Is there anything in particular that's available in Java that you couldn't get in Go or Python?
Is there anything in particular that's available in Java that you couldn't get in Go or Python?
Next step on the ladder is languages. You can mix any combination of Java, Scala, Groovy, Clojure, JRuby, Jython and others with little or no friction.
Then there's infrastructure. There's a good selection of rock solid application servers - Tomcat, Jetty and Glassfish comes to mind. The entire JDK toolchain, especially VisualVM, JConsole and JMX. Get a stacktrace or a heap dump from a running java process? Trivial and built in.
Finally, the libraries: JDBC is pretty neat: Every database under the sun plugs into the same interface. Terracotta has a pretty interesting line up (http://terracotta.org/products). Hadoop - it's a full ecosystem of it's own. Eclipse and IntelliJ IDEA. Apache POI for MS Office doc manipulation. Apache FOP is supposed to be pretty powerful. Lucene. Apache Commons.
A cross-platform UI toolkit that's pretty good all things considered? A reporting toolkit that produces PDFs according to custom templates?
(Swing and JasperReports, respectively)