导致 POST 请求正文变空的过滤器

Question

我正在使用 HMAC 身份验证过滤器。当我访问我的 POST 请求正文时，在过滤器中，我能够在其中获取 XML。当我尝试访问控制器中的 XML 时，我得到一个空字符串。过滤器中的 xmlString 给出正确的 XML 但控制器中的 xmlString 给出空白字符串。我正在使用 Spring MVC。

我的过滤器是：

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        HttpServletResponse httpResponse = (HttpServletResponse) response;

        String authorisation = httpRequest.getHeader("authorization");
        String accessKeyId = authorisation.split(":")[0].split(" ")[1];
        String signature = authorisation.split(":")[1];
        String secretAccessKey = getSecretAccessKey(accessKeyId);

        InputStream xmlStream = httpRequest.getInputStream();
        String xmlString = IOUtils.toString(xmlStream, "UTF-8");
        String encodedXml = new String();
        try {
            encodedXml = HMACEncoder.calculateHMAC(xmlString, secretAccessKey);
        } catch (SignatureException e) {
            e.printStackTrace();
        }
        if (!signature.equals(encodedXml))
            httpResponse.sendError(HttpServletResponse.SC_UNAUTHORIZED);
        else
            chain.doFilter(request, response);
    }

我的控制器是：

@RequestMapping(value = "/user", method = RequestMethod.POST)
public String fetchUserString(HttpServletRequest request) {
    InputStream xml = null;
    String xmlString = null;
    try {
        xml = request.getInputStream();
        xmlString = IOUtils.toString(xml, "UTF-8");
    } catch (IOException e) {
        e.printStackTrace();
    }
    return xmlString;
}

Answer 1

不能读取流两次，在filter中注释代码，在controller中只读。

Answer 2

正如 praki 所建议的，我将 XML 放在请求属性中，在我的控制器中，我从请求属性中获取它，然后将 XML 放在 ModelAttribute 中。这是我的代码：

我的过滤器：

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest httpRequest = (HttpServletRequest) request;
    HttpServletResponse httpResponse = (HttpServletResponse) response;
    if (httpRequest.getMethod().equalsIgnoreCase("POST")) {    
        String authorisation = httpRequest.getHeader("authorization");
        String accessKeyId = authorisation.split(":")[0].split(" ")[1];
        String signature = authorisation.split(":")[1];
        String secretAccessKey = getSecretAccessKey(accessKeyId);    
        ServletInputStream servletStream = httpRequest.getInputStream();
        String xmlString = IOUtils.toString(servletStream);
        String encodedXml = new String();
        try {
            encodedXml = HMACEncoder.calculateHMAC(xmlString, secretAccessKey);
        } catch (SignatureException e) {
            e.printStackTrace();
        }
        httpRequest.setAttribute("content", xmlString);
        if (!signature.equals(encodedXml))
            httpResponse.sendError(HttpServletResponse.SC_UNAUTHORIZED);
        else
            chain.doFilter(request, response);
    } else
        chain.doFilter(request, response);
}

和我的控制器：

@RequestMapping(value = "/add", method = RequestMethod.POST, produces = "application/xml")
public @ResponseBody Catalog addCatalog(@ModelAttribute("catalog") Catalog catalog) {
    logger.info("In addCatalog with " + catalog);
    catalog.getHeader().setOrganizationId(IConstant.ORGANIZATION_ID_BSL);
    try {
        catalog = catalogService.addCatalogIntegration(catalog);
    } catch (Exception e) {
        e.printStackTrace();
    }
    logger.info("Returning from addCatalog with " + catalog);
    return catalog;
}

@ModelAttribute("catalog")
private Catalog getCatalog(HttpServletRequest request) throws Exception {
    Catalog catalog = new Catalog();
    try {
        String xml = (String) request.getAttribute("content");
        if (xml != null) {
            JAXBContext jaxbContext = JAXBContext.newInstance(Catalog.class);
            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            catalog = (Catalog) unmarshaller.unmarshal(new StringReader(xml));
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return catalog;
}

导致 POST 请求正文变空的过滤器

Filter causing POST Request Body to become empty

java

spring-mvc

request

servlet-filters