Tell Spring Boot to use the simple HttpURLConnection for RestClient, …

…like in Spring boot 3.3

dspace-server-webapp/src/main/resources/application.properties

@@ -135,3 +135,15 @@ spring.servlet.multipart.max-file-size = 512MB
 
 # Maximum size of a multipart request (i.e. max total size of all files in one request) (default = 10MB)
 spring.servlet.multipart.max-request-size = 512MB
+
+##################################
+# Spring Boot's HTTP Client configuration (for RestClient and RestTemplate)
+# https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.4-Release-Notes#restclient-and-resttemplate
+#
+# "simple" tells Spring Boot to use JDK's HttpURLConnection (SimpleClientHttpRequestFactory)
+# We have to configure this explicitly for DSpace because Spring Boot's autoconfiguration will attempt to
+# use Jetty or similar if found on the classpath (and Jetty is on the classpath for Handle Server, etc)
+spring.http.client.factory = simple
+# "dont_follow" tells Spring Boot not to follow any redirects itself, but instead return the 3xx code to
+# the user's browser.
+spring.http.client.redirects = dont_follow