Java-解决发送Post请求报Stream closed问题

谁践踏了优雅 2023-10-02 18:33 15阅读 0赞

springboot项目还是ssm等java常用框架都会有这样的问题,解决办法通用

### 问题场景 ###

前端发送Post请求，,前端返回400 Bad Request,后端Controller层接口也没进去,然后我就开始分析,是啥问题,我通过后端控制台发现HttpMessageNotReadableException 提示信息,这个不是读取请求的消息错误发生的异常吗? 然后我通过IDEA 的DEBUG拦截这个异常发生的位置,然后将相关的代码从新走了一遍发现在  
`AbstractMessageConverterMethodArgumentResolver->readWithMessageConverters`  
![在这里插入图片描述][e1f30a328cf141f69d184cc849af436d.png]  
EmptyBodyCheckingHttpInputMessage 是内部类  
![在这里插入图片描述][6a2732a900fd41b1a728029294b7bf17.png]  
控制台打印warn 信息如下:

org.springframework.http.converter.HttpMessageNotReadableException:  I/O error while reading input message; nested exception is java.io.IOException: Stream closed

#### 问题分析 ####

`这是因为有人在过滤器或者拦截器中对Request的请求体中的数据流读取了一遍导致的`,Springboot准备读取Body数据映射到接口的实体类参数时候失败,发现流已经没有内容了,因为在接口数据流传输使用的都是InputStream 这个流只能被读取一次

### 解决办法 ###

将InputStream 传输数据,缓存起来,保存到字符串中,之后用的时候将字符串转在转换为流,那么这个字符串就能持续的被复用了

**缓存数据**

package com.schemautils;
    
    /**
     * 解决获取post请求的请求体body只能读取一次问题
     */
    import com.alibaba.fastjson.JSONObject;
    
    import javax.servlet.ReadListener;
    import javax.servlet.ServletInputStream;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletRequestWrapper;
    import java.io.*;
    public class RequestWrapper extends HttpServletRequestWrapper {
        
    
        private final String body;
        public RequestWrapper(HttpServletRequest request) {
        
            super(request);
            StringBuilder stringBuilder = new StringBuilder();
            BufferedReader bufferedReader = null;
            InputStream inputStream = null;
            try {
        
             //防止未初始化body,我们手动初始化body ,内部会将body内容初始化到InputStream里
    	        request.getParameterMap();
    	        //然后在读取InputStream
    	       inputStream = request.getInputStream();
                if (inputStream != null) {
        
                    bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                    char[] charBuffer = new char[128];
                    int bytesRead = -1;
                    while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
        
                        stringBuilder.append(charBuffer, 0, bytesRead);
                    }
                } else {
        
                    stringBuilder.append("");
                }
            } catch (IOException ex) {
        
            } finally {
        
                if (inputStream != null) {
        
                    try {
        
                        inputStream.close();
                    }
                    catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
                if (bufferedReader != null) {
        
                    try {
        
                        bufferedReader.close();
                    }
                    catch (IOException e) {
        
                        e.printStackTrace();
                    }
                }
            }
            body = stringBuilder.toString();
        }
    
        @Override
        public ServletInputStream getInputStream() throws IOException {
        
            final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
            ServletInputStream servletInputStream = 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 byteArrayInputStream.read();
                }
            };
            return servletInputStream;
        }
    
        @Override
        public BufferedReader getReader() throws IOException {
        
            return new BufferedReader(new InputStreamReader(this.getInputStream()));
        }
    
    
        public JSONObject getBody() {
        
            return JSONObject.parseObject(this.body);
        }
    
    
    }

**添加过滤器并且配置缓存类**

package com.schemautils;
    
    
    import org.springframework.core.annotation.Order;
    import org.springframework.stereotype.Component;
    
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import javax.servlet.http.HttpServletRequest;
    import java.io.IOException;
    
    //获取请求中的流，将取出来的，再次转换成流，然后把它放入到新request对象中
    //必须保证在所有过滤器之前执行,否则就会出现问题(按照首字母进行过滤器优先级A>B>C)
    @WebFilter(filterName = "ACacheHttpServletRequestFilter", urlPatterns = "/")
    public class CacheHttpServletRequestFilter implements Filter {
        
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
        
    
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        
            ServletRequest requestWrapper = null;
            if(servletRequest instanceof HttpServletRequest) {
        
                requestWrapper = new RequestWrapper((HttpServletRequest) servletRequest);
            }
            //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(null == requestWrapper) {
        
                filterChain.doFilter(servletRequest, servletResponse);
            } else {
        
                filterChain.doFilter(requestWrapper, servletResponse);
            }
        }
    
        @Override
        public void destroy() {
        
    
        }
    }

**在启动类上开启扫描Filter注解**

@SpringBootApplication(scanBasePackages = "com")
    @ServletComponentScan //开启扫描Filter
    public class ApplicatioBoot {
        
    
        public static void main(String[] args) {
        
            SpringApplication.run(ApplicatioBoot.class,args);
        }
    
    }

![在这里插入图片描述][e2af4607da624cff9e7bf546663eaa91.gif]

点赞 -收藏-关注-便于以后复习和收到最新内容有其他问题在评论区讨论-或者私信我-收到会在第一时间回复如有侵权，请私信联系我感谢,配合,希望我的努力对你有帮助^\_^

![ceaefc422a4745479fc1e8cfd2bdb74e.jpg][]

[e1f30a328cf141f69d184cc849af436d.png]: https://img-blog.csdnimg.cn/e1f30a328cf141f69d184cc849af436d.png
[6a2732a900fd41b1a728029294b7bf17.png]: https://img-blog.csdnimg.cn/6a2732a900fd41b1a728029294b7bf17.png
[e2af4607da624cff9e7bf546663eaa91.gif]: https://img-blog.csdnimg.cn/e2af4607da624cff9e7bf546663eaa91.gif
[ceaefc422a4745479fc1e8cfd2bdb74e.jpg]: https://img-blog.csdnimg.cn/ceaefc422a4745479fc1e8cfd2bdb74e.jpg