Java technology has passed the time of 9 years. As a reporter who has been paying attention to its growth, I have had such an idea for a while: "Java technology has matured, is it a speed of development?" However, this idea is wrong. Recent evolution of Java technology has been quite significant. Java technology is welcoming the "another revolution" storm. This is the conclusion of this article.
What is "another time"? What is the "revolution" refers to? If the light is concerned, it must be a mist. In fact, the author is not to change this fact, but "promoting the power of change". What makes Java technology change? Let us start from this angle, first look at the process of change in Java.
Java is in a transition period
Review the development of JAVA technology, people will feel this: 2004 to 2005 changes are so large, can say "now" is the conversion period of Java technology. Java technology consists of a programming language (Java language), the operating environment (JVM: Java virtual machine), the framework (Java API group), and a huge change in every level.
(1) Changes in programming languages
Java language standards have changed significantly. In September 2004, official version J2SE5.0 (J2SE: Java2 Platform, STANDARD Edition, Java technology core running environment), the generics in Java Language standards has been greatly expanded from metadata. There was a "largest language standard change since Java" (US Sun Microsystems). The changes in this language standard have brought an impact on many Java APIs. The new version of many enterprise APIs is introduced into metadata-based annotations (additional information recorded in the program) to describe more information with shorter encoding.
(2) Changes in Java operating environment
In J2SE 5.0, the management function and practicality of JVM is largely enhanced, and in other words, the Java execution OS (operating system) feature is equipped. For example, the standard is equipped with application software management framework JMX as a management function in J2EE (Java2 Platform, Enterprise Edition, Building Enterprise System Java Technology). Not only that, but also equipped with JVM self-monitoring ((JSR 174: Monitoring and Management Specification for the Java Virtual Machine). You can monitor the status of JVM run in real time in the standard function architecture, which is the amount of memory usage, thread state, etc.
The newly added functions in J2SE 5.0 include parallel processing utilities (JSR 166), which is the base library provided by DOUG LEA in New York State University. That is, the standard specification uses a library from the people.
(3) Changes in the framework
The server-side Java framework has also changed. Enterprise Java Technology - J2EE "J2EE BluePrint" in "J2EE Blueprint" proposed a framework of the application software into a web layer, EJB layer (Enterprise JavaBeans, will include a transaction process modular framework) Come to build the idea. These two levels have ushered in the architecture replacement period. The new frame of the web layer is JSF (JavaServer Faces, combining the module to construct the framework of the web application), and the EJB layer is the next-generation EJB specification "EJB3.0" just announced in the standard scheme.
It is worth noting that it is the source code open software from the folk frame. The impact on JSF is a popular APACHE STRUTS that is a WEB layer framework that is open as a source code. JSF is a product of Struts's ideas, one of JSF's Spec LEAD (Specifications Developer Leaders) Craig R. McClanahan is the author of Struts.
The impact on EJB3.0 is also the open software of private code. EJB3.0 introduces the new features of Di (Contaendency Injection, dependency injection) container class (Plain Old Java Object) persistent, which greatly reduces the complexity of programming. These concepts are eye-catching because of the import of PicoContainer, Spring and other source code open software.
Its background is the user's criticism for "current EJB is too complex". The design idea and source open software originally proposed by the EJB opposition, but it turned into the central concept of EJB3.0, which has shown great influence.
(4) Script language
The programming language Groovy (JSR 241) is added in Java Technical Standards. This is a scripting language that can be seamlessly connected to the Java language, which is expected to complete related processing with a very short program. "Language adding Java outside Java technology", which sounds some awkward, in fact, there is such a voice, I hope to make full use of the script of Java technology resources as language. Groovy was originally the source opening software, eventually recognized, and was adopted as a standard specification.
As can be seen from the above, the constituent elements of Java technology are changing. Not long ago, a document that lifted the server Java, "Servlet, JSP, EJB is important API" also accounts for mainstream, but now JSF and EJB3.0-based applications have become "unrecognizable" procedures. When running short programs or test, even there is not only Java language, and the scripting language begins to call the Java framework.
These changes can be seen from the big aspects, which can be said to have further played the advantage of the Java object-oriented. Of course, it also includes the advantages of improving development efficiency, improving operational stability, and simplifying operation management.
The developer group is a real "change driver"
So, where is these changes from these changes? Why say "currently" is facing "another change"? The reasons are as follows:
During the development of Java technology, 1999 to 2000 is a big turning point. J2EE concept appeared in 1999. J2EE is also popular in 2 to 3 years, but this technology system has been established 5 years ago. In front of us, the outline of the new generation of Java technology is gradually displayed.
JAVA Community Process 2.0 in 2000. Promoting the specifications of Java technology in the form of a member system, and the overall development direction is determined by the Committee. Thereby forming a specifications that do not rely on specific companies. This organizational form has gradually developed into "transformation promoters" after nearly five years.
J2EE has been criticized before, and believes that "the gap between the Web layer and the EJB layer is too large", "EJB is too complex", but this is because this is a practical technology. JCP also encountered a lot of criticism, saying that it is "not fully open", "the technical standards developed" is incredible to make Sun have intellectual property, but JCP has continued to grow as a group.
Directly promoting the changes of Java technology to group-based standards formulated five years ago - JCP, but truly discussions and techniques include JAVA developer groups including Java technology critics. They are also the pioneer of Java technology change earlier. The next-generation technology that is born will gradually affect mainstream enterprise users after 2 to 3 years.
