JTK questions

• Convert Curl to Java equivalent
• Android mkdirs() not working
• How often should an Android app and server sync
• Order Springdoc operation parameters alphabetically
• java.sql.Timestamp to Joda Instant and vice versa
• Java 8 lambda adding to a list in a Hashmap, in a Hashmap
• Wildfly 10 Final indefinitely creating ActiveMQ-client-global-threads
• Interpolate function using Apache Commons Math
• Subtracting pointers

JTK answers