IntelliJ IDEA way of editing multiple lines
I’ve seen this done in TextMate and I was wondering if there’s a way to do it in IDEA. Say I have the … Read more
Java
Difference between null and empty (“”) Java String
What is the difference between null and the “” (empty string)? I have written some simple code: String a = “”; String b … Read more
How to use MDC with thread pools?
In our software we extensively use MDC to track things like session IDs and user names for web requests. This works fine while … Read more
What’s the difference between session.persist() and session.save() in Hibernate?
Can anyone tell me what’s the advantage of persist() vs save() in Hibernate? 10 Answers 10
Difference between solr and lucene
I know that Lucene and Solr are 2 differents Apache projects that are made to work together, but I don’t understand what is … Read more
How to specify function types for void (not Void) methods in Java8?
I’m playing around with Java 8 to find out how functions as first class citizens. I have the following snippet: package test; import … Read more
How does Java Garbage Collection work with Circular References?
From my understanding, garbage collection in Java cleans up some objects if nothing else is ‘pointing’ to that object. My question is, what … Read more
How to encrypt String in Java
What I need is to encrypt string which will show up in 2D barcode(PDF-417) so when someone get an idea to scan it … Read more
How do I convert a byte array to Base64 in Java?
Okay, I know how to do it in C#. It’s as simple as: Convert.ToBase64String(byte[]) and Convert.FromBase64String(string) to get byte[] back. How can I … Read more
Difference between “on-heap” and “off-heap”
Ehcache talks about on-heap and off-heap memory. What is the difference? What JVM args are used to configure them? Best Answer 6
