/*
* Copyright 2012 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.iri.impl;
import java.net.IDN;
/**
* IDNP: IDN Patched
*
* A wrapper around java.net.IDN to avoid a bug when checking result.
* It looks like the IDN is apply checks before fully converting, so this defers
* a similar check until the end.
*/
public class IDNP {
public static String toASCII(String host, int flags) {
if ((flags & IDN.USE_STD3_ASCII_RULES) != 0) {
return check(IDN.toASCII(host, flags ^ IDN.USE_STD3_ASCII_RULES));
} else {
return IDN.toASCII(host, flags);
}
}
// Step through each part of the host and ensure that they conform
private static String check(final String asciiHost) {
String[] parts = asciiHost.split("\\.");
for (String part: parts) checkPart(part);
return asciiHost;
}
// Part check: no leading or trailing hyphens, hyphens and alphanumerics.
// We try to follow java.net.IDN behaviour in our exceptions, in anticipation
// of dumping this class.
private static void checkPart(String part) {
if ( part.isEmpty() )
throw new IllegalArgumentException("Empty IDN part");
if (part.charAt(0) == '-' ||
part.charAt(part.length() - 1) == '-') {
throw new IllegalArgumentException("Has leading or trailing hyphen");
}
for (int i = 0; i < part.length(); i++) {
char c = part.charAt(i);
// Host is limited to hyphens and alpha numerics
if (c != '-' &&
!(c >= '0' && c <= '9') &&
!(c >= 'a' && c <= 'z') &&
!(c >= 'A' && c <= 'Z')) {
throw new IllegalArgumentException("Contains non-LDH characters");
}
}
}
}