Wow, that's actually kinda tough to answer. There's been a LOT of changes in the Java world in the last 10 years - as you might guess. And I mean both in terms of the language itself, and the tooling and ecosystem as far as libraries and frameworks, etc.<p>The answer also depends a bit on what exactly you want to do. If you're mainly interested in web apps, it's one thing, "big data" is another world altogether, mobile (Android) has its own ecosystem, etc.<p>All of that said, here are some thoughts:<p>Generics and the newer Collections related stuff is one area that changed a lot. There's online documentation at:<p><a href="https://docs.oracle.com/javase/tutorial/java/generics/index.html" rel="nofollow">https://docs.oracle.com/javase/tutorial/java/generics/index....</a><p><a href="https://docs.oracle.com/javase/tutorial/java/generics/types.html" rel="nofollow">https://docs.oracle.com/javase/tutorial/java/generics/types....</a><p>and a decent, if somewhat older, book is <a href="http://shop.oreilly.com/product/9780596527754.do" rel="nofollow">http://shop.oreilly.com/product/9780596527754.do</a><p>Then there's the newer concurrency stuff that came along in the Java 5 / Java 6 era. Fork/Join, Executors, etc. <i>Java Concurrency In Practice</i> should still be useful to you, even though it is, again, a little bit dated now.<p><a href="https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz/dp/0321349601" rel="nofollow">https://www.amazon.com/Java-Concurrency-Practice-Brian-Goetz...</a><p>To get started with the Java 8 stuff, a book like "Java 8 in Action" would be good.<p><a href="https://www.amazon.com/Java-Action-Lambdas-functional-style-programming/dp/1617291994/ref=pd_lpo_sbs_14_t_1?_encoding=UTF8&psc=1&refRID=977J2A16G5NXN92BF98Y" rel="nofollow">https://www.amazon.com/Java-Action-Lambdas-functional-style-...</a><p>Another good intro the Java 8 era stuff is<p><a href="https://www.amazon.com/Beginning-Java-Language-Features-Expressions/dp/1430266589/ref=sr_1_1?s=books&ie=UTF8&qid=1506814235&sr=1-1&keywords=java+8+language+features" rel="nofollow">https://www.amazon.com/Beginning-Java-Language-Features-Expr...</a><p>And to make it even harder, Java 9 just dropped, so there's even more new stuff. I just picked up this book myself, but haven't had a lot of time to dig into it yet.<p><a href="https://www.amazon.com/Java-Programmers-4th-Deitel-Developer/dp/0134777565/ref=sr_1_3?s=books&ie=UTF8&qid=1506815511&sr=1-3&keywords=java+9" rel="nofollow">https://www.amazon.com/Java-Programmers-4th-Deitel-Developer...</a><p>For frameworks, Spring and Hibernate are both still popular and it wouldn't hurt to brush up on both of those. Spring Boot in particular has caught on for a lot of Java developers.<p><a href="https://www.amazon.com/Spring-Boot-Action-Craig-Walls/dp/1617292540/ref=pd_sim_14_4?_encoding=UTF8&psc=1&refRID=G9H7ATH8VD44YQ2017PM" rel="nofollow">https://www.amazon.com/Spring-Boot-Action-Craig-Walls/dp/161...</a><p>Also, Tomcat is still very popular for hosting java Web applications and services of various sorts. JBoss / Wildfly is still around, but JEE (as J2EE is now known) is not as popular as in the past (even though it has actually improved a LOT).<p>Play and Dropwizard are two more frameworks you might want to familiarize yourself with<p><a href="https://www.playframework.com/" rel="nofollow">https://www.playframework.com/</a><p><a href="http://www.dropwizard.io/1.1.4/docs/" rel="nofollow">http://www.dropwizard.io/1.1.4/docs/</a><p>In terms of tools, Eclipse is still popular, IntelliJ is probably the most popular Java IDE these days, and Netbeans seems to have faded from view a bit. Ant has fallen out of favour for builds, with most devs now using either Maven or Gradle. Read up on / play around with both of those and you'll be in good shape there.<p>Also, Java shops have also been affected by the overall move to "The Cloud" and you can't really ignore that either. If you haven't already, you'll probably want to familiarize yourself with AWS and the AWS SDK.<p>If you want to work/play in the "big data" space, you'll need some combination of Hadoop, Kafka, Spark, Hive, Storm, Flume, HBase, Impala, etc., etc., etc.