Why developers are so excited about Java 9

As the standard Java version is updated, developers can always get the desired functions from the upgraded version. So why is the release of Java 9 making developers so excited? Some main reasons are listed below:

1. Modular source code

The JDK source code will be organized in a modular form. The generation system will be enhanced in modular compilation, and the modules will be The boundaries between them will also be enforced. "Jigsaw's goal is to design and implement a standard modular system for the Java SE platform and apply the system to its own platform and JDK. Its main goal is to provide a simple scalable implementation for some small devices and improve Security and maintainability, improve application system performance, and provide developers with more development tools." This is described in the JDK optimization recommendations.

　2. Lightweight JSON API

　 This is an interface that uses the JSON data exchange format to generate documents and data streams. In some cases, JSON can completely replace XML. "JSON can be used in Web services, and Java SE will also adopt the JSON data format. This is also the most needed function provided in Java 9."

　　3. System process management

　This upgrade will The API for managing operating system processes has been improved and improved. The current API can only force developers to use local code, but this upgrade also overcomes this limitation. In Java SE 7, there are great restrictions on the operation of local operating system processes, but the new APIs in Java 9 also need to consider the differences between different operating systems, especially Windows. "The design of the API needs to adapt to mobile devices with different operating systems, and must be able to be deployed and applied on these devices. At the same time, the situation of multiple Java virtual machines in the same operating system should also be considered." This is how it is described in the JEP document .

　4. Improve competition locks

　This goal is to improve thread competition processing when accessing objects. The document says this: "Improving competition between locks is very beneficial to real-life application systems."

5. Segmented code cache

This mainly divides the code cache into several blocks, each block contains compiled code, which not only improves the performance of the program during runtime, but also makes it easier to expand.

　6. Smart Java Compiler

　This project is mainly to improve the performance of the Java compiler so that it can surpass JDK in compiling large projects. The current implementation is really great, not only improving the compilation speed, but also Incremental compilation capabilities. However, since the code quality and stability are not yet satisfactory, the project has not yet been released to the public, so stay tuned.