Java - Deprecated

Last Updated: 2022-04-25

Java has a huge ecosystem, but not everything is worth learning. Here's a growing list of noises that you could safely ignore, or things you should mindfully avoid.

Some of these are clearly labeled as "Deprecated", or even removed from JDK after a certain release; some are still widely used but we have good reasons not to.

Deprecated Modules/Packages/Functions

• Java Applet: deprecated since Java 9 and removed from Java 11.
• JSP: an ancient way to build web pages.
• Nashorn: that JavaScript engine, deprecated since Java 11. Reason: it's hard to keep up with the pace of the fast evolving JavaScript/ECMAScript.
• JavaFX: spinoff from JDK since Java 11.
• java.lang.Object.finalize() is deprecated since Java 9

Java EE and Corba packages removed from Java SE

Removed in Java 11 from SE, as part of JEP 320.

• java.xml.ws (JAX-WS, plus the related technologies SAAJ and Web Services Metadata)
• java.xml.bind (JAXB)
• java.activation (JAF)
• java.xml.ws.annotation (Common Annotations)
• java.corba (CORBA)
• java.transaction (JTA)
• java.se.ee (Aggregator module for the six modules above)
• jdk.xml.ws (Tools for JAX-WS)
• jdk.xml.bind (Tools for JAXB)

To check out the current JDK modules(after Java 9):

$ java --list-modules

Classes Not Deprecated But Have Better Alternatives

• Date and Calendar class should be avoided after the new java.time package in Java 8.
• prefer Executor over working directly on Thread
• SortedSet and SortedMap replaced by NavigableSet and NavigableMap in Java 6.
• avoid Vector, use ArrayList
• avoid Stack, use ArrayDeque
• avoid Hashtable and Dictionary, use LinkedHashMap
• Enumeration => Iterator

Others

• prefer composition to inheritance
• PermGen is replaced by Metaspace