The first chapter of the development process of Java (1.1)
The Java (computer programming language)
the Java is an object-oriented programming language, not only absorbed the
C++
various advantages of language, also abandoned
C++
in incomprehensible
Multiple inheritance、
pointer
Concepts, so
Java
the language has
Powerful
with
Easy to use
Two characteristics.
Java
Language, as a representative of static object-oriented programming language, implements object-oriented theory extremely well, allowing programmers to perform complex programming in an elegant way of thinking.
Java
have
Simplicity
、
Object-oriented
、
distributed
、
Robustness
、
safety
、
Platform independent
、
portability
、
Multithreading
with
Dynamic
Features.
Java
Can write
Desktop application
、
Web application
、
Distributed Systems
with
Embedded system applications
Wait.
1.1, the development process of Java
In the 1990s , a single-chip computer system appeared in the hardware field. As soon as this low-cost system appeared, it immediately attracted the attention of people in the field of automatic control, because the use of it can greatly improve consumer electronic products (such as TV set-top boxes, The degree of intelligence of bread ovens, mobile phones, etc.). Sun company in order to seize market opportunities, in 1991 established a program calledGreenThe project team of Patrick, James Gosling , Mike Shelindane and several other engineers worked together in a small studio on Dune Road in Menlo Park, California to research and develop new technologies, specializing in computers and home appliances. Embedded applications on the Internet.
Due to the advantages of C++, the researchers of the project group first considered using C++ to write programs. But for a monolithic system with extremely scarce hardware resources, C++ programs are too complex and huge. In addition, due to the various types of embedded processor chips used in consumer electronics products, how to make programs written to run across platforms is also a problem. In order to solve the difficulties, they first focused on the development of the language, assumed a hardware platform architecture with a simple structure and meeting the needs of embedded applications and formulated corresponding specifications for it, which defined the hardware platformBinary machine code instruction system(That later became the "bytecode" instruction system). After the language is successfully developed, semiconductor chip manufacturers can develop and produce this hardware platform. For the design of the new language, Sun's R&D staff did not develop a brand-new language, but modified C++ according to the requirements of embedded software, removing some of the less practical and safety-related components left in C++. And combined with the real-time requirements of embedded systems, a system calledOak(OAK, English word, noun, adjective, when used as a noun, it means "oak tree; oak color; oak furniture, name; (English) Oak", when used as an adjective, it means "oak tree; oak wood".) Object-oriented language.
Due to developmentOakLanguage, there is no hardware platform for running bytecode, so in order to conduct experimental research on this language during development, they use software based on the existing hardware and software platform and in accordance with their own specified specifications. A running platform has been built, and the whole system is not much different except that it is simpler than C++. In the summer of 1992 , when the Oak language was successfully developed, researchers demonstrated to hardware manufacturersGreen operating system、Oak's programming language、Class libraryAnd itshardware, In order to persuade them to use Oak language to produce hardware chips, but the hardware manufacturers did not have great enthusiasm for this. Because they believe that the risk of producing hardware products is too great when everyone knows nothing about the Oak language, so the Oak language cannot enter the market due to lack of hardware support, and thus it is shelved. .
In June and July 1994 , after a three-day discussion, the team decided to change the goal of their efforts again. This time they decided to apply the technology toWorld Wide Web. They think withMosaic browserWith the advent of the Internet, the Internet is evolving towards the same highly interactive vision, and this vision is exactly what they saw in the cable TV network. As a prototype, Patrick Norton wrote aSmall World Wide Web Browser WebRunner。
In 1995 , the booming development of the Internet gave Oak an opportunity. In order to make the industry rigid and monotonousStatic pagesTo be "flexible", there is an urgent need for a software technology to develop a program that can be spread through the network and can run across platforms. As a result, the world's major IT companies have invested a lot of manpower, material resources and financial resources for this. At this time, Sun company thought of the one that had been shelved for a long timeOak, And re-examined the test platform written in software. Because it is written in accordance with the hardware platform architecture of the embedded system, it is very small and especially suitable for transmission systems on the network. Oak is also a streamlined language. The program is very small and suitable for transmission on the network. Sun company first introduced a web page that can be embedded in a web page and can be transmitted on the Internet along with the web page.Applet(Applet is a technology that embeds applets into web pages for execution), and renamed Oak to Java (when applying for a registered trademark, I found that Oak had already been used, and after thinking about a series of names, I finally used This is the Java term that the proposer accidentally mentioned when drinking a cup of Java coffee). On May 23 , Sun officially announced at the Sun World ConferenceJavawithHotJava browser. Major companies such as IBM, Apple, DEC, Adobe, HP, Oracle, Netscape, and Microsoft have stopped their related development projects, rushed to purchase Java licenses, and developed corresponding products for their own products.Java platform。
In January 1996 , Sun released the first JavaDevelopment kit(JDK 1.0), this is an important milestone in the development of Java, marking that Java has become an independent development tool. In September , about 83,000 web pages were produced using Java technology. In October , Sun released the first Java platformJust-in-time (JIT) compiler。
In February 1997 , JDK 1.1 came out, and in the following three weeks, it reached 220,000 downloads. On April 2 , the Java One conference was held, with more than 10,000 participants, which was the world's largest conference of its kind at that time. In September , the Java Developer Connection community had more than 100,000 members.
On December 8, 1998, the enterprise version of the second-generation Java platformJ2EErelease. In June 1999 , Sun released three versions of the second-generation Java platform (referred to as Java2):
- J2ME(Java2 MicroEdition, the micro version of the Java2 platform), used in mobile, wireless and limited resource environments ;
- J2SE(Java 2 Standard Edition, the standard edition of the Java 2 platform), applied to the desktop environment ;
- J2EE(Java
2 Enterprise Edition, the enterprise edition of Java 2 platform), applies to the application server based on Java .
The release of the Java 2 platform is the most important milestone in the development of Java, marking the beginning of the popularization of Java applications.
On April 27, 1999 ,HotSpot virtual machinerelease. When the HotSpot virtual machine was released, it was provided as an add-on program to JDK 1.2. Later, it became the default virtual machine for JDK 1.3 and all later versions of Sun JDK.
In May 2000 , JDK1.3, JDK1.4 and J2SE1.3 were released one after another. A few weeks later, they were supported by Apple's Mac OS X industry standard.
On September 24, 2001 , J2EE1.3 was released.
On February 26, 2002 , J2SE1.4 was released. Since then, the computing power of Java has been greatly improved. Compared with J2SE1.3, it has nearly 62% more classes and interfaces. Among these new features, a wide range ofXMLstand by,Secure socket(Socket) support (through SSL and TLS protocol), brand newI/OAPI、Regular expression、LogversusAffirmation。
On September 30, 2004 , J2SE1.5 was released, becoming another milestone in the history of Java language development. In order to express the importance of this version, J2SE 1.5 was renamed Java SE 5.0 (internal version number 1.5.0), codenamed "Tiger", Tiger contains the most significant updates since the 1.0 release in 1996, includingGenericstand by,Basic type of automatic boxing、Improved loop、Enumerated type、Format I/Oandvariable parameter。
In June 2005 , at the Java One conference, Sun released Java SE 6. At this time, various versions of Java have been renamed , and the number 2 has been cancelled. For example, J2EE was renamed JavaEE, J2SE was renamed JavaSE, and J2ME was renamed JavaME.
On November 13, 2006 , Sun, the inventor of Java technology, announced that it would release Java technology as free software . Sun officially released the first batch of source codes for the Java Platform Standard Edition and the executable source code for the Java Mini Edition. Since March 2007 , all developers around the world can modify the Java source code.
In 2009 , Oracle announced the acquisition of Sun .
In 2010, James Gosling , one of the co-founders of the Java programming language, resigned from Oracle .
In 2011 , Oracle held a global event to celebrate the launch of Java7, and then Java7 was officially released.
In 2014 , Oracle released the official version of Java 8.