Why is Java still changing?

Since the release of JDK 1.0 (Java 1.0) in 1996, Java has won a large following of students, project managers, and programmers who are active users. It’s an expressive language and continues to be used for projects both large and small. Its evolution (via the addition of new features) from Java 1.1 (1997) to Java 7 (2011) has been well managed. Java 8 was released in March 2014. So the question is this: why should you care about Java 8? We argue that the changes to Java 8 are in many ways more profound than any other changes to Java in its history. The good news is that the changes enable you to write programs more easily—instead of writing verbose code like the following (to sort a list of apples in inventory based on their weight),

Collections.sort(inventory, new Comparator<Apple>() {
 public int compare(Apple a1, Apple a2){
 return a1.getWeight().compareTo(a2.getWeight());
 }
});

in Java 8 you can write more concise code that reads a lot closer to the problem statement:

inventory.sort(comparing(Apple::getWeight));

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It reads “sort inventory comparing apple weight.” Don’t worry about this code for now. There’s also a hardware influence: commodity CPUs have become multicore—the processor in your laptop or desktop machine probably has four or more CPU cores within it. But the vast majority of existing Java programs use only one of these cores and leave the other three idle (or spend a small fraction of their processing power running part of the operating system or a virus checker).

Prior to Java 8, experts might tell you that you have to use threads to use these cores. The problem is that working with threads is difficult and error prone. Java has followed an evolutionary path of continually trying to make concurrency easier and less error prone. Java 1.0 had threads and locks and even a memory model—the best practice at the time—but these primitives proved too difficult to use reliably in nonspecialist project teams. Java 5 added industrial-strength building blocks like thread pools and concurrent collections. Java 7 added the fork/join framework, making parallelism more practical but still difficult. Java 8 has a new, simpler way of thinking about parallelism. But you still have to follow some rules, which you’ll learn in this book!

Source: Jaxenter