解决java拦截器获取POST入参导致@RequestBody参数丢失问题

/**
 * @description: 获取流并将想要的结果通过拼接返回
 **/
public class HttpRequestHelper {
    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();
    }
}

/**
 * @description: 防止流丢失
 **/
public class MyRequestWrapper extends HttpServletRequestWrapper {
    private final byte[] body;

    public MyRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        //返回参数字节数组
        body = HttpRequestHelper.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) {

            }
        };
    }

}

/**
 * @description: 使用过滤器处理流，将当前流放到一个新的request对象中
 **/
public class HttpServletRequestFilter 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 MyRequestWrapper((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 {

    }
}

//放到继承HandlerInterceptor的类下的preHandle方法中指定业务位置就行啦，这里读出来的string，
//这里我处理为一个json(就是入参对象的各个字段和字段值)，方便操作
//构造函数的httpServletRequest参数是preHandle方法的request入参
JSONObject.parseObject(HttpRequestHelper.getBodyString(httpServletRequest));

    @Bean
    public FilterRegistrationBean httpServletRequestReplacedRegistration() {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        //把过滤器大哥安放到副驾上
        registration.setFilter(new HttpServletRequestFilter());
        registration.addUrlPatterns("/*");
        registration.addInitParameter("paramName", "paramValue");
        registration.setName("httpServletRequestFilter");
        registration.setOrder(1);
        return registration;
    }