Java, you know that cold knowledge?

1) There are many kinds of JVM, in fact the JVM is a standard, sun do that called Hotspot, the author is later V8 author Lars Bak, other companies have done the JVM, which do better have Bea JRockit, other including IBM's R9, Apple's JVM, and so on, does not work, so the JVM is primarily integrated to eliminate these poorly-done JVMs (s) and integrate them into a unified openjdk.

2) Java is a typical OOP language, its execution efficiency optimization, the first is Lars Bak and other people from the Smalltalk and other long-term optimization of the experience summed up and apply to the hotspot up drops, And Smalltalk in the early Apple machine on the kind of drag-and-drop to develop the practice of the app, and then Vc,delphi and so on is actually copied or borrowed from Apple's smalltalk approach, Jobs said that Microsoft from beginning to end copying Apple is unfounded, There is no place with the king of the groundless is a meaning, interestingly, the Java GUI did not inherit this pointers, but on this drag-and-drop to make the application of the criticism of the practice, to today, in fact, Java GUI can not really do drag-and-drop to make, a lot of problems, Personal suggestions for pure Java GUI Development, or write code-based.

3) Jee is a or a bunch of standards, know that some people to maven,jenkins is not a trickle, JEE standard core is EJB, is actually an XML configuration Java file, this standard in 4, reached the peak State, Almost all of the kicking Mills have actively supported the standard, and have since started to decline, with fewer and less supporting plants.

4) The relationship between Java and JavaScript is much closer than many people think, JavaScript Java Four letters are not white, such as JS's copyright and trademarks are controlled in Oracle's hands, Oracle's support for JS and even more than its support for Java, And like bundled sales, such as the JVM has a JS engine.

5) Inside the JVM there is a browser typesetting engine WebKit in addition to JS engine, which is the one used by Apple Safari and Google Chrome.

6) Java supports most scripting languages, you can call the name of the scripting language, almost all can be executed on the JVM, such as common Js,ruby,python, or even Php,lua, except JS you need to find the relevant scripting engine.

7) Spring's copyright is controlled in VMware's hands, in fact, spring's large pile of things, essentially a non-standard JEE implementation, such as the inject used in Jee, in spring is the Autowire, Of course, spring had a profound impact on JEE, so some things such as Di Standard, is the spring influenced by the formulation, so spring's approach will be more special.

8) Maven on the number of jars two days before the breakthrough 8 million, other languages of the class library, ranked second is NPM, the approximate number is Maven One-tenth, that is hundreds of thousands of, do not know now break 1 million no, then the gem, that is, Ruby that, about a hundred thousand of, Down is the Python module, about the order of magnitude is tens of thousands of, does not exceed 100,000.

9) Java standards are developed by an organization called JCP, and all standards need to be executed by JCP's executive committee, JCP almost all of the most well-known, kicking companies and organizations you know, such as google,apple,ibm,intel,arm,red Hat,twitter, and other educational institutions, such as China's Peking University, Ali recently applied to JCP Executive committee membership, it seems that the vote does not pass, the latest executive committee of two new members are arm and JetBrains.

10) Microsoft has also been a major contributor to JCP and even Java, but the interests of the drive, want to expand Java, so as to break the Java cross-platform features, so with sun falling, the essence is to let customers write Java code with Windows binding, sun resolutely disagree, fall out, Looking back to this result today, can only say: Double lose, Sun Hung, Microsoft's Ria is not too far away, Silverlight has given up, compared to the current year IE with the support of the JVM, that is completely different.

11) In addition to Microsoft, JCP also lacks an important organization Apache, because Apache and Oracle also fell out, Oracle does not seem to care about open source organizations, but more concerned about the support of commercial companies.

Java once had a built-in database that was stripped after 9.

J2ME is a subset of J2SE.

Vert.x author Tim Fox first saw node. js at the time that VMware did spring, sprouted the idea of making a multi-core node.x, and joined Red Hat to implement it after leaving VMware, and after VMware saw it began to Shuawulai, Claim node.x later changed to call Vert.x's copyright, regardless of with red Hat lawsuit, later the parties compromise, will give it to Eclipse Foundation.

Oracle before acquiring BEA, the first goal was not BEA and Bea WebLogic, but JBoss, but JBoss showed the very same side, before Oracle acquisition success, put Red Hat embrace, because are open source organization, Since JBoss became a sub-department of Red Hat, Oracle's takeover of JBoss failed and turned to Bea, Zhungshi Haoqi died, but it didn't work and was eventually maliciously acquired.

Sun's first attempt to reach the goal before it could not be played was that IBM,IBM was too expensive to give up and was handed over to Oracle.

Vert.x's author Tim Fox, who had been a Twitter complaint before leaving Red Hat, speculated that outsiders such as us were guessing that there was a jboss inside Red hat, so there was overlap with vert.x in the application, which led to the departure of Tim Fox, But after running away, Red Hat promised to make a sustained strategic investment in vert.x, so Vert.x Core's developers, in fact, is Red Hat's salary, but Vert.x's copyright is not in red Hat, and in eclipse Foundation in hand.

Several of Vert.x's core developers are Google Summer's mentor, who will enroll in college students at the beginning of each year.

19) Educational institutions Related: Scala's author Martin is German, ETH's guide, groovy's main leader is the French, JRuby behind is the University of Tokyo, JBoss author is the French school x alumni, X is not in the University of Galois, Galois can't enter X, So change to the Paris Normal University, Tim Fox graduated from Imperial Science and Technology, the Chairman went to that, Netty author Trustin Lee is ACM silver medal, now line work, graduated from the sky inside the Yonsei University, Kotlin is Mao subsidiary JetBrains works, see LinkedIn , many of whom graduated from St. Petersburg University, spring author Rod Johnson is a music doctor at the University of Sydney, and hibernate author Gavin King is a graduate of mathematics at Monash University in Australia, James Gosling this kind of CMU and Calgory estimate Rotten Street, Sun is the Stanford University Network meaning, entrainment two Sihuo, ASPECTJ has a maintenance team in mcgill,hbase with Waterloo closely.

Java early was considered slow, with Java insisted not hardware accelerated rendering related, dead and alive is refused to access DirectX and opengl,7 after finally enlightened, engaged in a graphics engine access to the DIRECTX/OPENGL.

Casssandra is a project that Facebook has failed to do, and has been contributed to the old tree after the Apache flowering.

Groovy was contributed to Apache, now called Apache Groovy,ceylon, and is now called Eclipse Ceylon.

Netflix is now a Java shop, previously using. Net.

Think of so much first, and write again when you are free.

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Java, you know that cold knowledge?