无法正确读取拦截器中的请求主体 - Spring BOOT 2.0.4

Question

我在拦截器中读取请求正文时遇到问题。两者getReader()都会getInputStream()造成问题。我的拦截器：

public class MyInterceptor extends HandlerInterceptorAdapter {
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exception)
        throws Exception {
    // TODO Auto-generated method stub

}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
        throws Exception {
    // TODO Auto-generated method stub
}
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

    String requestBody = httpRequest.getReader().lines().collect(Collectors.joining(System.lineSeparator()));

//or
// String requestBody = new BufferedReader(new InputStreamReader(httpRequest.getInputStream()))
//                .lines().collect(Collectors.joining("\n"));
//some logic...
    return true;
}

这两种方法都失败了，因为 spring 可能在内部某处使用了此类资源。第一个原因是java.lang.IllegalStateException: getReader() 已为此请求调用，并且缺少其他必需的请求正文：org.springframework.http.ResponseEntity ...

我尝试了一些包装器的解决方法，但没有效果。我认为这是因为我无法像过滤器一样传递包装器（我不想使用过滤器，因为我有常见的异常管理器（@ControllerAdvice）。

这是一个已知的问题？有什么解决方法吗？

Answer 1

最后我想通了，所以我将在这里为其他人留下一些简单但有用的建议。我使用了请求包装器，但为了使其正常工作，我添加了一个具有最高顺序的过滤器，以在执行拦截器之前将每个请求包装到包装器中。现在它工作得很好;)这是最重要的代码 - 过滤器将每个请求包装到多读包装器中（拦截器看起来几乎与上面相同，包装器不是我发明的，在堆栈上找到的，我发现它是最清晰和可读的）：

import lombok.SneakyThrows;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.stream.Collectors;

@Component
@Order(Ordered.HIGHEST_PRECEDENCE)
public class GlobalWrapFilter implements Filter {


    @Override
    @SneakyThrows
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) {
        MultiReadRequest wrapper = new MultiReadRequest((HttpServletRequest) request);
        chain.doFilter(wrapper, response);
    }

    @Override
    public void destroy() {
    }

    class MultiReadRequest extends HttpServletRequestWrapper {

        private String requestBody;

        @SneakyThrows
        public MultiReadRequest(HttpServletRequest request) {
            super(request);
            requestBody = request.getReader().lines().collect(Collectors.joining(System.lineSeparator()));
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {
            final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(requestBody.getBytes());
            return new ServletInputStream() {
                @Override
                public boolean isFinished() {
                    return byteArrayInputStream.available() == 0;
                }

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

                @Override
                public void setReadListener(ReadListener readListener) {

                }

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

        @Override
        @SneakyThrows
        public BufferedReader getReader() {
            return new BufferedReader(new InputStreamReader(this.getInputStream(), StandardCharsets.UTF_8));
        }
    }
}