A DESCRIPTION OF THE REQUEST :
Currently URLDecoder has this API:

static String decode(String s, String enc) throws UnsupportedEncodingException

Which is unsafe and annoying because of checked Exception which is in most cases useless when used with a fixed String in code.

Instead, URLDecoder should (additionally) have a method
static String decode(String s, Charset charset)
which does not raise a checked Exception. 



JUSTIFICATION :
This is in line with

public byte[] getBytes(Charset charset) 
public byte[] getBytes(String charsetName)
            throws UnsupportedEncodingException

of java.lang.String

The equivalent reasoning holds for URLEncoder.encode()

As a result code written using these classes can be safer against typos ("UFT-8"), and unnecessary try/catch blocks can be eliminated.