SpringBoot怎么实现多次读取流

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1). 存在问题
流只能读取一次

2). 目标
多次读取流

3). 解决方法
创建包装类

4). RequestWrapper

package com.mazaiting.redeye.wrapper; import com.mazaiting.redeye.utils.StreamUtil;import lombok.extern.slf4j.Slf4j;import org.slf4j.Logger;import org.slf4j.LoggerFactory; import javax.servlet.ReadListener;import javax.servlet.ServletInputStream;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.Charset; /*** * @author mazaiting * @date 2019-06-27 * @decription HttpServletRequest 包装器 * 解决: request.getInputStream()只能读取一次的问题 * 目标: 流可重复读 */@Slf4jpublic class RequestWrapper extends HttpServletRequestWrapper {    /**     * 日志     */    private static final Logger mLogger = LoggerFactory.getLogger(RequestWrapper.class);     /**     * 请求体     */    private String mBody;     public RequestWrapper(HttpServletRequest request) {        super(request);        // 将body数据存储起来        mBody = getBody(request);    }     /**     * 获取请求体     * @param request 请求     * @return 请求体     */    private String getBody(HttpServletRequest request) {        try {            return StreamUtil.getString(request.getInputStream());        } catch (IOException e) {            mLogger.debug(e.getMessage());            throw new RuntimeException(e);        }    }     /**     * 获取请求体     * @return 请求体     */    public String getBody() {        return mBody;    }     @Override    public BufferedReader getReader() throws IOException {        return new BufferedReader(new InputStreamReader(getInputStream()));    }     @Override    public ServletInputStream getInputStream() throws IOException {        // 创建字节数组输入流        final ByteArrayInputStream bais = new ByteArrayInputStream(mBody.getBytes(Charset.defaultCharset()));         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 bais.read();            }        };    }}

5).设置过滤器(必须)

@Component@WebFilter(filterName = "HttpServletRequestFilter", urlPatterns = "/")@Order(10000)public class HttpServletRequestFilter 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() {     }}

6). 使用

/*** * * @author mazaiting * @date 2019-06-26 * @decription Session 拦截器 */public class SessionInterceptor implements HandlerInterceptor {     /**     * 日志     */    private static final Logger mLogger = LoggerFactory.getLogger(SessionInterceptor.class);     @Override    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {        mLogger.debug("SessionInterceptor");        // 获取地址        String url = request.getRequestURL().toString();        mLogger.debug("url: " + url);        // 获取 session        HttpSession session = request.getSession();        String id = session.getId();        mLogger.debug("sessionId: " + id);        String requestMethod = request.getMethod();        mLogger.debug("requestMethod: " + requestMethod);        String servletPath = request.getServletPath();        mLogger.debug("servletPath: " + servletPath);         if (isJson(request)) {            String body = new RequestWrapper(request).getBody();            mLogger.debug("body: " + body);        }         return true;    }     /**     * 判断本次请求的数据类型是否为json     *     * @param request request     * @return true: 是 JSON 数据; false: 非 json 数据     */    private boolean isJson(HttpServletRequest request) {        if (request.getContentType() != null) {            return request.getContentType().equals(MediaType.APPLICATION_JSON_VALUE) ||                    request.getContentType().equals(MediaType.APPLICATION_JSON_UTF8_VALUE);        }         return false;    }}

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