Sun公司加快JDK的开发—JDK6u6以及JDK6u10Beta发布！

JDK6u6的内部版本号是1.6.0_06-b02，这次发布主要是修正了一些Bug。原文如下：
网址：http://java.sun.com/javase/6/webnotes/ReleaseNotes.html
Java SE 6u10Beta的发布则与众不同
  官方发文写到：千万不要被它不起眼的名字（即Java SE 6u10Beta，JDK6更新10Beta版本）所愚弄，它是一个与以前更新版本不同的“动物”（呵呵，有点奇怪哦，我觉得译成生命，或者语言）。它推出了比以往的任何java语言的更新，其中包括发布很久的，功能更强的拥有许多新特性的“信封”。
  以往，java更新版本的发布通常是个新闻稿，其中只有第四个版本号（ 10个1.6.0_10 ）的变化。不像其他的重大发布，更新版本不得添加，删除或改变任何公开的API ，一般来说这种情况限制了更新公告只包含bug修复。6u10同样包含任何新的或改变公共API的-但是，尽管这一限制，我们仍设法挤进了一些令人难以置信的新功能。
  这可是一次特别的更新！
  它针对一下做了改进：
  1、难以检测JREs，特别是Web浏览器
  2、新JREs难以自动安装
  3、下载量太大
  4、Applets和Web程序的不重叠
在以上改进的同时，他又避免了公共API的改变。你不用在等待Java7，我们可以很快得到修正！
  下面的太长了，大家还是自己看吧：）
Java Kernel

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The JRE provides many different APIs: Swing, AWT, ImageIO, SQL, CORBA, RMI, math, XML, XSLT, concurrency... too many to name, and each new release adds more. While the variety of APIs makes it easy to write Java software, it's no coincidence that the JRE has been getting steadily bigger over the years (Java 2 Platform, Standard Edition 1.5 was a smaller download due to better compression; the uncompressed JRE was still bigger).



Figure 1: JRE Size in MB



Java Kernel is a new distribution aimed at getting Java software up and running faster. Instead of a full JRE, users download a small installer (the "kernel") which includes the most commonly needed JRE components. Additional components are downloaded as needed, and the JRE will download remaining components in the background and then reassemble itself.



Figure 2: Kernel Size in MB



In the current build, the typical download size for Swing programs and Java applets is on the order of 4-5MB, compared to 14.4MB for the full JRE.


More information about Java Kernel can be found in the 6u10 FAQ.

Next-Generation Java Plug-In

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Java SE 6u10 includes a brand-new implementation of the Java Plug-in, which is used by default as long as you are using Firefox 3 or Internet Explorer. The next-generation plug-in runs applets outside of the browser in one or more separate processes. Applets still appear inside of the web browser window as they always have, but this means that it is now possible to use different JRE versions, command-line arguments, and configurations to run different applets. The isolation provided by running the web browser and the JRE -- two very large, very complex pieces of software -- in separate process spaces improves the reliability of both, and gives applets the same flexibility and control over JRE configurations that other Java software has always enjoyed.

Since applets now feature the same powerful JRE selection and configuration that Java Web Start programs do, it was only natural to use the same mechanism for both. The Java Plug-In now supports using Java Network Launching Protocol (JNLP) files to specify applet configuration and startup options. With very little additional work, you can now deploy the same program as both an applet and a Web Start program, and still take advantage of JNLP services such as PersistanceService and FileSaveService.

New Plug-In Advantages:

Improved reliability
Improved JavaScript communication
Per-applet control of JRE command-line arguments
Per-applet control of JRE memory settings, larger maximum heaps
JNLP support
Per-applet JRE version selection
Improved Vista support
Much more information about the new plug-in can be found in the release notes.

Java Deployment Toolkit

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The Java Deployment Toolkit makes deploying Java applets or Java Web Start programs a snap. The Deployment Toolkit JavaScript file provides:

Accurate detection of installed JREs
Seamless JRE installation
Complete applet launching (JRE detection and, if necessary, upgrading) in a single line of code
Complete Web Start program launching in a single line of code
The following HTML code is all it takes to ensure that Java 1.6 is installed and then a Java applet is launched:



Nimbus Look and Feel

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When the venerable Metal look and feel for Swing first debuted, its main aesthetic competition was the Windows 95 interface. Given the state of graphical user interfaces a decade ago, Metal was an attractive and elegant alternative to the other common interfaces of the time.

The updated Ocean theme in Java SE 5 helped to keep Metal a viable choice up to the present day, but it's time for Swing's cross-platform look and feel to get an overhaul.

Enter the Nimbus Look and Feel. A brand new, modern look and feel based on Synth, Nimbus provides a polished look to applications which choose to use it. And because Nimbus is drawn entirely using Java 2D vector graphics, rather than static bitmaps, it's tiny (only 56KB!) and can be rendered at arbitrary resolutions.



Figure 3: SwingSet3 in Metal





Figure 4: SwingSet3 in Nimbus



For compatibility reasons, Metal is still the default Swing look and feel, but updating applications to use Nimbus couldn't be simpler. It only takes a single line of code:

UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");You can also force Nimbus to be the default look and feel by specifying -Dswing.defaultlaf=com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel. on the command line. A more permanent way to set the property is to add

swing.defaultlaf=com.sun.java.swing.plaf.nimbus.NimbusLookAndFeelto the file <JAVA_HOME>/lib/swing.properties. You will have to create the swing.properties file if it does not already exist.

For further reading about Nimbus, take a look at the Nimbus early access page.

Performance

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Sun's JRE has been steadily getting faster over the years, and 6u10 is no exception. Key performance improvements are the introduction of Java Quick Starter, which will substantially improve Java cold start time on most systems, and a new graphics pipeline on Windows.

The new graphics pipeline will use Direct3D to accelerate most common operations, so the powerful 3D graphics card you probably have in your computer will have a use other than playing games. Translucency, gradients, affine transforms, antialiasing, rectangular fills and copies, and various other graphics operations will all be accelerated by 3D graphics cards. And, unlike previous 3D pipelines which were not robust enough to be enabled by default, the new pipeline is rock-solid and used by default in 6u10.

Read more about these features in Chet Haase's blog.

Improved Patching

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Java SE 6u10 includes improvements to patch downloading and installation. Of course this won't be visible until 6u11 shows up, but at that point the update will be downloaded by our new download engine, which monitors your network usage and throttles its bandwidth usage back to avoid interfering with your Internet usage.

The new download engine automatically resumes interrupted downloads, and 6u10 uses a new patching algorithm which will significantly reduce the size of future updates. Unlike current JREs, which prompt you as soon as an update becomes available and then make you wait during the download, 6u10 will download the patch in the background and only prompt for your permission to install when the download is already complete.

Deployment Usability

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Java Web Start has always supported versioned downloads, and both applets and Web Start have supported the use of Pack200 compression since it first appeared.

However, both of these features required server-side cooperation, which made them inherently difficult to work with. Even though the required servlets were provided and developers merely needed to install them, that unfortunately is not an option with many web hosts and the features were not as widely used as they might have been.

Starting in 6u10, both versioning and pack200 support are available without any special server support. You still have to enable the feature in the JNLP file or applet tag, but this is as easy as adding


But Wait, There's More!

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Like any Java update release, there are also a host of bugfixes, performance improvements, and usability improvements -- more than we can cover in any one article. Java SE 6u10 is the biggest update release (no public API changes) of Java software we have ever shipped, and the fact that there are no public API changes doesn't mean that you won't see anything to be excited about.

So what are you waiting for? The Java SE 6u10 beta is available as an early access download right now -- take a look and tell us what you think!


http://java.sun.com/developer/technicalArticles/javase/java6u10/index.html