java.lang.IllegalStateException: getReader() 已为当前请求调用后无法调用 getInputStream()

Question

我写了拦截器：

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    log.info("[pre-handle] method: {}\tURL: {}", request.getMethod(), request.getRequestURL());
    if (HttpMethod.POST.name().equals(request.getMethod())) {
        log.info(request.getReader().lines().collect(Collectors.joining()));
    }
    return true;
}

但是当我尝试调用控制器时，抛出异常：

java.lang.IllegalStateException: Cannot call getInputStream() after getReader() has already been called for the current request

据我了解，调用 getReader() 会关闭 InputStream 并且控制器不会收到任何内容。如何解决？

Answer 1

要多次读取请求，您需要在第一次读取之前缓存您的请求。更多信息可以阅读 here.

Spring MVC 提供了 ContentCachingRequestWrapper class。它是原始 HttpServletRequest 对象的包装器。

要使用它，我们必须首先创建一个包装原始 HttpServletRequest 的 Web 过滤器：

@Component
public class CachingRequestBodyFilter extends GenericFilterBean {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
      throws IOException, ServletException {
        HttpServletRequest currentRequest = (HttpServletRequest) servletRequest;
        ContentCachingRequestWrapper wrappedRequest = new ContentCachingRequestWrapper(currentRequest);
        chain.doFilter(wrappedRequest, servletResponse);
    }

之后你可以在你的拦截器中使用ContentCachingRequestWrapper的getContentAsByteArray方法获取byte[]内容

java.lang.IllegalStateException: getReader() 已为当前请求调用后无法调用 getInputStream()

java.lang.IllegalStateException: Cannot call getInputStream() after getReader() has already been called for the current request

java

interceptor