Junit5 (latest two commits) (#825)

* PDF to X

* PDF to X

* Remove created doc

* Code fixes and cleanup for PDF module

* Fix web.xml in spring-mvc-web-vs-initializer project

* Rollback web.xml

* Fixes to PDF article

* Merge with main eugen branch

* Junit 5

* Fix name of test and modifier

junit5/src/test/java/com/baeldung/StringUtils.java

@@ -0,0 +1,11 @@
+package com.baeldung;
+
+public final class StringUtils {
+
+	public static Double convertToDouble(String str) {
+		if (str == null) {
+			return null;
+		}
+		return Double.valueOf(str);
+	}
+}