1 files changed, 53 insertions, 0 deletions
diff --git a/java/com/google/gerrit/httpd/CanonicalWebUrl.java b/java/com/google/gerrit/httpd/CanonicalWebUrl.java
new file mode 100644
index 0000000000..437ddf3e71
--- /dev/null
+++ b/java/com/google/gerrit/httpd/CanonicalWebUrl.java
@@ -0,0 +1,53 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// 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 com.google.gerrit.httpd;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.gerrit.common.Nullable;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import javax.servlet.http.HttpServletRequest;
+
+public class CanonicalWebUrl {
+  private final Provider<String> configured;
+
+  @Inject
+  CanonicalWebUrl(
+      @com.google.gerrit.server.config.CanonicalWebUrl @Nullable Provider<String> provider) {
+    configured = provider;
+  }
+
+  public String get(HttpServletRequest req) {
+    String url = configured.get();
+    return url != null ? url : computeFromRequest(req);
+  }
+
+  static String computeFromRequest(HttpServletRequest req) {
+    StringBuffer url = req.getRequestURL();
+    try {
+      url = new StringBuffer(URLDecoder.decode(url.toString(), UTF_8.name()));
+      url.setLength(url.length() - req.getServletPath().length());
+      if (url.charAt(url.length() - 1) != '/') {
+        url.append('/');
+      }
+      return url.toString();
+    } catch (UnsupportedEncodingException e) {
+      throw new IllegalStateException("Unsupported encoding for request URL " + url, e);
+    }
+  }
+}