Luke is a legacy application based on Java Struts. Struts is one of many Java web frameworks, designed to trigger HTTP requests actions– it is the routing of HTTP requests to a specific function call.
Now, on one screen, the user has filled the form and then the corresponding server-side action required to read the form data for eventId and act accordingly. In Struts it can be very simple:
int event_id = Integer.parseInt(request.getParameter("event_id"));
That’s the supposed way to do it. But if you don’t learn how to use a framework properly, you might end up writing something else:
public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception
int event_id = 0;
try
InputStream is = request.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String eventStr = "";
StringBuffer buff = new StringBuffer();
String line;
do
line = br.readLine();
buff.append(line);
while (br.readLine() != null);
eventStr = buff.toString();
StringTokenizer parseEventId = new StringTokenizer(eventStr, ",");
while (parseEventId.hasMoreTokens())
String eventString = parseEventId.nextToken();
if (eventString.startsWith("event_id"))
event_id = Integer.parseInt(eventString.substring(eventString.indexOf("=") + 1));
catch (Exception e)
e.printStackTrace();
...
This bunch of code chooses to read the entire body of the input stream as a string and then parse that string with the tokenizer, looking for a substring that starts with event_idat which point they can be divided into = and get an integer value.
This is all too complicated and it’s bad to reinvent the wheel, but the specific token we shared hints at deeper issues: ", "as well as the fact that ours read do/while the loop just reads each else line.
HTML form POST the request encodes the data either as application/x-www-form-urlencoded or multipart/form-data. None of these formats send commas to separate key/value pairs. Either the client side is applying its own custom formatting, which we need to parse, or this code is simply wrong.
But also, Struts has a complete set of model/form binding features, so the “official” way to do this would be to simply map to a Java Bean object.
Everything about this is wrong and over-engineered, and smells like it was written by someone who was “smarter” than everyone else, so couldn’t be bothered with a standard approach to anything.