Springmvc中国际化自动配置的原理

　　在 springmvc 中通过 LocalResover 获取区域信息对象 Local（对语言信息、国家代码等的封装），进行国际化配置，在 springboot 为我们提供了默认的区域信息解析器

@Configuration(
    proxyBeanMethods = false
)
@ConditionalOnWebApplication(
    type = Type.SERVLET
)
@ConditionalOnClass({Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class})
@ConditionalOnMissingBean({WebMvcConfigurationSupport.class})
@AutoConfigureOrder(-2147483638)
@AutoConfigureAfter({DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class, ValidationAutoConfiguration.class})
public class WebMvcAutoConfiguration {
    public static final String DEFAULT_PREFIX = "";
    public static final String DEFAULT_SUFFIX = "";
    private static final String[] SERVLET_LOCATIONS = new String[]{"/"};

        @Bean
        @ConditionalOnMissingBean   //容器中没有 LocaleResolver 时
        @ConditionalOnProperty(
            prefix = "spring.mvc",
            name = {"locale"}
        )
        public LocaleResolver localeResolver() {　　　　　　　　//如果属性中指定用固定的就用固定的 FixedLocaleResolver 区域化信息解析器
            if (this.mvcProperties.getLocaleResolver() == org.springframework.boot.autoconfigure.web.servlet.WebMvcProperties.LocaleResolver.FIXED) {
                return new FixedLocaleResolver(this.mvcProperties.getLocale());
            } else {　　　　　　　　　　//否则使用  AcceptHeaderLocaleResolver 区域化信息解析器
                AcceptHeaderLocaleResolver localeResolver = new AcceptHeaderLocaleResolver();
                localeResolver.setDefaultLocale(this.mvcProperties.getLocale());
                return localeResolver;
            }
        }

AcceptHeaderLocaleResolver 在 request 请求头中获取到区域信息

public class AcceptHeaderLocaleResolver implements LocaleResolver {
    private final List<Locale> supportedLocales = new ArrayList(4);

    public Locale resolveLocale(HttpServletRequest request) {
        Locale defaultLocale = this.getDefaultLocale();
        if (defaultLocale != null && request.getHeader("Accept-Language") == null) {
            return defaultLocale;
        } else {
            Locale requestLocale = request.getLocale();
            List<Locale> supportedLocales = this.getSupportedLocales();
            if (!supportedLocales.isEmpty() && !supportedLocales.contains(requestLocale)) {
                Locale supportedLocale = this.findSupportedLocale(request, supportedLocales);
                if (supportedLocale != null) {
                    return supportedLocale;
                } else {
                    return defaultLocale != null ? defaultLocale : requestLocale;
                }
            } else {
                return requestLocale;
            }
        }
    }

默认就是更具请求头带来的区域信息获取 Local 进行国际化

我们可以通过定义自己的区域化解析器生成区域化信息

public class MyLocaleResolver implements LocaleResolver {    
    @Override
    public Locale resolveLocale(HttpServletRequest request) {
        String l = request.getParameter("l");
        Locale locale = Locale.getDefault();
        if(!StringUtils.isEmpty(l)){
            String[] split = l.split("_");
            locale = new Locale(split[0],split[1]);
        }
        return locale;
    }
    @Override
    public void setLocale(HttpServletRequest request, HttpServletResponse response, Locale locale) {
    }
}

@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {
    @Bean
    public LocaleResolver localeResolver(){
        return new MyLocaleResolver();
    }
}

来源：https://www.cnblogs.com/tombky/p/12556800.html

标签

springmvc配置