What's New in JDK 8 ?

1.Lamda Expressions I started with lambda expressions as this is probably the most sought after feature in the language after probably Generics/Annotations in Java 5. 2.Generic Type changes and improvements Taking clues from Lambdas, generic collections can also infer the data types to be used to an extent. The methods for instance using a generic collection need not specify genric types . Stream Collection Types (java.util.stream) A stream is a iterator that allows a single run over the collection it is called on. Along with Lambdas, this is another noteworthy feature to watch out for. You can use streams to perform functional operations like filer or map/reduce over collections which can be streamed as individual elements using Stream objects. Streams can run sequentially or parallely as desired. The parallel mode makes use of fork/join framework and can leverage power of multiple cores. 4. Functional Interfaces (java.util.function) These interfaces contain some default methods which need not be implemented and can run directly from the interface. This helps with existing code – changing interfaces need not make all the classes implementing it implement new methods. This is similar to Traits in Scala and functional interfaces will be compatible with lambdas. 5. Nashorn – The Node.js on JVM This is the javascript engine that enables us to run javascript to run on a jvm. It is similar to the V8 engine provided by chrome over which Node.js runs. It is compatible with Node.js applications while also allowing actual Java libraries to be called by the javascript code running on server. This is exciting to say at the least as it marries scalability and asynchronous nature of Node.js with safe and widespread server side Java middleware directly. 6.The Date/Time API is moved to java.time package and Joda time format is followed. Another goodie is that most classes are Threadsafe and immutable. 7.Type Annotations Now annotations can be used to decorate generic types itself. 8. Reflection api is slightly increased with the support of TypeName, GenericString, etc. String.join() method is a welcome addition as a lot of self created utility classes are created instead read less

Productivity In regards of productivity JDK 8 targets two main areas: - collections – a more facile way to interact with collections through literal extensions brought to the language - annotations – enhanced support for annotations, allowing writing them in contexts where are currently illegal (e.g. primitives) Performance The addition of the Fork/Join framework to JDK 7, was the first step that java took in the direction of multicore CPUs. JDK 8 takes this road even further by bringing closures’ support to java (lambda expression, that is). Probably the most affected part of java will be the Collections part, the closures combined with the newly added interfaces and functionalities pushing the java containers to the next level. Besides the more readable and shorter code to be written, by providing to the collections a lambda expression that will be executed internally the platform can take advantage of multicore processors. Modularity One of the most interresting pieces for the community was project jigsaw: “The goal of this Project is to design and implement a standard module system for the Java SE Platform, and to apply that system to the Platform itself and to the JDK.”. I am using past tense because, for the those of us that were hoping to get rid of the classpaths and classloaders, we have to postpone our excitement for Java 9, as for that point of time was also project jigsaw postponed. read less