openid/src/main/java/org/springframework/security/openid/OpenIDAuthenticationFilter.java
private String utf8UrlEncode(String value) {
		try {
			return URLEncoder.encode(value, "UTF-8");
		}
		catch (UnsupportedEncodingException e) {
			Error err = new AssertionError(
					"The Java platform guarantees UTF-8 support, but it seemingly is not present.");
			err.initCause(e);
			throw err;
		}
	}
private String utf8UrlEncode(String value) {
		try {
			return URLEncoder.encode(value, "UTF-8");
		}
		catch (UnsupportedEncodingException e) {
			Error err = new AssertionError(
					"The Java platform guarantees UTF-8 support, but it seemingly is not present.");
			err.initCause(e);
			throw err;
		}
	}
Performs URL encoding with UTF-8

@param value the value to URL encode
@return the encoded value