Bye bye Groovy, you won't be missed :(

src/main/java/io/kamax/mxisd/spring/ConfigurationFailureAnalyzer.java

@@ -0,0 +1,38 @@
+/*
+ * mxisd - Matrix Identity Server Daemon
+ * Copyright (C) 2017 Maxime Dor
+ *
+ * https://max.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.spring;
+
+import io.kamax.mxisd.exception.ConfigurationException;
+import org.springframework.boot.diagnostics.AbstractFailureAnalyzer;
+import org.springframework.boot.diagnostics.FailureAnalysis;
+
+public class ConfigurationFailureAnalyzer extends AbstractFailureAnalyzer<ConfigurationException> {
+
+    @Override
+    protected FailureAnalysis analyze(Throwable rootFailure, ConfigurationException cause) {
+        String message = cause.getMessage();
+        if (cause.getDetailedMessage().isPresent()) {
+            message += " - " + cause.getDetailedMessage().get();
+        }
+        return new FailureAnalysis(message, "Double check the key value", cause);
+    }
+
+}