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Java programming language.

Origin1

The seeds of Java were planted in 1990 by Sun Microsystems patriarch and chief researcher Bill Joy. At the time, Sun was competing in a relatively small workstation market, while Microsoft was beginning its domination of the more mainstream, Intel-based PC world. When Sun missed the boat on the PC revolution, Joy retreated to Aspen, Colorado, to work on advanced research. He was committed to the idea of accomplishing complex tasks with simple software and founded the aptly named Sun Aspen Smallworks.

Of the original members of the small team of programmers Joy assembled in Aspen, James Gosling will be remembered as the father of Java. Gosling first made a name for himself in the early 1980s as the author of Gosling Emacs, the first version of the popular Emacs editor that was written in C and ran under Unix. Gosling Emacs was soon eclipsed by a free version, GNU Emacs, written by Emacs’s original designer. By that time, Gosling had moved on to design Sun’s Network extensible Window System (NeWS), which briefly contended with the X Window System for control of the Unix GUI desktop in 1987. Although some people would argue that NeWS was superior to X, NeWS lost because Sun kept it proprietary and didn’t publish source code, while the primary developers of X formed the X Consortium and took the opposite approach.

Designing NeWS taught Gosling the power of integrating an expressive language with a network-aware windowing GUI. It also taught Sun that the internet programming community will ultimately refuse to accept proprietary standards, no matter how good they may be. NeWS’s failure sowed the seeds of Java’s licensing scheme and open (if not quite “open source”) code. Gosling brought what he had learned to Bill Joy’s nascent Aspen project. In 1992, work on the project led to the founding of the Sun subsidiary FirstPerson, Inc. Its mission was to lead Sun into the world of consumer electronics.

The FirstPerson team worked on developing software for information appliances, such as cellular phones and personal digital assistants (PDAs). The goal was to enable the transfer of information and real-time applications over cheap infrared and traditional packet-based networks. Memory and bandwidth limitations dictated small, efficient code. The nature of the applications also demanded they be safe and robust. Gosling and his teammates began programming in C++, but they soon found themselves confounded by a language that was too complex, unwieldy, and insecure for the task. They decided to start from scratch, and Gosling began working on something he dubbed “C++ minus minus.”

With the foundering of the Apple Newton (Apple’s earliest handheld computer), it became apparent that the PDA’s ship had not yet come in, so Sun shifted FirstPerson’s efforts to interactive TV (ITV). The programming language of choice for ITV set-top boxes was to be the near ancestor of Java, a language called Oak. Even with its elegance and ability to provide safe interactivity, Oak could not salvage the lost cause of ITV. Customers didn’t want it, and Sun soon abandoned the concept.

At that time, Joy and Gosling got together to decide on a new strategy for their innovative language. It was 1993, and the explosion of interest in the web presented a new opportunity. Oak was small, safe, architecture independent, and object-oriented. As it happens, these are also some of the requirements for a universal, internet-savvy programming language. Sun quickly changed focus, and, with a little retooling, Oak became Java.

Type system

Java provides some of the benefits of both C++ and Smalltalk; it’s a statically typed, late-binding language. Every object in Java has a well-defined type that is known at compile time. … However, Java is fully runtime-typed as well. … This means you can inspect an object at runtime to determine what it is.1

Relationships with OpenJDK

Since 2017, Oracle has officially supported updates to the open source OpenJDK.1

Changes since Java 5 (a.k.a. JDK 1.5)

  • Java 6, released in late 2006, was a relatively minor release that added no new syntactic features to the Java language but bundled new extension APIs such as those for XML and web services.
  • Java 7, released in 2011, represented a fairly major update. Several small tweaks to the language such as allowing strings in switch statements (more on both of those things later!) along with major additions such as the java.nio new I/O library were packed into the five years after the release of Java 6.
  • Java 8, released in 2014, completed a few of the features such as lambdas and default methods that had been dropped from Java 7 as the release date of that version was delayed again and again. This release also had some work done to the date and time support, including the ability to create immutable date objects, handy for use in the now-supported lambdas.
  • Java 9, released after a number of delays in 2017, introduced the Module System (Project Jigsaw) as well as a Read-Evaluate-Print Loop (REPL) for Java: jshell. We’ll be using jshell for much of our quick explorations of many of Java’s features throughout the rest of this book. Java 9 also removed JavaDB from the JDK. Added ahead-of-time (AOT) compilation.
  • Java 10, released shortly after Java 9 in early 2018, updated garbage collection and brought other features such as root certificates to the OpenJDK builds. Support for unmodifiable collections was added, and support for old look-and-feel packages (such as Apple’s Aqua) was removed.
  • Java 11, released in late 2018, added a standard HTTP client and Transport Layer Security (TLS) 1.3. JavaFX and Java EE modules were removed. (JavaFX was redesigned to live on as a standalone library.) Java applets were also removed. Along with Java 8, Java 11 is part of Oracle’s long-term support (LTS). Certain releases—Java 8, Java 11, Java 17, and Java 21—will be maintained for longer periods of time. Oracle is trying to change the way customers and developers engage with new releases, but good reasons still exist to stick with known versions. You can read more about Oracle’s thoughts and plans for both LTS and non-LTS releases at the Oracle Technology Network’s Oracle Java SE Support Roadmap.
  • Java 12, released in early 2019, added minor language syntax enhancements such as a switch expressions preview.
  • Java 13, released in September 2019, includes more language feature previews, such as text blocks, as well as a big reimplementation of the Sockets API. Per the official design docs, this impressive effort provides “a simpler and more modern implementation that is easy to maintain and debug.”
  • Java 14, released in March 2020, added more language syntax enhancement previews such as records, updated the garbage collection feature, and removed the Pack200 tools and API. It also moved the switch expression first previewed in Java 12 out of its preview state and into the standard language.
  • Java 15, released in September 2020, moved support for text blocks (multiline strings) out of preview, and added both hidden and sealed classes that allow new ways to restrict access to certain code. (Sealed classes were kept as a preview feature.) Text encoding support was also updated to Unicode 13.0.
  • Java 16, released in March 2021, kept sealed classes in preview but moved records out of preview. Networking APIs were expanded to include Unix domain sockets. It also added a list output option to the Streams API.
  • Java 17, released in September 2021 with LTS, upgraded sealed classes to a regular feature of the language. A preview of pattern matching for switch statements was added along with several improvements on macOS. Datagram sockets can now be used to join multicast groups.
  • Java 18, released in March 2022, finally made UTF-8 the default character set for Java SE APIs. It introduced a simple, static web server appropriate for prototyping or testing, and expanded the options for IP address resolution.
  • Java 19, released in September 2022, previewed virtual threads, structured concurrency, and record patterns. Unicode support moved to version 14.0, and some additional date-time formats were added.
  • Java 20, released in March 2023, finally removed several threading operations (stop/pause/resume) that were deprecated as unsafe over 20 years earlier in JDK 1.2. String parsing was improved to support graphemes, such as composed emoji symbols.
  • Java 21.
  • Java 22.
  • Java 23.

See also:

Footnotes

  1. Chapter 1, Learning Java, 6th edition ↩ ↩2 ↩3

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