tomcat与jetty接收请求参数的区别

【场景】

服务端点对点通知。
A服务发起请求B服务，B同步返回接收成功；然后B开始处理逻辑；B处理完成后异步通知给A；A接收请求并处理，同步回写响应给B；完成。

【先上代码】

服务端（接收端）代码：

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Map;

public class ServController extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("===============================");
        

        try {
            Map<String, String[]> mapByRequest = request.getParameterMap();
//            Map mapByRequest = ReadHttpRequest.getRequestMap(request); //request.getParameterMap();
            System.out.println("map count:" + mapByRequest.size());

            if(mapByRequest!=null && mapByRequest.size()>0) {
                System.out.println("map[0]:" + mapByRequest.keySet().toArray()[0]);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        
//        String requestString = ReadHttpRequest.getRequestInputStream(request);
//        System.out.println("requestString:" + requestString);

        HtmlUtil.write(response, "success");
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        HtmlUtil.write(response, "this is doGet()");
    }
}

View Code

客户端（请求端）HttpUtil工具类：

import javax.net.ssl.HttpsURLConnection;
import java.io.*;
import java.net.HttpURLConnection;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.util.Map;

public class HttpUtil {

    /**
     * 发送http请求并接收返回,字符集默认UTF-8
     *
     * @param url         请求地址
     * @param sendData    发送数据
     * @param connTimeOut 连接超时
     * @param readTimeOut 响应超时
     * @return 返回报文
     * @throws Exception
     */
    public static String sendAndRcvHttpPost(String url, String sendData, int connTimeOut, int readTimeOut) {
        return sendAndRcvHttpPost(url, sendData, "UTF-8", connTimeOut, readTimeOut, "");
    }

    /**
     * 发送http请求并接收返回，（指定字符集）
     *
     * @param url         请求地址
     * @param sendData    发送数据
     * @param charset   字符集
     * @param connTimeOut 连接超时
     * @param readTimeOut 响应超时
     * @param lineSpliter 换行符
     * @return 返回报文
     * @throws Exception
     */
    public static String sendAndRcvHttpPost(String url, String sendData, String charset, int connTimeOut, int readTimeOut, String lineSpliter) {
        return sendAndRcvHttpPostBase(url, sendData, charset, connTimeOut, readTimeOut,
                "application/x-www-form-urlencoded;charset=" + charset,
//                "text/plain",
                null, lineSpliter);
    }

    public static String sendAndRcvHttpPostBase(String url, String oriData, String charset, int connTimeOut, int readTimeOut,
                                                String contentType, Map<String, String> header, String lineSpliter) {
        Long curTime = System.currentTimeMillis();
        String tag = "@" + curTime;
        String result = "";
        BufferedReader in = null;
        DataOutputStream out = null;
        int code = 999;
        HttpsURLConnection httpsConn = null;
        HttpURLConnection httpConn = null;
        InputStream httpin = null;
        try {
            byte[] sendData = oriData.getBytes(charset);
            tag = sendData.hashCode() + tag;
//            Trace.logInfo(Trace.COMPONENT_HTTP, "SimpleHttpConnUtil Prepare:"+tag );
            URL myURL = new URL(url);
//            Trace.logInfo(Trace.COMPONENT_HTTP, "请求地址："+url);

            httpConn = (HttpURLConnection) myURL.openConnection();
            httpConn.setRequestProperty("Accept-Charset", charset);
            httpConn.setRequestProperty("user-agent", "Rich Powered/1.0");
            if (header != null) {
                for (String key : header.keySet()) {
                    httpConn.setRequestProperty(key, (String) header.get(key));
                }
            }
            httpConn.setRequestMethod("POST");
            httpConn.setUseCaches(false);
            httpConn.setRequestProperty("Content-Type", contentType);
            httpConn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;");
//                httpConn.setRequestProperty("Accept-Encoding","gzip, deflate, sdch");
            httpConn.setRequestProperty("Accept-Language", "zh-CN,zh;");
            httpConn.setRequestProperty("Cache-Control", "no-cache");
            httpConn.setRequestProperty("Pragma", "no-cache");
            httpConn.setRequestProperty("Content-Length", sendData.length + "");
            httpConn.setConnectTimeout(connTimeOut);
            httpConn.setReadTimeout(readTimeOut);
            httpConn.setDoInput(true);
            httpConn.setInstanceFollowRedirects(true);
            if (sendData != null) {
                httpConn.setDoOutput(true);
                // 获取URLConnection对象对应的输出流
                try {
                    httpConn.connect();
                } catch (Exception e) {
                    e.printStackTrace();
                    return null;
                }
                out = new DataOutputStream(httpConn.getOutputStream());
                // 发送请求参数
                out.write(sendData);
                // flush输出流的缓冲
                out.flush();
                out.close();
            }
            // 取得该连接的输入流，以读取响应内容
            code = httpConn.getResponseCode();
            httpin = httpConn.getInputStream();

            if (HttpURLConnection.HTTP_OK == code) {
                String line;

                in = new BufferedReader(new InputStreamReader(httpin, charset));
                while ((line = in.readLine()) != null) {
                    result += line + lineSpliter;
                }
            } else {
                result = null;
                throw new Exception("支付失败,服务端响应码：" + code);
            }
        } catch (SocketTimeoutException e) {
//            Trace.logError(Trace.COMPONENT_ACTION, "获取返回报文超时!",e);
            result = "TO";
        } catch (Exception e) {
//            Trace.logError(Trace.COMPONENT_ACTION, "http通讯失败 !",e);
            result = null;
        } finally {
//            Trace.logInfo(Trace.COMPONENT_ACTION,"对方地址："+url);
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                }
            }
            if (httpConn != null) {
                httpConn.disconnect();
            }
            if (httpsConn != null) {
                httpsConn.disconnect();
            }
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                }
            }
        }
//        Trace.logInfo(Trace.COMPONENT_HTTP, "SimpleHttpConnUtil "+tag+" end for "+(System.currentTimeMillis()-curTime)+"ms");
        return result;
    }

}

View Code

客户端测试方法：

public class TestMain {
    public static void main(String[] args) {
//        String reqData ="p1=a&p2=b&p3=c";
        String reqData = "{\"interfaceName\":\"RegisterNotify\",\"merSignMsg\":\"APrWHHydX41atXjfadKBfDPUhKBQbZ6fTKcnHGtVBhe9qpSfArVqRFrlf2wgw9gzmMnGo3x15XKXAZnC51WU60FXNVj2kaxpWYzpuh6rvUDrDVQV6Z7SHEI8GvrMLE8uOG2TPR0Xu6v71o8u8TJsWsiVOP/ncsAHSzSz%%2B2Ch7N3E5ePCQi84To7LvSO5HrtUUmTbc%2BrmG2frJfYJNfvsxuGvt9U2MqmFeWFE98fK5e5SFUSSZLtqj42N18ppSZWSxN3MleGDTsy75zR3JxO6ol99lCPea4zqLmnUoEFlnJ3J6vXXUVXnMuSX5Mw%3D%3D\",\"merchantId\":\"M100002734\",\"tranData\":\"PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iR0JLIiA%2FPjxCMkNSZXM%2BPHN0YXR1cz4wPC9zdGF0dXM%2BPGJpbmRTdHM%2BMTwvYmluZFN0cz48Y3VzdG9tZXJJZD5DMTAwMDE0Mjc1PC9jdXN0b21lcklkPjxjb21wYW55PtDs1t3TzrHpzOzPwsLD087Qxc%2Bi18nRr9PQz965q8u%2BPC9jb21wYW55PjxyZWZ1c2VSZWFzb24vPjwvQjJDUmVzPg%3D%3D\",\"version\":\"B2C1.0\"}";
        String reqUrl = "http://localhost:8080/test_tomcat_web_war_exploded/form03_6_2_Token_OpenCard_Back";
//        String reqUrl="http://localhost:8083/H5api/xx";
        String result = HttpUtil.sendAndRcvHttpPost(reqUrl, reqData, 100000, 1000000);
        System.out.println(result);
    }
}

【测试结论】

Tomcat和jetty对于HttpServletRequest.getParameterMap()的处理不同。jetty可以直接获取到请求参数；而Tomcat获取不到。下面是Tomcat的日志：

六月 11, 2019 10:11:53 上午 org.apache.tomcat.util.http.Parameters processParameters
信息: Character decoding failed. Parameter [{"interfaceName":"RegisterNotify","merSignMsg":"APrWHHydX41atXjfadKBfDPUhKBQbZ6fTKcnHGtVBhe9qpSfArVqRFrlf2wgw9gzmMnGo3x15XKXAZnC51WU60FXNVj2kaxpWYzpuh6rvUDrDVQV6Z7SHEI8GvrMLE8uOG2TPR0Xu6v71o8u8TJsWsiVOP/ncsAHSzSz%%2B2Ch7N3E5ePCQi84To7LvSO5HrtUUmTbc%2BrmG2frJfYJNfvsxuGvt9U2MqmFeWFE98fK5e5SFUSSZLtqj42N18ppSZWSxN3MleGDTsy75zR3JxO6ol99lCPea4zqLmnUoEFlnJ3J6vXXUVXnMuSX5Mw%3D%3D","merchantId":"M100002734","tranData":"PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iR0JLIiA%2FPjxCMkNSZXM%2BPHN0YXR1cz4wPC9zdGF0dXM%2BPGJpbmRTdHM%2BMTwvYmluZFN0cz48Y3VzdG9tZXJJZD5DMTAwMDE0Mjc1PC9jdXN0b21lcklkPjxjb21wYW55PtDs1t3TzrHpzOzPwsLD087Qxc%2Bi18nRr9PQz965q8u%2BPC9jb21wYW55PjxyZWZ1c2VSZWFzb24vPjwvQjJDUmVzPg%3D%3D","version":"B2C1.0"}] with value [] has been ignored. Note that the name and value quoted here may be corrupted due to the failed decoding. Use debug level logging to see the original, non-corrupted values.
Note: further occurrences of Parameter errors will be logged at DEBUG level.

map count:0

Character decoding failed.Parameter [dd] with value [] has been ignored. 百度翻译为：字符解码失败。已忽略值为[]的参数[dd]。

我的Tomcat版本是7.0.93;jetty版本是6.1.26。通过比较两者的servlet-api.jar，发现Tomcat7的servlet-api的版本是3.0，而jetty的servlet-api的版本是2.5。或许是这种版本的差异导致结果不同。试图跟踪源码来一识庐山真面目，jetty的进去了，但从RequestWapper类里也看不到什么；Tomcat的则进不去。

进一步通过Tomcat测试发现：对于请求参数里的merSignMsg，当我改变其值（去掉开头的一些字符）时，Tomcat就能获取到了。看来还是Tomcat处理字符编码的问题。

【话说回来】

话说回来，上面案例content-type用form实在不合适不地道，因为想获取到请求数据，得取key的值而不是value，这不符合常用的套路啊，由此我的同事那天在接收数据时很折腾了一番。像这种上送json字符串的，改用text/plain更合适，这样的话，接收端通过读取HttpServletRequest的输入流就可以获取到请求数据。

附上读取HttpServletRequest流的代码：

package com;

import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class ReadHttpRequest {

    /**
     * 从request.ParameterMap获取数据---适用于表单请求
     * @param request
     * @return
     * @throws UnsupportedEncodingException
     * @throws Exception
     */
    public static Map getRequestMap(HttpServletRequest request) throws UnsupportedEncodingException,Exception {
        Map result = new HashMap();
        Map<String, String[]> map = request.getParameterMap();
        if (0 == map.size()) {
            System.out.println("未获取到任何请求参数.");
//            throw new  Exception("未获取到任何请求参数.");
            return result;
        }

        for (Iterator iter = map.entrySet().iterator(); iter.hasNext(); ) {
            Map.Entry element = (Map.Entry) iter.next();
            Object strKey = element.getKey();  //key值
            String[] value = (String[]) element.getValue(); //value,数组形式
            String values = "";
            for (int i = 0; i < value.length; i++) {
                values += "," + value[i];
            }
            result.put(strKey.toString(), values.replaceFirst(",", ""));
        }
        return result;
    }


    /**
     * 从输入流获取数据---适用于流请求
     * @param request
     * @return
     */
    public static String getRequestInputStream(HttpServletRequest request) {
        InputStream in = null;
        ByteArrayOutputStream out = null;
        try {
            in = request.getInputStream();
            out = new ByteArrayOutputStream();
            in2OutStream(in, out, 1024 * 1024);
            return out.toString("UTF-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if (in != null) in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
    private static void in2OutStream(InputStream in, OutputStream out,
                                     int bufferSize) throws IOException {
        byte[] buffer = new byte[bufferSize];// 缓冲区
        for (int bytesRead = 0; (bytesRead = in.read(buffer)) != -1; ) {
            out.write(buffer, 0, bytesRead);
            Arrays.fill(buffer, (byte) 0);
        }
    }
}