First chapter: Java

Disclaimer: Java System in-depth learning resources and documentation are all from Oracle officialWhy use Java?

Java is the foundation of almost any Web application and a global standard for developing and delivering mobile apps, games, web-based content, and enterprise software. With more than 9 million developers worldwide, Java can help you efficiently develop and deploy exciting applications and services. With its complete tools, mature ecosystems, and robust performance, Java can even provide application portability across the most distributed computing environments. Until now, Java is divided into several parts:

Java Platform Enterprise Edition (Java EE)

The Java Platform Enterprise Edition (Java EE) is the industry standard for Enterprise Java computing. Java EE 7 leverages new features to enhance HTML5 support, increase developer productivity, and better meet enterprise requirements, and developers can better support the latest Web applications and frameworks with less boilerplate code, while gaining greater scalability and richer, cleaner functionality.

Java Platform Standard Edition (Java SE)

Java SE is designed to help you develop secure, portable, high-performance applications for the widest range of computing platforms. By developing applications that can be used in heterogeneous environments, organizations can significantly increase end-user productivity, improve communication and collaboration, and significantly reduce the cost of ownership of enterprise management software and consumer applications.

Java Embedded (embedded)

If you want more choices, more protection, and more powerful features, Java will be the perfect choice for you. Oracle provides a wide range of solutions from servers to embedded devices for resource-constrained devices and desktop-class systems. These solutions provide high-performance real-time capabilities that enable you to protect your data while securely accessing resources, so you can make your devices more effective.

Java (Java ME) for mobile devices

The world has a large number of Java mobile phone developers, operators and OEMs using the Java Platform Micro version (Java ME) to develop feature telephony products. Oracle is a leader in the field of mobile telephony technology, which has been applied to 3 billion of devices and the number of devices continues to increase.

Oracle Java Cloud Services

Oracle Java Cloud Services provides an enterprise-class platform for developing and deploying applications in the cloud. With Oracle WebLogic Server, it provides instant access to cloud environments that support any standard Java EE application, as well as integrated security and database access to help you achieve the highest productivity.

Features and benefits

features	Advantages
Platform Independence	Java can run on most major hardware and operating system platforms. Can be run directly from Oracle's JVM software through one of the many partners in the Java ecosystem, or as part of the OPENJDK community.
Performance	Hotspots and JRockit are examples of virtual machine technologies that have become obvious, making Java one of the fastest programming environments. Built-in optimizations for multithreaded environments enable Java to be faster.
Easy to learn	Java is the preferred programming language for many universities and educational institutions around the world. Java's model for memory management, multithreading, and exception handling makes it a powerful language for both new and developed developers.
Based on standards	The Java language and its related technologies continue to develop-JCP functions through the Java Standards Development Organization (JCP), which is the technical specification for developing Java technology.
Global prevalence	Java is the world's most popular application platform, and has created a vibrant developer ecosystem that includes powerful tools, rich books, libraries, code examples, and more.
Unified Run-time environment	Java allows you to deploy with confidence in a variety of runtime environments that cover Java SE on the desktop, Java SE for embedded devices, and Oracle Java ME Embedded Client.
Optimized for embedded devices	Java SE for embedded devices addresses key requirements such as support for embedded processors, power management, less resource-intensive deployments, and more. The Oracle Java ME Embedded Client is based on a connection device configuration (CDC, a subset of the Java SE platform) that provides Java performance for resource-constrained devices.
High-performance, portable applications	Java enables native performance while also providing portability between a variety of embedded processors and operating systems.
A proven security model	Java provides a highly secure, advanced application environment that is ideal for Web-based applications.
Java Platform Enterprise Edition (Java EE) 6	Java EE 6 uses a new lightweight web profile to create next-generation Web applications, giving full play to the full functionality of the Java EE 6 Platform for enterprise applications. Developers can benefit from more annotations, more pojo, simplified encapsulation, and fewer XML configurations.

These are all Java technology directions. To learn a technology, the first to learn to implement the language of this technology, let us learn the Java language, starting from Java SE: The current Java language version is mainly divided into Java se 5 java se 6 java se 7 Java se 8, such as 5 older version, has been eliminated, can Not to be considered, but also outdated technology, the current market is mainly used in these versions. In the following article, let's look at the differences between these editions to let the reader know that we are not in a hurry to write code. Portal: Java SE 5 Portal: Java SE 6 Portal: Java SE 7 Portal: Java SE 8

First chapter: Java