convert URLUtils to java since this contains hotspots

Author: lhotari

src/groovy/org/grails/plugin/resource/URLUtils.groovy

@@ -0,0 +1,96 @@
+package org.grails.plugin.resource;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URLDecoder;
+import java.util.regex.Pattern;
+
+/**
+ * @author Marc Palmer (marc@grailsrocks.com)
+ */
+class URLUtils {
+ 
+ public static Pattern externalURLPattern = Pattern.compile("^((https?:?)?//).*");
+ private static final int MAX_NORMALIZE_ITERATIONS = 3;
+
+ /**
+ * Take a base URI and a target URI and resolve target against the base
+ * using the normal rules e.g. "../x", "./x" "x" results in a link relative to the base's folder
+ * and / is app-absolute, and anything with a protocol // is absolute
+ *
+ * Please note, I take full responsibility for the nastiness of this code. I could not 
+ * find a nice way to do this, and I wanted to find an existing lib to do it. Its
+ * certainly not my finest moment. Sorry. Rely on the MenuTagTests.
+ *
+ * It's quite ugly in there.
+ */
+ public static String relativeURI(String base, String target) {
+ try {
+ return new URI(base).resolve(new URI(target)).normalize().toString();
+ }
+ catch (URISyntaxException e) {
+ throw new RuntimeException(e);
+ }
+ }
+ 
+ /**
+ * Works out if url is relative, such that it would need to be corrected if
+ * the file containing the url is moved
+ */
+ public static Boolean isRelativeURL(String url) {
+ return !url.startsWith("data:") &&
+ !url.startsWith("#") && 
+ !(url.indexOf("//") >= 0);
+ }
+
+ public static Boolean isExternalURL(String url){
+ if(url == null) return false;
+ return externalURLPattern.matcher(url).matches();
+ }
+ 
+ /**
+ * Normalizes and decodes uri once.
+ * Check if result contains \ , /../ , /./ or // after decoding and throws IllegalArgumentException in that case
+ * 
+ * @param uri
+ * @return
+ */
+ public static String normalizeUri(String uri) {
+ String current = uri;
+ int counter=0;
+ boolean changed = true;
+ // handle double-encoding
+ while (changed) {
+ if (counter++ > MAX_NORMALIZE_ITERATIONS) {
+ throw new IllegalArgumentException("unable to normalize input uri " + uri);
+ }
+ String normalized = doNormalizeUri(current);
+ changed = (!current.equals(normalized));
+ current = normalized;
+ }
+ return current;
+ }
+
+ private static String doNormalizeUri(String uri) {
+ if (uri == null) return null;
+
+ String normalized = RequestUtil.normalize(uri);
+ if (normalized == null) {
+ throw new IllegalArgumentException("illegal uri " + uri);
+ }
+
+ String decoded;
+ try {
+ decoded = URLDecoder.decode(normalized, "UTF-8");
+ }
+ catch (UnsupportedEncodingException e) {
+ throw new RuntimeException(e);
+ }
+ if(decoded.contains("\\") || decoded.contains("/./") || decoded.contains("/../") || decoded.contains("//")) {
+ throw new IllegalArgumentException("illegal uri " + uri);
+ }
+
+ return decoded;
+ }
+}