Java URL encoding: URLEncoder vs. URI

Question

Looking on the W3 Schools URL encoding webpage, it says that @ should be encoded as %40, and that space should be encoded as %20.

I've tried both URLEncoder and URI, but neither does the above properly:

import java.net.URI; import java.net.URLEncoder;  public class Test {     public static void main(String[] args) throws Exception {          // Prints me%40home.com (CORRECT)         System.out.println(URLEncoder.encode("[email protected]", "UTF-8"));          // Prints Email+Address (WRONG: Should be Email%20Address)         System.out.println(URLEncoder.encode("Email Address", "UTF-8"));          // http://www.home.com/test?Email%[email protected]         // (WRONG: it has not encoded the @ in the email address)         URI uri = new URI("http", "www.home.com", "/test", "Email [email protected]", null);         System.out.println(uri.toString());     } } 

For some reason, URLEncoder does the email address correctly but not spaces, and URI does spaces currency but not email addresses.

How should I encode these 2 parameters to be consistent with what w3schools says is correct (or is w3schools wrong?)

Answer 1

Although I think the answer from @fge is the right one, as I was using a 3rd party webservice that relied on the encoding outlined in the W3Schools article, I followed the answer from Java equivalent to JavaScript's encodeURIComponent that produces identical output?

public static String encodeURIComponent(String s) {     String result;      try {         result = URLEncoder.encode(s, "UTF-8")                 .replaceAll("\\+", "%20")                 .replaceAll("\\%21", "!")                 .replaceAll("\\%27", "'")                 .replaceAll("\\%28", "(")                 .replaceAll("\\%29", ")")                 .replaceAll("\\%7E", "~");     } catch (UnsupportedEncodingException e) {         result = s;     }      return result; }