public static String findUrl(PsiFile file, int offset, String uri) {
final PsiElement currentElement = file.findElementAt(offset);
final XmlAttribute attribute = PsiTreeUtil.getParentOfType(currentElement, XmlAttribute.class);
if (attribute != null) {
final XmlTag tag = PsiTreeUtil.getParentOfType(currentElement, XmlTag.class);
if (tag != null) {
final String prefix = tag.getPrefixByNamespace(XmlUtil.XML_SCHEMA_INSTANCE_URI);
if (prefix != null) {
final String attrValue =
tag.getAttributeValue(XmlUtil.SCHEMA_LOCATION_ATT, XmlUtil.XML_SCHEMA_INSTANCE_URI);
if (attrValue != null) {
final StringTokenizer tokenizer = new StringTokenizer(attrValue);
while (tokenizer.hasMoreElements()) {
if (uri.equals(tokenizer.nextToken())) {
if (!tokenizer.hasMoreElements()) return uri;
final String url = tokenizer.nextToken();
return url.startsWith(HTTP_PROTOCOL) ? url : uri;
}
if (!tokenizer.hasMoreElements()) return uri;
tokenizer.nextToken(); // skip file location
}
}
}
}
}
return uri;
}
