【SpringBoot8】HandlerInterceptor拦截器的使用 ——自@RequestBody获取请求参数解决java.io.IOException: Stream closed

淩亂°似流年 2024-03-26 13:48 24阅读 0赞

现在开发的项目是基于SpringBoot的maven项目，拦截器的使用很多时候是必不可少的，当有需要需要你对body中的值进行校验，例如加密验签、防重复提交、内容校验等等。  
当你开开心心的在拦截器中通过request.getInputStream();获取到body中的信息后，你会发现你在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 org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:96)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    	at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:110)
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

IO流关闭只能读取一次，接下来我们就开始解决这个BUG，有两种大的方向：

*  这个需求咱不做了，特么有本事就把东西都放在请求头里面传过来；
 *  解决流只能读取一次的问题，让它可以被多次重复读取；

最简单的方案就是 先读取流，然后在将流写进去就行了

### 引入包 ###

<dependency>
    	<groupId>org.apache.tomcat.embed</groupId>
    	<artifactId>tomcat-embed-core</artifactId>
    	<version>8.5.15</version>
    </dependency>

新建HttpHelper （用于读取Body）

package com.xxx.util.core.filter.request;
    
    import javax.servlet.http.HttpServletRequest;
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.nio.charset.Charset;
    
    public class HttpHelper {
        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();
        }
    }

新建RequestReaderHttpServletRequestWrapper（防止流丢失）

package com.xxx.util.core.filter.request;
    
    import java.io.BufferedReader;
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.nio.charset.Charset;
    
    import javax.servlet.ReadListener;
    import javax.servlet.ServletInputStream;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletRequestWrapper;
    
    public class RequestReaderHttpServletRequestWrapper extends HttpServletRequestWrapper{
    
        private final byte[] body;
    
        public RequestReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
            super(request);
            body = HttpHelper.getBodyString(request).getBytes(Charset.forName("UTF-8"));
        }
    
        @Override
        public BufferedReader getReader() throws IOException {
            return new BufferedReader(new InputStreamReader(getInputStream()));
        }
    
        @Override
        public ServletInputStream getInputStream() throws IOException {
    
            final ByteArrayInputStream bais = new ByteArrayInputStream(body);
    
            return new ServletInputStream() {
    
                @Override
                public int read() throws IOException {
                    return bais.read();
                }
    
                @Override
                public boolean isFinished() {
                    return false;
                }
    
                @Override
                public boolean isReady() {
                    return false;
                }
    
                @Override
                public void setReadListener(ReadListener readListener) {
    
                }
            };
        }
    }

### 新建HttpServletRequestReplacedFilter(过滤器) ###

package com.xxx.util.core.filter.request;
    
    
    import javax.servlet.*;
    import javax.servlet.http.HttpServletRequest;
    import java.io.IOException;
    
    
    public class HttpServletRequestReplacedFilter implements Filter {
        @Override
        public void destroy() {
    
        }
    
        @Override
        public void doFilter(ServletRequest request, ServletResponse response,
                             FilterChain chain) throws IOException, ServletException {
            ServletRequest requestWrapper = null;
            if(request instanceof HttpServletRequest) {
                requestWrapper = new RequestReaderHttpServletRequestWrapper((HttpServletRequest) request);
            }
            //获取请求中的流如何，将取出来的字符串，再次转换成流，然后把它放入到新request对象中。
            // 在chain.doFiler方法中传递新的request对象
            if(requestWrapper == null) {
                chain.doFilter(request, response);
            } else {
                chain.doFilter(requestWrapper, response);
            }
        }
    
        @Override
        public void init(FilterConfig arg0) throws ServletException {
    
        }
    }

最后我们只需要在Application.java中加上如下代码注入过滤器即可

@Bean
    	public FilterRegistrationBean httpServletRequestReplacedRegistration() {
    		FilterRegistrationBean registration = new FilterRegistrationBean();
    		registration.setFilter(new HttpServletRequestReplacedFilter());
    		registration.addUrlPatterns("/*");
            registration.addInitParameter("paramName", "paramValue");
    		registration.setName("httpServletRequestReplacedFilter");
    		registration.setOrder(1);
    		return registration;
    	}

如下代码即可在拦截其中获取body且保证了controller中依旧可以再次获取

HttpHelper.getBodyString(request);