发者可以在应用中实现动态的语言切换。

设置国际化

1. 添加依赖，springboot相关依赖
2. 添加配置文件
   
   
3. yml文件

spring:
  messages:
    basename: i18n/messages
    encoding: UTF-8

注意：basename后面的messages位配置文件后面Resource Bundle后面的名字

4. 通过拦截器+aop，实现拦截请求做到国际化

• i18n配置

@Configuration
public class I18nConfig implements WebMvcConfigurer {
    @Bean
    public LocaleResolver localeResolver() {
        SessionLocaleResolver slr = new SessionLocaleResolver();
        //设置默认语言，美式英文
        slr.setDefaultLocale(Locale.US);
        return slr;
    }

    @Bean
    public LocaleChangeInterceptor localeChangeInterceptor() {
        LocaleChangeInterceptor lci = new LocaleChangeInterceptor();
        //参数名与前端方法携带参数名一致
        lci.setParamName("Accept-Language");
        return lci;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(localeChangeInterceptor());
    }
}

• 拦截器，拦截所有请求

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyRequestInterceptor())
                .addPathPatterns("/**");
    }
}

• aop

通过aop拦截到想要拦截所有请求的返回值，并根据前端传来的language进行国际化配置。

1. 获取到语言
2. 修改返回值，通过code找到对应的name，这个我都存在一个枚举类中
3. 通过name找到配置文件中对应的配置，并取出，修改返回值

@Aspect
@Component
public class ChangeLanguageAspect {

    private static final Logger logger = LoggerFactory.getLogger(ChangeLanguageAspect.class);

    private static final Map<String, Locale> map = new HashMap(){
        {
            put("zh_CN", Locale.SIMPLIFIED_CHINESE);
            put("en_US", Locale.US);
            put("zh_TW", Locale.TRADITIONAL_CHINESE);
            put("th_TH", new Locale("th", "TH"));
            put("default", Locale.getDefault());
        }
    };

    @Resource
    private MessageSource messageSource;

    @Resource
    private LocaleResolver localeResolver;

    @Pointcut("within(@org.springframework.web.bind.annotation.RestController *) || within(@org.springframework.stereotype.Controller *)")
    public void i18nPointCut() {}

    @AfterReturning(pointcut = "i18nPointCut()", returning = "result")
    public void doAfterReturning(Object result) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();
        HttpServletResponse response = attributes.getResponse();

        // 获取语言
        String language = MyRequestInterceptor.REQUEST_ID_THREAD_LOCAL.get();
        if (StringUtil.isEmptyWithTrim(language) || !map.containsKey(language)){
            language = "default";
        }
        localeResolver.setLocale(request, response, map.get(language));
        Locale locale = LocaleContextHolder.getLocale();
        System.out.println(locale);

        // 修改返回，获取到返回值code，找到对应的name，从而在配置文件中找到对应的字段
        ServiceResponse<?> serviceResponse = (ServiceResponse<?>) result;
        int code = serviceResponse.getCode();
        GlobalErrorCode globalErrorCode = GlobalErrorCode.fromCode(code);
        String apiServiceError = messageSource.getMessage(globalErrorCode.name(), null, locale);
        logger.info("info,{}",apiServiceError);
        logger.info("result,{}",result);
        ((ServiceResponse<?>) result).setMessage(apiServiceError);
    }
}