是否有任何选项可以在 Spring Boot 中为所有 @RequestHeaders 添加默认值？

Question

是否有任何选项可以在 Spring Boot 中为所有 @RequestHeader 添加默认值？

@RequestHeader(value = "User-Accept-Language", defaultValue = "en-IN") String localeCd

我正在复制/粘贴到所有 API。避免代码重复的任何帮助！

Answer 1

这是一个关于如何使用 spring WebFlux 为 header 提供默认值的示例

@Component
public class CorrelationIdFilter implements WebFilter {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
        var correlationId = exchange.getRequest().getHeaders().getFirst(CORRELATION_ID_HEADER);
        if (correlationId == null || correlationId.isEmpty()) {
            correlationId = UUID.randomUUID().toString();
            ServerHttpRequest mutatedRequest = exchange.getRequest()
                    .mutate()
                    .header(CORRELATION_ID_HEADER, correlationId)
                    .build();
            exchange = exchange
                    .mutate()
                    .request(mutatedRequest)
                    .build();
        }
        exchange.getResponse().getHeaders().add(CORRELATION_ID_HEADER, correlationId);
        return chain.filter(exchange);
    }
}

这是针对 Spring web 的

@Component
public class CorrelationIdFilter implements Filter {

    static final String CORRELATION_ID_HEADER = "X-Correlation-ID";

    @Override
    public void init(FilterConfig filterConfig) {
        // empty
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest httpRequest = (HttpServletRequest) request;
        String correlationId = httpRequest.getHeader(CORRELATION_ID_HEADER);
        if (correlationId == null) {
           correlationId = XidFactory.nextXid();
           ((HttpServletResponse) response).addHeader(CORRELATION_ID_HEADER, correlationId);
        }
        
        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {
        // empty
    }
}

Answer 2

我没有发现任何已经为添加带有值的标头的注释所做的任何事情，所以我自己做了。下面是代码，很简单，我是用spring AOP做的

1. 我创建了注释类

   import java.lang.annotation.ElementType;
   import java.lang.annotation.Retention;
   import java.lang.annotation.RetentionPolicy;
   import java.lang.annotation.Target;
   
   @Retention(RetentionPolicy.RUNTIME)
   @Target(ElementType.METHOD)
   public @interface ResponseHeader {
   
       public String key() default "";
   
       public String value() default "";
   }
   

   还有一个用于包含一组标头注释的

   import java.lang.annotation.ElementType;
   import java.lang.annotation.Retention;
   import java.lang.annotation.RetentionPolicy;
   import java.lang.annotation.Target;
   
   
   @Retention(RetentionPolicy.RUNTIME)
   @Target(ElementType.METHOD)
   public @interface ResponseHeaders {
   
       public ResponseHeader[] headers();
   }
   

2. 用于捕获 restControllers 的 AOP 类（您可以自定义 AOP 以根据需要设置自己的切入点：

   import YOUR_PACKAGE_ANNOTATION.ResponseHeaders;
   import org.aspectj.lang.annotation.After;
   import org.aspectj.lang.annotation.Aspect;
   import org.aspectj.lang.annotation.Pointcut;
   import org.springframework.stereotype.Component;
   import org.springframework.web.context.request.RequestContextHolder;
   import org.springframework.web.context.request.ServletRequestAttributes;
   
   import javax.servlet.http.HttpServletResponse;
   import java.util.List;
   
   /**
    * Aspect for inserting headers on the methods of the @RestController         
    annotated classes
    */
    @Aspect
    @Component
    public class ResponseHeadersAnnotation {
   
    /**
    * Pointcut for filtering just classes with @RestController annotation
    */
   @Pointcut("@within(org.springframework.web.bind.annotation.RestController)")
   public void restControllerClass() {
   }
   
   /**
    * It adds the headers to the response of the method of the controller
    *
    * @param responseHeaders
    */
   @After("restControllerClass() && @annotation(responseHeaders)")
   public void addHeaders(final ResponseHeaders responseHeaders) {
       final HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
       List.of(responseHeaders.headers()).forEach(responseHeader -> response.setHeader(responseHeader.key(), responseHeader.value()));
    }
   }
   

3. 这是一个如何在控制器中使用它的示例：

   @GetMapping(value = {"/ServiceTicketCollection", "/ServiceRequestCollection"})
   @ResponseHeaders(headers = {
           @ResponseHeader(key = "cookie1", value = "value1"),
           @ResponseHeader(key = "cookie2, value = "value2")
   })
   public Object restControllerMethod() {
       ...
   }