HttpServletRequest增加消息头

本是古典何须时尚 2022-05-15 14:04 415阅读 0赞

由于在请求中请求域的属性在请求转发，路由等过程中，请求域的值会丢失，，在项目项目中使用请求头来传递信息，但是HttpRequest并没有实现增加请求头的方法，所以找到他的子类来实现

class MutableHttpServletRequest extends HttpServletRequestWrapper {
        // holds custom header and value mapping
        private final Map<String, String> customHeaders;
     
        public MutableHttpServletRequest(HttpServletRequest request){
            super(request);
            this.customHeaders = new HashMap<String, String>();
        }
        
        public void putHeader(String name, String value){
            this.customHeaders.put(name, value);
        }
     
        public String getHeader(String name) {
            // check the custom headers first
            String headerValue = customHeaders.get(name);
            
            if (headerValue != null){
                return headerValue;
            }
            // else return from into the original wrapped object
            return ((HttpServletRequest) getRequest()).getHeader(name);
        }
     
        public Enumeration<String> getHeaderNames() {
            // create a set of the custom header names
            Set<String> set = new HashSet<String>(customHeaders.keySet());
            
            // now add the headers from the wrapped request object
            @SuppressWarnings("unchecked")
            Enumeration<String> e = ((HttpServletRequest) getRequest()).getHeaderNames();
            while (e.hasMoreElements()) {
                // add the names of the request headers into the list
                String n = e.nextElement();
                set.add(n);
            }
     
            // create an enumeration from the set and return
            return Collections.enumeration(set);
        }
    }

使用：

public class SecurityFilter implements javax.servlet.Filter {
     
        @Override
        public void destroy() {
            
        }
     
        @Override
        public void doFilter(ServletRequest request, ServletResponse response,
                FilterChain chain) throws IOException, ServletException {
            HttpServletRequest req = (HttpServletRequest) request;
            MutableHttpServletRequest mutableRequest = new MutableHttpServletRequest(req);
            ...
            mutableRequest.putHeader("x-custom-header", "custom value");
            chain.doFilter(mutableRequest, response);
        }
     
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
            
        }
    }

但是项目中我使用的SpringCloud ZUUL中使用这样 的方式失败：

@Component
    public class AccessFilter extends ZuulFilter {
        private  Logger log = LoggerFactory.getLogger(AccessFilter.class);
    
        @Autowired
        private VerificationHelper helper;
    
        private  BufferedReader reader=null;
        @Autowired
        private KeyAndFrequencyService service;
    
        @Autowired
        private ZuulTest zuulTest;
    
        @Autowired
        private PermissionHandler permissionHandler;
    
    
    
    
        @Override
        public String filterType() {
            //前置过滤器
            return "pre";
        }
    
        @Override
        public int filterOrder() {
            //优先级，数字越大，优先级越低
            return 0;
        }
    
        @Override
        public boolean shouldFilter() {
            //是否执行该过滤器，true代表需要过滤
            return true;
        }
    
    
        @Override
        public Object run() {
    
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletRequest request = ctx.getRequest();
    
    
            try {
    
                permissionHandler.setTokenExpireTime(200000000);
                String type = request.getHeader("type");
                zuulTest.say();
                System.out.println("......................................................");
                if (type == null) {
    
                    System.out.println("......................................................验证1");
    
                    Object object = helper.AccessZuul(request, ctx);
                    return object;
    
    
                } else {
    
                    System.out.println("......................................................验证2");
    
    
    
    
    
                    PermissionResult result=permissionHandler.check(request);
                    System.out.println(result);
                    if(result.isState()){
    
    
    
              
    MutableHttpServletRequest  mutRequest=new MutableHttpServletRequest (request)；
                         //增加头部信息
                        DasAccountInfo accountInfo= permissionHandler.GetDasAccountInfoById(Integer.parseInt(result.getUserId()));
                        
                        mutRequest.putHeader("dasAccountInfo", JSON.toJSONString(disablePropertyName()))                   ;RequestContext.getCurrentContext().setRequest(mutRequest);
    
    
                        ctx.setSendZuulResponse(true);// 对该请求进行路由
                        ctx.setResponseStatusCode(200);
                        ctx.set("isSuccess", true);
    
                    }else{
                        ctx.setSendZuulResponse(false);// 过滤该请求，不对其进行路由
                        ctx.setResponseStatusCode(401);// 返回错误码
                        ctx.setResponseBody("{\"code\":0,\"result\":\"网关验证失败!验证方式为2\"}");// 返回错误内容
                        ctx.set("isSuccess", false);
                    }
    
                }
    
            }catch (Exception e){
                e.printStackTrace();
                log.error("网关报错！！！",e.fillInStackTrace());
            }
    
               return null;
        }

使用zuul网关的自带的设置请求头的方法，在网关中设置的请求头可以被路由下面的服务获取到:

ctx.getZuulRequestHeaders().put("dasAccountInfo", JSON.toJSONString(disablePropertyName()));

参考：  
[https://blog.csdn.net/wangjia55/article/details/51712574/][https_blog.csdn.net_wangjia55_article_details_51712574]

[https_blog.csdn.net_wangjia55_article_details_51712574]: https://blog.csdn.net/wangjia55/article/details/51712574/