Mikael Olsson - Java 17 Quick Syntax Reference: A Pocket Guide to the Java SE Language, APIs, and Library

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Java is a high-level object-oriented programming language developed by Sun Microsystems, which became part of Oracle Corporation in 2010. The language is very similar to C++ but has been simplified to make it easier to write bug-free code. Most notably, unlike C++, there are no pointers in Javainstead, all memory allocation and deallocation is handled automatically.

Despite simplifications like this, Java has considerably more functionality than C++, due to its large class library. Java programs also have high performance and can be made very secure, which has contributed to making Java the most popular general-purpose programming language in use today.

Another key feature of Java is that it is platform independent. This is achieved by only compiling programs halfway, into platform-independent instructions called bytecode. The bytecode is then interpreted, or run, by the Java Virtual Machine (JVM) . That means any system that has this program and its accompanying libraries installed can run Java applications.

To allow Java to be used in a variety of environments, there are four different editions : Java ME, Java SE, Java EE, and Java FX. Each edition contains a JVM and a set of class libraries. Java SE (Standard Edition) provides the standard JVM along with the commonly used libraries for building applications, in particular desktop applications. Java ME (Micro Edition) is a small-footprint version of Java SE designed for running on small devices such as mobile phones. Java EE (Enterprise Edition) is an extended version of Java SE that includes libraries for building large-scale web applications. The most recently added edition is JavaFX, a lightweight version intended for building desktop and rich web applications. This edition includes a new library for making graphical user interfaces (GUIs) , which is intended to replace the standard GUI library called Swing used in Java SE.

To allow Java to be used in a variety of environments, there are four different editions: Java SE, Java ME, Java EE, and Java FX. Each edition contains a JVM and a set of class libraries. Java SE (Standard Edition) provides the standard JVM along with the commonly used libraries for building applications, in particular desktop applications. Java ME (Micro Edition) is a small-footprint version of Java SE designed for running on small devices such as mobile phones. Java EE (Enterprise Edition) is an extended version of Java SE that includes libraries for building large-scale web applications. The most recently added edition is Java FX, a lightweight version intended for building rich web applications.

The Java language and class libraries have undergone major changes since their initial release in 1996. The naming conventions for the versions have gone through a few revisions as well, mainly for marketing reasons. The major releases include JDK 1.0, JDK 1.1, J2SE 1.2, J2SE 1.3, J2SE 1.4, J2SE 5.0, followed by Java SE 6 to Java SE 17, with Java SE 17 being the current version as of writing. For the sake of simplicity, the Java versions will be referred to as Java 117 in this book. Note that Java is designed to be backward-compatible. Therefore, the Virtual Machine for Java 17 can still run Java 1 applications.