解决在Filter中读取Request中的流后, 然后再Control中读取不到的做法

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摘要: 大家知道, StringMVC中@RequestBody是读取的流的方式, 如果在之前有读取过流后, 发现就没有了.

我们来看一下核心代码: filter中主要做的事情, 就是来校验请求是否合法, 是否有篡改过值.

@Override

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

        if (Boolean.valueOf(authentication)) {

            HttpServletRequest httpServletRequest = (HttpServletRequest) request;

            if (BasicdataCommonsConstant.POST.equalsIgnoreCase(httpServletRequest.getMethod())) {

                // 防止流读取一次后就没有了, 所以需要将流继续写出去

                ServletRequest requestWrapper = new BodyReaderHttpServletRequestWrapper(httpServletRequest);

                String body = HttpHelper.getBodyString(requestWrapper);

                if (StringUtils.isBlank(body)) {

                    LOGGER.error("非法请求, 没有APP_KEY, APP_SECRET");

                    OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_FROMTYPE)));

                    return;

                }

                Map<String, String> parameters = gson.fromJson(body, new TypeToken<Map<String, String>>() {

                }.getType());

                String APP_KEY = parameters.get("appKey");

                String APP_SECRET = parameters.get("appSecret");

                TAuthUser authUser = authUserMap.get(APP_KEY);

                if (authUser == null) {

                    LOGGER.error("非法请求, 没有APP_KEY, APP_SECRET");

                    OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_FROMTYPE)));

                    return;

                } else if (StringUtils.isBlank(APP_SECRET)) {

                    LOGGER.error("非法请求, APP_SECRET为空, user={}", gson.toJson(authUser));

                    OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_FROMTYPE_AND_KEY_CANNT_BE_NULL)));

                    return;

                } else if (!APP_SECRET.equals(authUser.getAppSecret())) {

                    LOGGER.error("非法请求: 没有APP_KEY, APP_SECRET不匹配. user={}, password={}, name={}", APP_KEY, APP_SECRET, authUser.getName());

                    OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_ILLEGAL_KEY)));

                    return;

                }

                String SIGNATURE = parameters.get("signature");

                // 对参数进行签名

                String md5 = SignatureUtil.decryptSignature(parameters);

                if (!md5.equals(SIGNATURE)) {

                    LOGGER.error("非法请求, signature ={}", SIGNATURE);

                    OutWriterUtil.outJson(response, gson.toJson(new Response(ErrorCode.AUTH_ERROR_SIGNATURE_ERROR)));

                    return;

                }

                threadLocalUser.setAuthUser(authUser);

                chain.doFilter(requestWrapper, response);

            }

        }

        chain.doFilter(request, response);

    }

大家都知道, 流只能读一次, 读了就没有了, 为了后面的代码还能够取得流, 我们应该还需要将其写出去才行.

所以, 我新建立了一个类. 看代码:

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;

/**

 * Created with antnest-platform

 * User: chenyuan

 * Date: 12/31/14

 * Time: 8:49 PM

 */

public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] body;

    public BodyReaderHttpServletRequestWrapper(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) {

            }

        };

    }

}

import javax.servlet.ServletRequest;

import javax.servlet.http.HttpServletRequest;

import java.io.BufferedInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

/**

 * Created with antnest-platform

 * User: chenyuan

 * Date: 12/24/14

 * Time: 10:39 AM

 */

public class HttpHelper {

    /**

     * 获取请求Body

     *

     * @param request

     * @return

     */

    public static String getBodyString(ServletRequest request) {

        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();

    }

}