1.1 A brief History of Java language development

The birth of the Java language has a certain drama, it is not carefully planned, produced, the final production of epoch-making products, from an angle engaging, the birth of the Java language is completely a misunderstanding.

By the end of 1900, Sun expects embedded systems to be in the field of future appliances. So sun set up a "Green program" led by James Gosing to prepare a universal control system for next-generation smart appliances such as televisions, microwaves, and telephones.

The team initially considered using the C + + language, but many members, including Sun's chief scientist, Bill Joy, found that C + + and the available APIs had big problems in some ways. And the Working Group is using an embedded platform. The available system resources are extremely limited. And many members found that C + + was too complex for many developers to use incorrectly. and C + + lacks garbage collection system, portability, distributed and multithreading functions.

Based on the funds available, Bill Joy decided to develop a new language, and he proposed to develop an object-oriented environment based on C + +. As a result, Gosling tried to satisfy this requirement by modifying and extending the functionality of C + +, but later he gave up. He decided to create a new language: Oak.

By the summer of 1992, the green program has completed some of the features of the new platform, including the green operating system, Oak's programming language, underwear, etc. In November, the green project was transformed into "Firstperson Limited", a wholly-owned subsidiary of Sun Corporation.

The Firstperson team is committed to creating a highly interactive device. When Time Warner released a request for a proposal for a TV set-top box, Firstperson changed their goal, as a response to the request for proposals, proposed a set-top box. But the limited TV industry felt Firstperson his platform gave users too much control, so Firstperson's bid was defeated by SGI. At the same time, another deal with the 3DO company about the set-top box was unsuccessful. At this point, the poor green project almost died, and even half of the Green project team was transferred to other projects.

As the proverb in ancient China says: disguise, how do you know not to be blessed? If the green project bids successfully on the set-top box platform, it may not be a great language to be born in Java.

In the summer of 1994, the advent of Internet and browser not only brought the gospel to the users of the Internet, but also brought new vitality to the oak language. Gosling immediately realized that this was an opportunity, so the oak was transformed to a small scale, and by the fall of 1994, the group of Naunghton and Gonathan Payne completed the first Java language Web browser: Webrunner. Eric Schmidt, director of the Sun's lab, Bert Sutherland and technical director, watched the browser's presentation and gave a highly rated view of the browser's performance. When Oak was registered, it had to be renamed Java.

Sun Company released the Java language in early 1995, sun company directly put Java on the Internet, free for everyone to use. Even the source code is not confidential, and it is placed on the internet for all to the public.

A few months later, something that surprised everyone: JVA became the hottest baby on the internet. More than 100,000 people visited the Sun Company's web page and downloaded the Java language. Then, the Internet immediately on the countless Java applets (that is, applets), cover up a variety of small animation, small games and so on.

Finally, the Java language became a widely known programming language.

Before the advent of the Java language, the Web page of the Internet was essentially a piece of paper, without any dynamic content. With the Java language, the function of the browser is expanded, the Java program can be directly in the browser to run, can directly interact with the remote server, in the Java language programming, can be sent on the Internet as easy as e-mail to transfer program Files!

In 1995, Sun released JDK 1.1 on February 18, 1997. JDK 1.1 adds a JIT (instant compile) compiler. Unlike a traditional compiler, a traditional compiler compiles a piece of code, throws it away after it is finished, and the JIT saves the frequently used instructions in memory, and when the next call does not need to be recompiled, it makes the JDK more efficient.

But all along, Java's main applications are applets on the web and some mobile devices. By the end of the year 1996, Flash was unveiled, a simpler animation design software, with flash almost without any programming language knowledge to make colorful animations. Then flash added ActionScript programming scripts, and Flash gradually eroded Java's application on the web.

From the birth of Java in 1995 to the end of 1998, the Java language became a widely used programming language on the Internet, but it did not find an accurate location, nor did it find a reason for it to exist; the Java language can write applets, which Flash can do, and faster and lower development costs.

Until December 1998, Sun released the most important JDK version of Java history, and JDK 1.2 was released along with JDK 1.2, with specifications such as Jsp/servlet, EJB, and Java into three versions of EE, J2SE, and J2ME.

• J2ME: Mainly used to control mobile devices and information appliances and other mailbox storage devices.

• J2SE: The core and foundation of the entire Java technology, which is the foundation of J2ME and J2SE programming, and the main content of this book.

• The most widely used part of J2ee:java technology, the Java EE provides a complete solution for enterprise application development.
  

This marked the launch of Java into the enterprise, desktop and mobile 3 areas of the horn, marking the Java has entered the Java 2 era, this period is the rapid development of Java period.

In Java 2, there have been a lot of revolutionary changes in Java, and these revolutionary changes have been used to the present, the development of Java has a profound impact. Until today, we also often see the Java EE, J2ME and other nouns.

Not only that, JDK 1.2 also divides its API into three main categories.

• Core API: The basic API developed by Sun, which all Java platforms should provide. This is what we usually call the Java core underwear.

• Optional API: This is the extension API that Sun provides to the JDK, and these APIs vary from one platform to the other.

• Special API: An API to meet special requirements. such as third-party cryptographic class libraries for JCA and JCE.
  

In February 2002, Sun released the most mature version of the JDK's history; JDK 1.4. With the participation of Compaq, Fujitsu, SAS, Symbian and IBM, JDK 1.4 has become the fastest-growing JDK version. By the end of JDK 1.4, we can already use Java to implement most applications.

During this time, the Java language in the enterprise applications, the emergence of a large number of Java-based open source framework, Struts, WebWork, Hibernate, Spring, and so on, a large number of enterprise application servers are also beginning to emerge: Weblogic, WebSphere, JBoss and so on, these all mark the Java language into the rapid development period.

In October 2004, Sun could not send the most anticipated JDK 1.5, while Sun renamed JDK 1.5 to Java SE 5.0,j2ee, and J2ME also renamed Java EE and Java ME accordingly. JDK 1.5 adds features such as generics, enhanced for statements, variable number of parameters, annotations (Annotations), automatic unpacking and boxing, and new enterprise platform specifications, such as commenting on the complexity of EJBS with new features such as annotations, and introducing the EJB 3.0 specification. It also introduced its own MVC framework specification, and the JSF,JSF specification is similar to the ASP. NET-based server control, which allows you to quickly build a complex JSP interface.

In December 2006, Sun released JDK 1.6 (also known as Java SE 6). Sun has maintained its habit of releasing a new version of the JDK for about 2 years.

But on April 20, 2009, Oracle announced it would buy Sun at $9.5 a share, with a total value of about $7.4 billion. Oracle acquired two software assets: Java and Solaris, by acquiring Sun.

So once represented an era of the company: Sun was finally "blowing wind blows" to go, "lakes and rivers" on the sun is no longer figure. Over the years, the new generation of programmers may forget the sun company, but the old-timers will permanently miss the legend of Sun.

Sun has fallen, but the banner of Java is still "fluttering". In November 2007, Google announced the highlight of a Linux-based platform for the open-source mobile phone operating system, Android. Android's emergence is in tune with the upcoming mobile internet trend, and the Android system's user experience is very good, so it quickly becomes the backbone of the mobile phone operating system. The Android platform uses the Dalvik virtual machine to run the. dex file, and the Dalvik virtual machine acts like a JVM virtual machine, except that he does not comply with the JVM specification. Android uses the Java language to develop applications, which gives the Java language a new opportunity. The Java language has been a great success in the past years as a server-side programming language, and the popularity of the Android platform has allowed the Java language to gain a chance to be a part of the client program.

July 28, 2011, Oracle Company finally "as-is" to not be able to send Java SE 7--This version of the upgrade after nearly 5 years of time. Java SE 7 is also the first version of Java published by Oracle. Java SE 7 does not fully meet everyone's expectations, but it also adds a number of new features, which are described in more detail later in this book.

1.1 A brief History of Java language development