请求日志——用于调试开发-蒲公英云

一、前言

在请求分发给具体的处理器之前，我们可以通过过滤器和拦截器来截取请求信息，但是藏于body中的参数确不能直接获取，因为在流对象中只允许一次性打开，这就好比你将桶里的水倒干净了，然后把桶交给别人。

常规的处理方案有两种：

   1、将流内容导入另一个流，然后将新的流传递
   2、通过mark()和reset()方法将流内容回流。

最初，我采用第二种方式，却发现依旧存在很多问题，比如mark长度难以确定，无法绕开servletRequest无法二次打开的设定。于是采用第一种办法。

二、如何复制请求流

package com.baye.common.core.filter;
import org.apache.commons.lang.StringUtils;
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;
/**
 * 复制请求,代替原有request传递给具体处理器
 *
 * @author sunyiran
 * @date 2018-11-27
 */
public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {
    /**
     * 利用body存储流内容
     */
    private final byte[] body;
    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        body = readBytes(request.getReader());
    }
    @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 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();
            }
        };
    }
    /**
     * 通过BufferedReader和字符编码集转换成byte数组
     *
     * @param br
     * @return
     * @throws IOException
     */
    private byte[] readBytes(BufferedReader br ) throws IOException {
        String str;
        StringBuilder retStr = new StringBuilder();
        while ((str = br.readLine()) != null) {
            retStr.append(str);
        }
        if (StringUtils.isNotBlank(retStr.toString())) {
            return retStr.toString().getBytes(Charset.forName("utf-8"));
        }
        return null;
    }
}

三、如何过滤请求

注意在主类上添加：@ServletComponentScan

package com.baye.common.core.filter;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;
/**
 * todo 上线时关闭
 * @author sunyiran
 * @date 2018-11-27
 */
@WebFilter(urlPatterns = "/*")
public class RequestLogFilter implements Filter{
    private static final Log logger = LogFactory.getLog("RequestLogdFilter");
    @Override
    public void destroy() {
    }
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        throws IOException, ServletException {
        ServletRequest requestWrapper = printRequestLog((HttpServletRequest) request);
        if (requestWrapper == null) {
            chain.doFilter(request,response);
        }
        chain.doFilter(requestWrapper, response);
    }
    @Override
    public void init(FilterConfig arg0)  {
    }
    /**
     * 打印请求详情
     * @param request
     * @return
     * @throws IOException
     */
    private ServletRequest printRequestLog(HttpServletRequest request) throws IOException {
        Map<String, String[]> params = request.getParameterMap();
        String requestUri = request.getRequestURI();
        String ip = getRemoteHost(request);
        StringBuilder msg = new StringBuilder(
            "\r\n" + ip + "-请求：" + requestUri + "-->[" + request.getMethod() + "]\r\n");
        Enumeration<String> headers = request.getHeaderNames();
        String key = null;
        while (headers.hasMoreElements()) {
            key = headers.nextElement();
            msg.append("\t").append(key).append(":\t\t").append(request.getHeader(key)).append("\r\n");
        }
        msg.append("---------------------------------------------------------------------------------\r\n");
        //如果传递方式为RequestParam
        if (params != null && !params.isEmpty()) {
            msg.append("\tRequestParam:");
            for (Map.Entry<String, String[]> item : params.entrySet()) {
                msg.append("\t").append(item.getKey()).append(":\t\t").append(StringUtils.join(item.getValue(), "/"))
                    .append("\r\n");
            }
            logger.info(msg.toString());
            return request;
        }
        //如果传递方式为RequestBody
        msg.append("\r\n\tRequestBody:");
        if (request.getContentLength() > 0) {
            request = new BodyReaderHttpServletRequestWrapper(request);
        }else {
            logger.info(msg.toString());
            return request;
        }
        BufferedReader br = request.getReader();
        String str ;
        StringBuilder retStr= new StringBuilder();
        while ((str = br.readLine()) != null) {
            retStr.append(str);
        }
        msg.append(retStr);
        logger.info(msg.toString());
        return request;
    }
    /**
     * 获取请求主机地址
     * @param request
     * @return
     */
    public String getRemoteHost(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return "0:0:0:0:0:0:0:1".equals(ip) ? "127.0.0.1" : ip;
    }
}