如何在 HandlerInterceptorAdapter 中添加 HttpServletRequest 标头？

Question

我正在尝试在我的请求中添加一个 Authorization 标头，作为我们切换环境时的临时解决方法。 我试图在扩展 HandlerInterceptorAdapter 的拦截器中处理它。

我使用了这里创建的 MutableHttpServletRequest 类，以便能够将标头添加到请求中，但似乎没有任何方法可以实际修改拦截器中返回的请求。 有什么想法吗？

编辑：或者我必须在过滤器中执行此操作吗？

Answer 1

HttpServletRequest 类型对象是只读的，为此您应该：

-> 创建一个扩展 HttpServletRequestWrapper 的类（添加一些行为，装饰器模式）

final public class MutableHttpServletRequest extends HttpServletRequestWrapper {

    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) {
        String headerValue = customHeaders.get(name);

        if (headerValue != null){
            return headerValue;
        }
        return ((HttpServletRequest) getRequest()).getHeader(name);
    }

    public Enumeration<String> getHeaderNames() {
        Set<String> set = new HashSet<String>(customHeaders.keySet());

        @SuppressWarnings("unchecked")
        Enumeration<String> e = ((HttpServletRequest) getRequest()).getHeaderNames();
        while (e.hasMoreElements()) {
            String n = e.nextElement();
            set.add(n);
        }
        return Collections.enumeration(set);
    }
}

-> 创建您的过滤器类

public class CustomGatewayFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        MutableHttpServletRequest mutableRequest = new MutableHttpServletRequest(req);
        mutableRequest.putHeader("referer", "custom value");
        chain.doFilter(mutableRequest, response);
    }
}

-> 并在您的配置类中添加

 .and().addFilterAfter(new CustomGatewayFilter(), ConcurrentSessionFilter.class)

Answer 2

public class YourInterceptor extends HandlerInterceptorAdapter {    

    @Override
    public boolean preHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler) throws Exception {
        SomeModel model = new SomeModel();
        request.setAttribute("someValue", model );
        request.addHeader("xxx","asecret");

        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request,
            HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {
        //...
         response.addHeader("dummy-header, "dummy-value");
    }

    @Override
    public void afterCompletion(HttpServletRequest request,
            HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        SomeModel model = (Long) request.getAttribute("someValue");

    }

}