I am trying to figure out how to pass multiple parameters in a URL. I want to pass latitude and longitude from my android class to a java servlet. How can I do that?
URL url;
double lat=touchedPoint.getLatitudeE6() / 1E6;
double lon=touchedPoint.getLongitudeE6() / 1E6;
url = new URL(""+lat+lon);
In this case output (written to file) is 28.53438677.472097.
This is working but I want to pass latitude and longitude in two separate parameters so that my work at server side is reduced. If it is not possible how can I at least add a space between lat & lon so that I can use tokenizer class to get my latitude and longitude. I tried following line but to no avail.
url = new URL(""+lat+" "+lon);
output- Nothing is written to file
url = new URL(""+lat+"&?param2="+lon);
output- 28.534386 (Only Latitude)
url = new URL(""+lat+"?param2="+lon);
output- 28.532577?param2=77.502996
My servlet code is as follows:
req.setCharacterEncoding("UTF-8");
resp.setCharacterEncoding("UTF-8");
final String par1 = req.getParameter("param1");
final String par2 = req.getParameter("param2");
FileWriter fstream = new FileWriter("C:\\Users\\Hitchhiker\\Desktop\\out2.txt");
BufferedWriter out = new BufferedWriter(fstream);
out.write(par1);
out.append(par2);
out.close();
Also I wanted to the know is this the most safe and secured way to pass the data from android device to server.
3 Answers
This
url = new URL(""+lat+"¶m2="+lon);
must work. For whatever strange reason1, you need ? before the first parameter and & before the following ones.
Using a compound parameter like
url = new URL(""+lat+"_"+lon);
would work, too, but is surely not nice. You can't use a space there as it's prohibited in an URL, but you could encode it as %20 or + (but this is even worse style).
1 Stating that ? separates the path and the parameters and that & separates parameters from each other does not explain anything about the reason. Some RFC says "use ? there and & there", but I can't see why they didn't choose the same character.
I do not know much about Java but URL query arguments should be separated by "&", not "?"
is good place for reference using "sub-delim" as keyword. is another good source.
You can pass multiple parameters as "?param1=value1¶m2=value2"
But it's not secure. It's vulnerable to Cross Site Scripting (XSS) Attack.
Your parameter can be simply replaced with a script.
Have a look at this article and article
You can make it secure by using API of StringEscapeUtils
static String escapeHtml(String str)
Escapes the characters in a String using HTML entities.
Even using https url for security without above precautions is not a good practice.
Have a look at related SE question:
