Oracle released Java SE 9 in September with over 150 new features. The latest version of the widely used programming language comes with several new features and APIs to accelerate application development for both large and small devices. At the same time, the features provided by Java 9 help programmers improve application performance, security, and maintainability. Hence, it becomes important for programmers to understand some of the key features provided by Java 9.
What programmers need to know about Java 9?
Java 9 dramatically improves the compilation process of your code through pre-compilation (AOT). Programmers can use AOT compilation to compile Java classes into native code even before the virtual machine launches them. AOT compilation improves the performance of both large and small applications by eliminating the major disadvantages of JIT compilation. Unlike JIT compilation, AOT compilation ensures that no Java method is left uncompiled.
Java 9 comes with a new command line tool real-eval-print-loop (REPL) – a wrapper. The wrapper is designed with functions for interactively evaluating declarative operators and expressions. The programmer can use Shell to evaluate the quality of Java code before compiling. He can simply enter a piece of code and collect feedback. Shell even has the ability to auto-complete tabs and add semicolons as required. The new REPL tool is forcing Java to compete with widely used programming languages such as Python and Scala.
Improved Stream API
When writing Java code, programmers use strings to express computations. Java 8 has made stream processing faster by providing the Streams API. Java 9 comes with an improved version of the Streams API that allows developers to take and remove elements from a Stream based on certain conditions by adding methods. In addition, the improved Streams API is designed with functions for creating a stream for nullable values and iterating over Streams.
Multi-Resolution Image API
Java 9 introduces a new interface – MultiResolutionImage – for creating a single image at multiple resolutions by encapsulating multiple images at different resolutions. Developers can optionally use the Java 9 Multi-Resolution Image API to get different variations of a single image. In addition, they can use the API to select a specific image based on the required resolution. Consequently, Java programmers can now use a single API to create a unified image at multiple resolutions and get variations of images at a specific resolution.
http: // 2 client API
Java 9 completely changed the way applications make HTTP calls. It replaces the HttpURLConnection API with a new HTTP client API. The HTTP client API supports both http: // 2 and WebSockets. However, the API is not currently part of Java SE. It is implemented as an incubator module that resides in the jdk.incubtor namespace. But the HTTP client API supports the latest communication standards, overcoming the disadvantages of the HttpURLConnection API.
When writing Java code, programmers explore ways to access and filter stack transfer efficiency. The latest version of Java simplifies stack traversal by providing the stack traversal API. The new API makes it easier for programmers to access and filter stack trace information. In addition, it supports both short and long walks. Consequently, it becomes easier for programmers to access and filter the entire stack without relying on the virtual machine to collect stack information.
Datagram Transport Layer Security (DTLS) API
Java 9 helps developers build secure applications by providing APIs for Datagram Transport Layer Security (DTLS). The API ensures the security of communication between the client and the server against the possibility of data tampering, message tampering and interception. In addition, it provides communication confidentiality for a variety of Datagram Protocol (DTP) applications. Although DTLS is designed around Transport Layer Security (TLS), it implements SSL.
Improved process API
Often Java programmers find it difficult to control and manage operating system processes. A process API provided by earlier developers for accessing native code and writing additional code. But the improved Process API provided by Java 9 makes it easier for programmers to monitor and control operating system processes. They can use the API to make the Java application interact directly with the operating system. In addition, they can take advantage of new methods for handling process names and states without writing additional code.
Despite the provision of several new features, Java 9 does not support some of the features provided by Java 8. For example, it no longer supports the Applet API. Java web developers must switch from the Applet API to Java Web Start in order to launch applications from web browsers. Likewise, Java 8 accelerates the development of garbage collectors in the HotSpot VM by excluding the Concurrent Mark Sweep (CMS) garbage collectors. With the most recent version of Java, programmers also have no way of getting Java import warnings and choosing a JRE at startup.
Overall, Java 9 contains several new features to make it easier to develop applications for both large and small devices. However, some binaries and source code introduced in Java 9 are incompatible with earlier versions of the programming language. Programmers even have to make a few code changes and update libraries when porting their existing applications to Java 9. But developers should consider upgrading their existing applications to Java 9 to take advantage of these new features and improvements. Java developers should also use these highly recommended tools for better programming.