解決在Filter中讀取Request中的流後, 而後再Control中讀取不到的作法

前段時間在開發中遇到這個問題，在網上搜索找到了解決方法， 在Filter中的處理

public class SessionFilter extends GenericFilterBean {
    private static Logger log = LoggerFactory.getLogger(SessionFilter.class);

    @Override
    public void doFilter(ServletRequest req, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        
        // 爲了不這次讀取request流後面control讀取不到
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletRequest requestWrapper = new BodyReaderHttpServletRequestWrapper(request);

       。。。業務代碼
            if(null == requestWrapper) {
                chain.doFilter(request, response);
            } else {
                chain.doFilter(requestWrapper, response);
            }
        }

    }

}

package com.szkingdom.jros.va.util;

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;
import java.util.Enumeration;

/**
 * Created by zengh on 2017/5/17.
 */
public class BodyReaderHttpServletRequestWrapper extends  HttpServletRequestWrapper {

    private final byte[] body;

    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        Enumeration e = request.getHeaderNames();
        while (e.hasMoreElements()) {
            String name = (String) e.nextElement();
            String value = request.getHeader(name);
        }
        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 String getHeader(String name) {
        return super.getHeader(name);
    }

    @Override
    public Enumeration<String> getHeaderNames() {
        return super.getHeaderNames();
    }

    @Override
    public Enumeration<String> getHeaders(String name) {
        return super.getHeaders(name);
    }
}

package com.szkingdom.jros.va.util;

import javax.servlet.ServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.Charset;

/**
 * Created by zengh on 2017/5/17.
 */
public class HttpHelper {
    /**
     * 獲取請求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();
    }
}