【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()");
}
}
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;
} }
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);
}
}
}
▄︻┻┳═一tomcat与jetty接收请求参数的区别
▄︻┻┳═一比较两种方式的form请求提交
▄︻┻┳═一Post方式的Http流请求调用