SpringBoot之HandlerInterceptor-IO

SpringBoot之HandlerInterceptor-IOE Stream close

简要说明下SpringBoot的使用HandlerInterceptor 通过request.getInputStream()获取数据报Stream closed异常分析解决。

代码实例：

@Component
public class AmsInterceptor implements HandlerInterceptor {

    private static final Logger LOGGER = LoggerFactory.getLogger(AmsInterceptor.class);

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

        HandlerMethod method = (HandlerMethod) handler;
        String cn = method.getBean().getClass().getName();
        String mn = method.getMethod().getName();
        String bodyString = getBodyString(request);
        LOGGER.info("preHandle : [{}]#[{}]#[{}]", cn, mn, bodyString);
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        LOGGER.info("postHandle : [{}]", request.getRequestURI());
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        LOGGER.info("afterCompletion : [{}]", request.getRequestURI());
    }

}
public static String getBodyString(HttpServletRequest request) throws IOException {
    StringBuilder sb = new StringBuilder();
    InputStream inputStream = null;
    BufferedReader reader = null;
    try {
        inputStream = request.getInputStream();
        reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")));
        String line = "";
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (inputStream != null) {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (reader != null) {
            try {
                reader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return sb.toString();
}

• String bodyString = getBodyString(request); 我们在拦截器中通过request.getInputStream();获取到body中的信息后，之后在controller中使用了@RequestBody注解获取参数报如下错误：

I/O error while reading input message; nested exception is java.io.IOException: Stream closed
org.springframework.http.converter.HttpMessageNotReadableException: I/O error while reading input message; nested exception is java.io.IOException: Stream closed
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:229)
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:150)
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:128)
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)
    at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:158)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:128)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    at 
    ...

出现原因：

spring boot项目，RequestBody里数据，只能通过流的方式获取，而在aop里获取了，在Controller里使用@RequestBody注解再获取就报

I/O error  while reading input message; nested exception is java.io.IOException: Stream closed

这个流只能用一次，用过之后，就不能再取数据了。

解决方案

先读取流，然后在将流写进去，下次就可以再读取流了。

实现

1. 重写 HttpServletRequestWrapper

public class ReHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] bodyBuf;

    public ReHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        bodyBuf = HttpHelper.getBodyString(request).getBytes(Charset.forName("UTF-8"));
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {

        final ByteArrayInputStream stream = new ByteArrayInputStream(bodyBuf);

        return new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }

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

            @Override
            public void setReadListener(ReadListener readListener) {

            }

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

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }
}

2. 将重写 HttpServletRequestWrapper通过过滤器重新写入

@Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;

        String uri = request.getRequestURI();

        long start = System.currentTimeMillis();
        LOGGER.info("请求地址 : [{}]", uri);

        ServletRequest requestWrapper;
        if (servletRequest instanceof HttpServletRequest) {
            requestWrapper = new ReHttpServletRequestWrapper((HttpServletRequest) servletRequest);
            if (requestWrapper != null) {
                servletRequest = requestWrapper;
            }
        }

        filterChain.doFilter(servletRequest, servletResponse);

        long end = System.currentTimeMillis();

        LOGGER.info("请求地址 : [{}], 耗时 : [{}] ms", uri, (end - start));
    }

这样我们就可以在Interceptor中通过request.getInputStream();获取到body中的信息