通过java中的spring servlet过滤器将位置设置为响应头参数

Question

我尝试在特定 API 的响应标头中添加一个位置。但是，当我通过Postman向相关API发送请求时，我在响应标头中看不到位置参数。 Postman 仅显示

content-type

、传输编码、日期、保持活动和连接参数，但标头内没有位置。

我使用开放的API代码生成并生成API的接口类。我在控制器类中重写了这些接口类中的方法，因此无法更改方法签名。我正在共享控制器方法和 servlet 过滤器，我尝试在

headers

中发送位置。如何查看响应标头中的位置参数？ :

控制器方法：

@ResponseStatus(HttpStatus.CREATED)  // Sets 201 Created status
public FlightInfo addFlight(final FlightInfo request) {
    // Call the service to add the flight
    final FlightInfo savedFlight = flightService.addFlight(request);

    // Set the flight ID as a request attribute for the filter to use
    ServletRequestAttributes attr = (ServletRequestAttributes) RequestContextHolder.currentRequestAttributes();
    HttpServletRequest httpRequest = attr.getRequest();
    httpRequest.setAttribute("flightId", savedFlight.getFlightId());

    // Return the FlightInfo response
    return savedFlight;
}

Servlet 过滤器：

    import java.io.IOException;
import java.net.URI;
import java.util.UUID;

import jakarta.servlet.Filter;
import jakarta.servlet.FilterChain;
import jakarta.servlet.FilterConfig;
import jakarta.servlet.ServletException;
import jakarta.servlet.ServletRequest;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

@Component
public class FlightFilter implements Filter {
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
    throws IOException, ServletException {

    HttpServletRequest request = (HttpServletRequest) servletRequest;
    HttpServletResponse response = (HttpServletResponse) servletResponse;

    // Proceed with the filter chain to allow the controller to process the request
    chain.doFilter(request, response);

    // After the controller has processed the request, check if it’s a POST request to /flight
    if (request.getRequestURI().contains("/flight") && request.getMethod().equalsIgnoreCase("POST")) {
        // Retrieve the flight ID from a request attribute
        UUID flightId = (UUID) request.getAttribute("flightId");

        if (flightId != null) {
            // Build the Location URI for the newly created flight
            URI location = ServletUriComponentsBuilder
                .fromCurrentRequest()
                .path("/{id}")
                .buildAndExpand(flightId)
                .toUri();

            // Add the Location header to the response
            response.setHeader("Location", location.toString());
            System.out.println("Location header set: " + location.toString());
        } else {
            System.out.println("Flight ID is null");
        }
    } else {
        System.out.println("Request URI: " + request.getRequestURI() + ", Method: " + request.getMethod());
    }
}

Answer 1

您确定您的文件管理器已被调用吗？您在过滤器的日志中看到任何输出吗？ （顺便说一句，我建议使用记录器而不是

System.out.println

）。我认为您缺少注释

@Order

，并且可能是您的过滤器未使用。另外，由于您只想将过滤器应用于路径“/flight/*”，因此有一种更好的方法可以使用

FilterRegistrationBean

注册过滤器。请参阅此处有关该主题的好文章：How to Define a Spring Boot Filter?