java - 使用 HttpServletRequestWrapper 进行复制后缺少所需的请求正文

Question

在我的项目中，我有一组 api 调用，它们应该通过某些常见的验证集进行过滤。在这种情况下，我必须在请求到达 REST Controller 之前拦截请求，读取请求正文，进行验证并在请求通过验证时将其传递给 Controller ​​。

自 HttpServletRequest不能反序列化多次，我使用了 HttpServletRequestWrapper复制实际请求。使用它制作的副本，我进行验证。

以下是拦截请求的配置类。

public class InterceptorConfig extends WebMvcConfigurerAdapter {

     @Autowired     
     CustomInterceptor customInterceptor;

     @Override  
     public void addInterceptors(InterceptorRegistry registry) { 
        registry.addInterceptor(customInterceptor).addPathPatterns("/signup/**");

     }   
}

这是我的 preHandle里面的方法 CustomInterceptor扩展 HandlerInterceptorAdaptor 的类

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

    ServletRequest copiedRequest = new HttpRequestWrapper(request);

    Map<String, Object> jsonMap = mapper.readValue(copiedRequest.getInputStream(), Map.class);

    if(jsonMap.containsKey("userId")){
        long userId = jsonMap.get("userId");
        MyClass myObject= myAutowiredService.getMyObject(userId);
        if(myObject == null){
            response.setStatus(HttpStatus.SC_NOT_ACCEPTABLE);
            return false;
        } 
        // some more validations which end up returning false if they are met
    }
    return true;
}

这是我的 HttpRequestWrapper

public class HttpRequestWrapper extends HttpServletRequestWrapper {

    private byte[] requestBody;

    public HttpRequestWrapper(HttpServletRequest request) throws IOException{
        super(request);

        try {
            requestBody = IOUtils.toByteArray(request.getInputStream());
        } catch (IOException ex) {
            requestBody = new byte[0];
        }
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {

        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(requestBody);

        return new ServletInputStream() {

            @Override
            public boolean isFinished() {
                return byteArrayInputStream.available() == 0;
            }

            @Override
            public boolean isReady() {
                return true;
            }

            @Override
            public void setReadListener(ReadListener listener) {
                throw new RuntimeException("Not implemented");
            }

            public int read () throws IOException {
                return byteArrayInputStream.read();
            }
        };
    }

}

现在一切就绪。现在，当我向任何具有 /signup/** 模式的 url 发送请求时，所有验证都正常进行。但是，一旦请求命中 Controller 方法，就会弹出错误，指出请求正文不可用。

Required request body is missing: public com.mypackage.myResponseObject com.mypackage.myController.myControllerMethod(com.mypackage.myDTO)

我正在努力寻找原因以及解决问题的方法。我在 RequestWrapper 类中做错了什么吗？或缺少什么？

帮我解决这个问题。

谢谢!

Answer 1

问题似乎是您正在使用拦截器来读取 HttpServletRequest的 InputStream并将其包裹在 HttpRequestWrapper 中但包装器永远不会返回。

我认为你应该使用 Filter

public class CustomFilter extends OncePerRequestFilter {
    public void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        ServletRequest copiedRequest = new HttpRequestWrapper(request);

        Map<String, Object> jsonMap = mapper.readValue(copiedRequest.getInputStream(), Map.class);

        if(jsonMap.containsKey("userId")){
            long userId = jsonMap.get("userId");
            MyClass myObject= myAutowiredService.getMyObject(userId);
            if(myObject == null){
                response.setStatus(HttpStatus.SC_NOT_ACCEPTABLE);
                //return false;
            } 
            // some more validations which end up returning false if they are met
         }

         filterChain.doFilter(copiedRequest, (ServletResponse) response);
    }
}

您需要在 web.xml 中使用此过滤器或 WebApplicationInitializer