在Spring中给HttpServletRequest添加自定义Header的完整指南

public class RequestWrapper extends HttpServletRequestWrapper {
    
    // 可选，如需对body数据做处理
    private String mBody;
    private Map<String, String> headerMap = new HashMap<>();

    public RequestWrapper(HttpServletRequest request) {
        super(request);
        mBody = getBodyString(request);
    }

    /**
     * 添加自定义 Header
     */
    public void addHeader(String name, String value) {
        headerMap.put(name, value);
    }

    @Override
    public String getHeader(String name) {
        String headerValue = super.getHeader(name);
        if (headerMap.containsKey(name)) {
            headerValue = headerMap.get(name);
        }
        return headerValue;
    }

    @Override
    public Enumeration<String> getHeaderNames() {
        List<String> names = Collections.list(super.getHeaderNames());
        names.addAll(headerMap.keySet());
        return Collections.enumeration(names);
    }

    @Override
    public Enumeration<String> getHeaders(String name) {
        List<String> values = Collections.list(super.getHeaders(name));
        if (headerMap.containsKey(name)) {
            values.add(headerMap.get(name));
        }
        return Collections.enumeration(values);
    }

    /**
     * 获取请求体内容
     */
    private String getBodyString(ServletRequest request) {
        StringBuilder sb = new StringBuilder();
        try (InputStream inputStream = request.getInputStream();
             BufferedReader reader = new BufferedReader(
                 new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
            
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            logger.error("读取请求体失败", e);
        }
        return sb.toString();
    }

    // 其他必要的方法重写...
}

@Component
@Order(10000)
@WebFilter(filterName = "HttpServletRequestFilter", urlPatterns = "/*")
public class HttpServletRequestFilter implements Filter {
    
    private static final Set<String> EXCLUDE_PATHS = Set.of(
        "/health", "/actuator/health", "/favicon.ico"
    );
    
    private static final Logger logger = LoggerFactory.getLogger(HttpServletRequestFilter.class);

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, 
                         FilterChain filterChain) throws IOException, ServletException {
        
        HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;
        String path = httpRequest.getRequestURI();
        
        // 跳过不需要处理的路径
        if (shouldSkipProcessing(path)) {
            filterChain.doFilter(servletRequest, servletResponse);
            return;
        }
        
        // 包装请求
        RequestWrapper requestWrapper = new RequestWrapper(httpRequest);
        
        // 设置自定义 Header，这里可以在别处设置，比如从token中解析后调用setCustomHeaders
        setCustomHeaders(requestWrapper);
        
        // 继续过滤器链
        filterChain.doFilter(requestWrapper, servletResponse);
    }

    /**
     * 判断是否跳过处理
     */
    private boolean shouldSkipProcessing(String path) {
        return EXCLUDE_PATHS.stream().anyMatch(path::startsWith);
    }

    /**
     * 设置自定义 Header
     */
    private void setCustomHeaders(HttpServletRequest request) {
        try {
            // 示例：从用户上下文中获取租户ID
            User user = UserContext.getUser();
            if (user != null && user.getTenantId() != null) {
                setHeaderTenantId(request, user.getTenantId());
            }
            
            // 可以添加更多自定义 Header
            // setOtherHeaders(request);
            
        } catch (Exception e) {
            logger.warn("设置自定义 Header 失败", e);
        }
    }

    /**
     * 设置租户ID Header
     */
    private void setHeaderTenantId(HttpServletRequest request, String tenantId) {
        if (request instanceof StandardMultipartHttpServletRequest) {
            // 处理文件上传请求
            StandardMultipartHttpServletRequest multipartRequest = 
                (StandardMultipartHttpServletRequest) request;
            HttpServletRequest originalRequest = multipartRequest.getRequest();
            if (originalRequest instanceof RequestWrapper) {
                ((RequestWrapper) originalRequest).addHeader("tenantId", tenantId);
            }
        } else if (request instanceof RequestWrapper) {
            // 处理普通请求
            ((RequestWrapper) request).addHeader("tenantId", tenantId);
        }
        // 其他类型的请求可以根据需要扩展
    }

    @Override
    public void init(FilterConfig filterConfig) {
        logger.info("HttpServletRequestFilter 初始化完成");
    }

    @Override
    public void destroy() {
        logger.info("HttpServletRequestFilter 销毁");
    }
}

private String getBodyString(ServletRequest request) {
    // 读取并保存请求体，支持重复读取
}

if (request instanceof StandardMultipartHttpServletRequest) {
    // 获取底层请求对象进行处理
}

@RestController
public class TestController {
    
    @GetMapping("/api/data")
    public ResponseEntity<?> getData(HttpServletRequest request) {
        // 获取自定义的 tenantId Header
        String tenantId = request.getHeader("tenantId");
        
        // 使用 tenantId 进行业务处理
        List<Data> result = dataService.getDataByTenant(tenantId);
        
        return ResponseEntity.ok(result);
    }
}