Looking forward to Java 7

Dolphin will not be released in 2007. Next year is a more realistic goal. That said, work is underway and some features may make their debut as standard extensions earlier, or at least as betas.

我也觉得必须要留够时间给Mustang来折腾折腾啊，要是弄得和Tiger一样短命且孤芳自赏的话，SUN和一干Java幕后势力的面子也不好看哟。

It's unfortunate that it's far, far easier to add features to a language than to take them away. Almost inevitably, languages get more complex and confusing over time, not less. Even features that look good in isolation become problematic when piled on top of each other.

Unfortunately, the Java community has not yet learned this lesson, despite the debacle that is generics. There's just something about new syntax that's too cool and exciting for language designers to resist, even when it doesn't solve any actual problems. Thus the huge clamor for new language features in Java 7, including closures, multiple inheritance, and operator overloading.

I suspect that before the year is out we will see closures in a Java 7 beta, and we may well see operator overloading (50/50 chance), but multiple inheritance simply will not happen. Too much of Java is based on a singly rooted inheritance hierarchy. There's no plausible way to retrofit multiple inheritance into the language.

Currently there's a lot of syntax sugar on the table, some of which makes sense, some of which doesn't. A lot of the proposals focus on replacing methods like getFoo() with operators like ->.

• Lists

The first possibility is using array syntax for collections access. For example, instead of writing this:

List content = new LinkedList(10);
content.add(0, "Fred");
content.add(1, "Barney");
String name = content.get(0);

you could instead write this:

List content = new LinkedList(10);
content[0] = "Fred";
content[1] = "Barney";
String name = content[0];

Another possibility is allowing array initializer syntax for lists. For example:

LinkedList content = {"Fred", "Barney", "Wilma", "Betty"}

Both of these proposals could be implemented with a little compiler magic without changing the virtual machine (VM), an important characteristic for any revised syntax. Neither proposal would invalidate or redefine any existing source code, an even more important issue for new syntax.

One language feature that might make a real difference in developers' productivity would be built-in primitives for managing tables, trees, and maps, such as you encounter when working with XML and SQL. Projects like E4X in JavaScript land and Cω and Linq in the Microsoft world are pioneering this idea, but sadly, the Java platform seems to be missing the boat. If anyone feels like making a potential game-saving play by forking the compiler, here is a very good place to look.

• Properties

We'll probably also see some syntax sugar for property access. One proposal is to use -> as a shorthand for calling getFoo and setFoo. For example, instead of writing:

Point p = new Point();
p.setX(56);
p.setY(87);
int z = p.getX();

you could write"

Point p = new Point();
p->X = 56;
p->Y = 87;
int z = p->X;

Other symbols including . and # have also been proposed in lieu of ->.

In the future, you may or may not have to explicitly identify the relevant field as a property in the Point class, like so:

public class Point {

    public int property x;
    public int property y;

}

Personally, I'm underwhelmed. I'd like to see the Java platform adopt a more Eiffel-like approach in which we could actually use public fields. However, if getters or setters are defined with the same names as the fields, then reads and writes to the fields are automatically dispatched to the methods instead. It uses less syntax and it's more flexible.

• Arbitrary precision arithmetic

Another proposal to replace methods with operators aims at BigDecimal and BigInteger. For example, currently you have to code unlimited precision arithmetic like so:

BigInteger low  = BigInteger.ONE;
BigInteger high = BigInteger.ONE;
for (int i = 0; i < 500; i++) {
    System.out.print(low);
    BigInteger temp = high;
    high = high.add(low);
    low = temp;
};

BigInteger low  = 1;
BigInteger high = 1;
for (int i = 0; i < 500; i++) {
    System.out.print(low);
    BigInteger temp = high;
    high = high + low;
    low = temp;
};

• Taking the JAM out of the JAR

Java 7 could fix the most long-standing source of irritation to Java developers: the various class loaders and associated classpaths. Sun is taking another whack at this problem with the Java Module System. Instead of a .jar file, data will be stored in a .jam file. This is a sort of "superjar" that contains all the code and metadata. Most importantly, the Java Module System will support versioning for the first time, so you can say that a program needs Xerces 2.7.1 but not 2.6. It will also allow you to specify dependencies; for instance, to say that the program in the JAM requires JDOM. It should also enable you to load one module without loading them all. Finally, it will support a centralized repository that can provide many different versions of many different JAMs, from which applications can pick the ones they need. If the JMS works, jre/lib/ext will be a thing of the past. 

(Jam 也有果酱的意思，不知道这个甚至可以支持版本化的"superjar"能不能得到大家的认同。在我看来，它确实有够前卫的啊！)

• Package access

I'm also hopeful that Java 7 will relax access restriction just a bit. It may become possible for subpackages to see the package-protected fields and methods of classes in their superpackages. Alternately, it may be possible for subpackages to see the package-protected members of superpackages that explicitly declare their friendliness. Either way, this would make dividing an application into multiple packages much simpler and dramatically improve testability. As long as unit tests were in a subpackage, you wouldn't have to make methods public to test them.

(包的作用将会在Java 7中会有一些变化/改进？这样一来，对象在方法和属性在声明的时候兴许能够变得灵活一些……)

• Filesystem access

Filesystem access has been a major problem for the Java platform since 1995. More than 10 years later, there's still no reliable cross-platform way to perform basic operations like copying or moving files. Fixing this has been an open issue for at least the past three JDKs (1.4, 5, and 6). Sadly, boring but necessary APIs for moving and copying files have been shunted aside in favor of less common but sexier operations like memory-mapped I/O. Possibly JSR 203 will finally fix this and give us a plausible, cross-platform file system API. Then again, the working group may once again spend so much time on the relatively unimportant problem of true asynchronous I/O that the filesystem gets left at the altar once again. We should know by this time next year.

(对文件系统的操作看来这次也是一个比较关注的事宜——如果真的能够做到在跨平台之后无需改变负责I/O部分的代码的话，我想无论是对于Java EE 还是Java桌面应用乃至Java ME都是利好的消息。)

Experimentation

Whatever changes are made, it would be nice if they could be implemented in open source forks first, so we can see just how much or how little difference they really make. Toward this end, Sun's Peter Ahè has started the Kitchen Sink Project on java.net. The goal is to branch and fork the javac compiler repeatedly to test many different ideas like these. Blogging about pet features is one thing; actually producing running code is something else entirely.

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来源：http://tech.163.com/06/1214/08/329R7I3C00091537.html

作者：美国国家地理杂志           翻译编辑：网易探索 编译/卡迈拉

美国国家地理评选出的2006年度最具吸引力的十大新闻故事

1． 《犹大福音》揭秘：犹大不是叛徒，是英雄

新发现的《犹大福音》的残页

一本失踪了近1700年的《犹大福音》对于犹大和耶稣之间的关系提出了一种截然不同的观点，它不同于《马太福音》、《马可福音》、《约翰福音》等将犹大描绘成叛徒，新发现的福音认为犹大是应耶稣的要求才把他出卖的，并非是他本人的意愿。

2． 土耳其惊现用四肢走路的“爬行家族”，为人类的进化提供宝贵线索。

今年3月土耳其的科学家在当地的一处偏远地区发现了一户“爬行家族”，该家族里的三位姐妹和两位兄弟都是靠手脚在地面上爬行前进，而且说类似大猩猩叫声的原始语言。他们的父母已经60多岁，属于近亲结婚，生有19名子女，除了他们5个之外，其他兄弟姐妹都和正常人一样用双脚走路。科学家研究后发现他们存在严重的基因缺陷，所以无法直立行走，平时只能用四肢爬行走路，言行能力倒退100多万年。科学家称有关发现可能为人类在超过300万年前如何进化至用两脚步行提供珍贵的资料。

3． “鳄鱼猎人”史蒂夫·欧文被魟鱼背棘刺中胸部中毒身亡

“鳄鱼猎人”史蒂夫·欧文

著名的动物保护主义者，电视明星“鳄鱼猎人”史蒂夫-欧文( Steve Irwin ) 在今年9月4日在澳东北部海域录制一部水下纪录片时被一条魟鱼的背棘刺中胸部，中毒身亡，年仅44岁。

欧文1962年2月22日生于澳大利亚墨尔本，幼年随父母移居澳大利亚昆士兰州。他自小热爱野生动物，9岁时曾徒手捕到一条鳄鱼。1991年，他接管父亲留下的爬行动物园并将其更名为“澳大利亚动物园”。

1992年，欧文录制了他的第一部纪录片《鳄鱼猎人日记》，并通过《探索》有线电视频道在全球播出，欧文因此一举成名。他生前录制的《鳄鱼猎人日记》节目全球观众总数达2亿人。

4． 失踪1700多年《犹大福音》的传奇之旅

失踪1700多年的《犹大福音》手稿它本身的故事与它里面所描述犹大和耶稣之间的故事一样具有传奇色彩。

在这本手抄本里，故事中描绘了犹大不是我们先前所认为的叛徒，而是英雄，他是应耶稣要求才出卖了他。它被埋藏了数个世纪，在20世纪70年代后期人们在埃及发现了它，当时只是一堆残缺破损的草纸，它用古代埃及所使用的哥普特文字抄写，大约抄于公元3世纪到4世纪之间，从内容上看大约写于公元180年左右。在1980年，一次抢劫案中被人偷走被带出了埃及，后来在瑞士人们又找到了它，学者们想把它买下来做细致的研究，但当时手稿主人要价300万美元，但没人买的起，于是这份手稿在纽约州长岛花旗银行的保险箱躺了近二十年，直到前几年，才由瑞士的梅塞纳－马恩省斯古代艺术基金会取得，才最终被修复、重组、翻译后公布于众。最后，所有的书稿又被带回到了埃及，被存放在了柯普特博物馆里。

5．印尼发现“失落的世界”，雨林中发现上百新奇物种

罕见的金披凤树袋鼠在那里被发现，它被认为是世界上最漂亮的袋鼠,同时也是栖息在丛林地区的最为珍贵的有袋动物。

这是一种叫做密雀的鸟类，人们上一次见到这种稀有鸟类是在1939年。

科学家首次拍到了这种被他们叫做新几内亚“天堂迷失”鸟的图片。鸟类学家Berlepsch将它命名为“六线天堂鸟”，因其头部长有六根精美的羽毛。人们只在一个世纪前看到过一次这种鸟。

这只个头较小的蛙是科学家在岛上发现的20个蛙类新物种里的一种，大约只有14毫米长。

在南太平洋的岛屿丛林深处，探险家们发现了一座世外桃源，那里生活着许多不知名的袋鼠、鸟类、昆虫以及其他动物等等。

在新几内亚南太平洋的一座孤岛上，一个科学家小组在那里进行了15天的探险活动，发现了许多未曾见过的或者先前认为已经灭绝的物种。

6． 诺亚方舟在伊朗被发现？

今年7月，科学家在伊朗的厄尔布尔士山脉中发现了一块船形的巨型岩石，一些基督教考古学家们猜测它可能是传说中的诺亚方舟的遗骸。许多人对此都表示怀疑。一些圣经学者认为诺亚方舟应该在土耳其东部的阿拉拉特山脉附近，他们认为诺亚是在6000年前到10000年前建造了诺亚方舟。

 

7． 巨型兔子入侵英国村庄

 

德国埃伯斯瓦尔德市，一名兔子饲养员手提一只雄兔。专家认为那只村名发现的巨兔，可能就是饲养的兔子逃出去后野化的结果。

今年四月，英国某村庄发生了一件怪事，一只和狗一般大小的兔子突然闯入村子里的菜园，偷吃那里的蔬菜。这只兔子白天藏身洞穴，晚上就出来偷吃那里农作物，而且胃口特别大，神出鬼没，弄的整个村子鸡犬不宁，而且只有几位村名见过它，他们说这只兔子身形比一般兔子大的多，毛色呈黑色和棕色。气愤的村民布下了各种陷阱捕杀它，当地政府还把这件事列入了要务。

 

8．2000年前爱尔兰古尸赶时髦用发胶、修指甲

今年1月，考古学家发现，在爱尔兰沼泽地发现的两具铁器时代的古尸，其中一具古尸的头发用了发胶，可能是为了使自己看起来更高更优雅，他的身高只有1.57米。另外一具则修剪了指甲，站起来有1.98米高。他们大约生活在公元前392年到201年之间，使用的发胶由松树的树脂和蔬菜汁混合而成。两具古尸年龄大约在20多岁，可能是被谋杀。科学家猜测他们很可能是2300多年前的爱尔兰贵族。

 

9． 冥王星被赶出9大行星行列

今年8月，国际天文学联合会大会上冥王星被开除出了9大行星的行列，而被归入了“矮行星”。冥王星直径只有2300公里，比月球还要小，它所处的轨道在海王星之外，属于太阳系外围的柯伊伯带，这个区域一直是太阳系小行星和彗星诞生的地方。冥王星的出局也在国际上引发了很大争论。

太阳系新家谱：

一、行星：成员包括水星、金星、地球等8颗行星。定义：围绕太阳运转，自身引力足以克服其刚体力而使天体呈圆球状，并且能够清除其轨道附近其他物体的天体。

二、矮行星：成员包括冥王星和谷神星等。定义：与行星同样具有足够的质量，呈圆球状，但不能清除其轨道附近其他物体的天体。

三、太阳系小天体。定义：围绕太阳运转但不符合行星和矮行星条件的物体。

 

10．为穆斯林妇女特制的可遮盖全身的运动衣

 

一名穆斯林妇女穿着特制的可以遮盖全身的泳衣，使她不会违背《可兰经》上的守则。

在穆斯林的守则里，女子的穿着必须遮盖住全身，只可露出面孔、手、脚。多年来穆斯林女性一直在为寻找一件合适的运动衣而努力。现在，澳大利亚的一家名为Ahiida的公司采用一种很轻的织物设计出了一种可以覆盖全身的衣服，取名为Hijood，该公司还专门为穆斯林女性设计了一种可以遮盖全身的泳衣。同时，这些特制的运动衣也受到了那些不喜欢展示自己身体皮肤的人的欢迎。

冥王星和其最大的卫星的艺术图这具生活在铁器时代的古尸还修了指甲用发胶的爱尔兰古尸头部图像

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