&gt; Closure is just a piece of code you can pass and later execute. Some say we will have those in Java in 2128 with the release of Java 37.<p>Java 8 brought &quot;lambdas&quot;, which behave similarly to Groovy&#x27;s closures, though without the legacy inconsistencies. Have you read Jeremy Rayner&#x27;s account of how closures came to be in Groovy at <a href="http:&#x2F;&#x2F;www.javanicus.com&#x2F;blog2&#x2F;items&#x2F;191-index.html" rel="nofollow">http:&#x2F;&#x2F;www.javanicus.com&#x2F;blog2&#x2F;items&#x2F;191-index.html</a> ? I also did a writeup on that incident at <a href="http:&#x2F;&#x2F;groovy.codeplex.com&#x2F;wikipage?title=Blog02#15" rel="nofollow">http:&#x2F;&#x2F;groovy.codeplex.com&#x2F;wikipage?title=Blog02#15</a> .