Support access tokens in headers (Fix #65) (#70)

src/main/java/io/kamax/mxisd/util/OptionalUtil.java

@@ -0,0 +1,33 @@
+/*
+ * mxisd - Matrix Identity Server Daemon
+ * Copyright (C) 2018 Kamax Sarl
+ *
+ * https://www.kamax.io/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package io.kamax.mxisd.util;
+
+import java.util.Optional;
+import java.util.function.Supplier;
+import java.util.stream.Stream;
+
+public class OptionalUtil {
+
+    public static <T> Optional<T> findFirst(Supplier<Optional<T>>... suppliers) {
+        return Stream.of(suppliers).map(Supplier::get).filter(Optional::isPresent).map(Optional::get).findFirst();
+    }
+
+}