The sort answer is that this data is hidden in the request InputStream.
The following servlet is a demo of how you can use this (I am running it on a JBoss 7.1.1):
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(name="fooServlet", urlPatterns="/foo")
public class FooServlet extends HttpServlet
{
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
InputStream is = req.getInputStream();
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buf = new byte[32];
int r=0;
while( r >= 0 ) {
r = is.read(buf);
if( r >= 0 ) os.write(buf, 0, r);
}
String s = new String(os.toByteArray(), "UTF-8");
String decoded = URLDecoder.decode(s, "UTF-8");
System.err.println(">>>>>>>>>>>>> DECODED: " + decoded);
System.err.println("================================");
Enumeration<String> e = req.getParameterNames();
while( e.hasMoreElements() ) {
String ss = (String) e.nextElement();
System.err.println(" >>>>>>>>> " + ss);
}
System.err.println("================================");
Map<String,String> map = makeQueryMap(s);
System.err.println(map);
//////////////////////////////////////////////////////////////////
//// HERE YOU CAN DO map.get("id") AND THE SENT VALUE WILL BE ////
//// RETURNED AS EXPECTED WITH request.getParameter("id") ////
//////////////////////////////////////////////////////////////////
System.err.println("================================");
resp.setContentType("application/json; charset=UTF-8");
resp.getWriter().println("{'result':true}");
}
// Based on code from: http://www.coderanch.com/t/383310/java/java/parse-url-query-string-parameter
private static Map<String, String> makeQueryMap(String query) throws UnsupportedEncodingException {
String[] params = query.split("&");
Map<String, String> map = new HashMap<String, String>();
for( String param : params ) {
String[] split = param.split("=");
map.put(URLDecoder.decode(split[0], "UTF-8"), URLDecoder.decode(split[1], "UTF-8"));
}
return map;
}
}
With the request:
$.post("foo",{id:5,name:"Nikos",address:{city:"Athens"}})
The output is:
>>>>>>>>>>>>> DECODED: id=5&name=Nikos&address[city]=Athens
================================
================================
{address[city]=Athens, id=5, name=Nikos}
================================
(NOTE: req.getParameterNames() does not work. The map printed in the 4th line contains all the data normally accessible using request.getParameter(). Note also the nested object notation, {address:{city:"Athens"}} → address[city]=Athens)
Slightly unrelated to your question, but for the sake of completeness:
If you want to use a server-side JSON parser, you should use JSON.stringify for the data:
$.post("foo",JSON.stringify({id:5,name:"Nikos",address:{city:"Athens"}}))
In my opinion the best way to communicate JSON with the server is using JAX-RS (or the Spring equivalent). It is dead simple on modern servers and solves these problems.
