The difference between HTTP Content_Type Multipart/form-data and application/x-www-form-urlencoded

Recently in the making of an app, the server needs to log, record all the requested URL, IP and parameters, say the parameters, then the problem, I use filters to record the log, to see how I write in the filter:

public void DoFilter (ServletRequest arg0, Servletresponse arg1,filterchain arg2) throws IOException, Servletexception { HttpServletRequest request = (httpservletrequest) arg0;    Get urlstring URL = Request.getrequesturl (). toString ();//Get parameter/*stringbuffer info=new java.lang.StringBuffer ();    InputStream In=request.getinputstream ();    Bufferedinputstream buf=new Bufferedinputstream (in);    Bufferedinputstream Bufbak=buf;     Byte[] Buffer=new byte[1024];    int iread;    while ((Iread=buf.read (buffer))!=-1) {info.append (new String (Buffer,0,iread, "UTF-8"));     } logger.info (info.tostring () + "------xxxxx------"); *//* collection<part> ps= request.getparts ();     For (part P:ps) {collection<string> cs=p.getheadernames ();     for (String S:cs) {logger.info ("------Collection----" +s); }}*/string Name=request.getparameter ("UserId"); Logger.info ("--------name------------" +name); map<string,string[]> map = Request.getparametermap (); String queryString = "";              For (String Key:map.keySet ()) {string[] values = Map.get (key);                  for (int i = 0; i < values.length; i++) {String value = Values[i];              QueryString + = key + "=" + Value + "&"; }} logger.info ("--------------------" +querystring); String userid=null;//get user ID string[] userids = (string[]) map.get ("UserId"); if (null!=userids&&0<userids.length) {userid=userids[0];} Active area ipstring IP = this.getclientip (Request), Logger.info (URL + "" + Gson.tojson (map) + "+ IP +" "+userid);//logger.i NFO (Arg0.hashcode () + "-------hashcode-------------" +req.hashcode ()); Arg2.dofilter (arg0, arg1);}

But after running to find Request.getparametermap () get no data, what is the matter?

Later, I looked for andriod client open staff to look at their client's request code, found that they are using httpurlconnection to make the request, the approximate code is as follows:

URL url = new URL (u); HttpURLConnection urlconn = (httpurlconnection) url.openconnection ();//Set whether to httpurlconnection output, because this is a POST request, parameters to be placed in/ /HTTP body, so it needs to be set to True, False;urlconn.setdooutput (true) by default;//Whether the setting is read from HttpURLConnection and true by default; Urlconn.setdoinput (TRUE);//Post request cannot use cache Urlconn.setusecaches (FALSE);//Set the content type to be a serializable Java object//(if this item is not set, when the serialized object is transferred, When the Web service default is not this type may throw java.io.EOFException) Urlconn.setrequestproperty ("Content-type", "multipart/form-data;        boundary= "+" 00content0boundary00\r\n "); Application/x-java-serialized-object//urlconn.setrequestproperty ("Content-type", "application/ X-www-form-urlencoded ");//The method for setting the request is" POST ", the default is Geturlconn.setrequestmethod (" post ");//Connection,    All of the above configuration for urlconn must be done before connect, urlconn.connect ();/* * Post parameter method */outputstream OS = Urlconn.getoutputstream (); string param = new string (p);//parameter comma-delimited string eg.name=xiaoming,age=23,sex=0 os.write (Param.getbytes ());//    Call the getInputStream () function of the HttpURLConnection connection object,//Send the complete HTTP request message encapsulated in the memory buffer to the server. StringBuffer info=nEW Java.lang.StringBuffer (); InputStream instrm = Urlconn.getinputstream ();    <=== Note that the code snippet that actually sends the request is here Bufferedinputstream buf=new Bufferedinputstream (INSTRM);     Byte[] Buffer=new byte[1024];    int iread;    while ((Iread=buf.read (buffer))!=-1) {info.append (new String (Buffer,0,iread, "UTF-8"));    } System.out.println (info.tostring () + "------xxxxx------"); return info.tostring ();

The client's request Content-type is set to the

Multipart/form-data; boundary= "+" 00content0boundary00\r\n "

This is a format for media MIME , which is typically used to transfer large text or binary file uploads. Therefore, in the Request.getparametermap () can not get the parameters of the client request

If the Content-type is set to

application/x-www-form-urlencoded

parameters can be obtained through REQUEST.GETPARAMETERMAP (), but this encoding is inefficient when sending large amounts of text to the server, including text or binary data that contains non-ASCII characters

The difference between HTTP Content_Type Multipart/form-data and application/x-www-form-urlencoded