添加删除.svn,cvs右键菜单的注册表 以及解锁问题

对于软件人士来说,常常需要删除某个源码文件夹下面所有cvs,.svn文件夹。

现在介绍一个网上流传的注册表方法:

删除CVS代码:delCVS.reg

Windows Registry Editor Version 5.00   
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteCVS] 
   @="Delete CVS Folders" 
[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteCVS\command]  
     @="cmd.exe /c \"TITLE Removing CVS Folders in %1 && COLOR 9A && FOR /r \"%1\" %%f IN (CVS) DO RD /s /q \"%%f\" \""  
将上面的代码保存为delCVS.reg 后双击此文件即可,可看到文件夹右键多出个Delete CVS Folders菜单.如图

6ebc7152e122acda8d5430ff

根据上面的代码,通过修改蓝色部分,你可以自己定制更多的右键菜单来删除不同的文件夹.

下面是删除svn文件夹的代码:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteSVN]
@="Delete SVN Folders"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Folder\shell\DeleteSVN\command]
@="cmd.exe /c \"TITLE Removing SVN Folders in %1 && COLOR 9A && FOR /r \"%1\" %%f IN (.svn) DO RD /s /q \"%%f\" \""

 

另外,常常遇到文件被锁,使用clean up也出错的情况,可以使用bat命令解决:

cd 到svn项目目录下,然后执行如下命令 
del lock /q/s 
就把锁删掉了。

Continue reading 添加删除.svn,cvs右键菜单的注册表 以及解锁问题

xml带冒号属性怎么获取

dom4j 的el.attributeValue是无法取到名空间类型的属性,简单点说就是带冒号的属性。

带冒号的属性是与名空间定义有关的,例如

<a xmlns="http://www.w3.org/xxx" xml:lang="en"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/xxx http://www.w3.org/xxx.xsd" >

这其中的蓝色部分就是特殊属性。

要取这样的属性在dom4j中应该这样做:

xmlns是名空间Element.getNamespaceURI()可以获得

xmlns:xsi   --> Element.getNamespaceForPrefix("xsi").getURI()

xsi:schemaLocation --> el.selectSingleNode("@xsi:schemaLocation").getText()

Continue reading xml带冒号属性怎么获取

maven 导致文件损坏的问题

1 :gzip格式打包时被损坏:

今天花了一天时间,找出一个原来运行得好好的程序无法运行的原因:maven打包时将包资源里的gzip格式文件搞坏了。结果发布到产品环境下的gzip资源总是不可用,我勒个去!maven你怎么不去屎啊!

2:编译时图片(主要是png图片)资源拷贝损坏:

写swing程序时,放在源代码文件夹内的图片资源在生成到target/classes/文件夹下时出现损坏。

出现异常:

sun.awt.image.PNGImageDecoder$PNGException: crc corruption

原来是是将资源编译了

解决办法:

pom里面设置资源不编译:(但是maven默认就是false,不知怎么回事。)

      <build>
		<resources>
		<resource>
	        <directory>src/main/resources</directory>
	        <filtering>false</filtering>
      	</resource>
      	</resources>
		<finalName>xxx</finalName>		
	</build>

记住要清空再编译就发现图片好了。

Continue reading maven 导致文件损坏的问题

it-e-01 four kinds of computers

Computers are electronic devices that can follow instructions to accept input, process that
input, and produce information. There are four types of computers: microcomputers, minicomputers,
mainframe computers, and supercomputers.
Microcomputers, also known as personal computers, are small computers that can fit on a desktop.
Portable microcomputers can fit in a briefcase or even in the palm of your hand. Microcomputers are
used in homes, schools, and industry. Today nearly every field uses microcomputers.
One type of microcomputer that is rapidly growing in popularity is the portable computer,
which can be easily carried around. There are four categories of portable computers.
Laptops: laptops, which weigh between 10 and 16 pounds, may be AC-powered, battery-powered,
or both. The AC-powered laptop weighs 12 to 16 pounds. The battery-powered laptop weighs 10 to 15
pounds, batteries included, and can be carried on a shoulder strap.
Notebook PCs: notebook personal computers weigh between 5 and 10 pounds and can fit
into most briefcases. It is especially valuable in locations where electrical connections are not
available. Notebook computers are the most popular portable computers today.
Subnotebooks: subnotebooks are for frequent flyers and life-on-the-road types.[1] Subnotebooks
users give up a full-size display screen and keyboard in exchange for less weight. Weighting between
2 and 6 pounds, these computer fit easily into a briefcase.
Personal Digital Assistants: much smaller than even the subnotebooks. Personal Digital
Assistants (PDAs) weigh from 1 to 4 pounds. The typical PDA combines pen input, writing
recognition, personal organizational tools, and communication capabilities in a very small
package.
Minicomputers, also knows as midrange computers, are desk-sized machines. [2]They fall into
between microcomputers and mainframes in their processing speeds and data-storing capacities.
Medium-size companies or departments of large companies typically use them for specific purposes.
For example, they might use them to do research or to monitor a particular manufacturing process.
Smaller-size companies typically use microcomputers for their general data processing needs, such as
accounting.
Mainframe computers are larger computers occupying specially wired, air-conditioned rooms
and capable of great processing speeds and data storage. They are used by large organizations
business, banks, universities, government agencies—to handle millions of transactions. For
example, insurance companies use mainframes to process information about millions of policyholders.
Supercomputers are special, high-capacity computers used by very large organizations principally
for research purposes. Among their uses are oil exploration and worldwide weather forecasting.
In general, a computer's type is determined by the following seven factors:

The type of CPU. Microcomputers use microprocessors. The larger computers tend to use
CPUs made up of separate, high-speed, sophisticated components.
The amount of main memory the CPU can use. A computer equipped with a large
amount of main memory can support more sophisticated programs and can even hold several
different programs in memory at the same time.
The capacity of the storage devices. The larger computers systems tend to be equipped
with higher capacity storage devices.
The speed of the output devices. [3]The speed of microcomputer output devices tends to be
rated in terms of the number of characters per second (cps) that can be printed usually in tens
and hundreds of cps. Larger computers' output devices are faster and are usually rated at speeds
of hundreds or thousands of lines that can be printed per minute.
The processing speed in millions of instructions per second (mips). The term instruction
is used here to describe a basic task the software asks the computer to perform while also
identifying the data to be affected. The processing speed of the smaller computers ranges from 7
to 40 mips. The speed of large computers can be 30 to 150 mips or more, and supercomputers
can process more than 200 mips. In other words, a mainframe computer can process your data a
great deal faster than a microcomputer can.
The number of users that can access the computer at one time. Most small computers
can support only a single user, some can support as many as two or three at a time. Large
computers can support hundreds of users simultaneously.
The cost of the computer system. Business systems can cost as little as $500 (for a
microcomputer) or as much as $10 million (for a mainframe) and much more for supercomputer.

Continue reading it-e-01 four kinds of computers

it-e-02 web harvesting

As the amount of information on the Web grows, that information becomes ever harder to
keep track of and use. Search engines are a big help, but they can do only part of the work, and
they are hard-pressed to keep up with daily changes.
Consider that even when you use a search engine to locate data, you still have to do the
following tasks to capture the information you need: scan the content until you find the
information, mark the information (usually by highlighting with a mouse), switch to another
application ( such as a spreadsheet, database or word processor), paste the information into that
application.

A better solution, especially for companies that are aiming to exploit a broad swath of data
about markets or competitors, lies with Web harvesting tools.
Web harvesting software automatically extracts information from the Web and picks up
where search engines leave off, doing the work the search engine can't. Extraction tools automate
the reading, copying and pasting necessary to collect information for analysis, and they have
proved useful for pulling together information on competitors, prices and financial data or all
types.
There are three ways we can extract more useful information from the Web.
The first technique, Web content harvesting, is concerned directly with the specific content
of documents or their descriptions, such as HTML files, images or e-mail messages. Since most
text documents are relatively unstructured (at least as far as machine interpretation is concerned),
one common approach is to exploit what's already known about the general structure of
documents and map this to some data model.
The other approach to Web content harvesting involves trying to improve on the content
searches that tools like search engines perform. This type of content harvesting goes beyond
keyword extraction and the production of simple statistics relating to words and phrases in
documents.
Another technique, Web structure harvesting, takes advantage of the fact that Web pages
can reveal more information than just their obvious content. Links from other sources that point
to a particular Web page indicate the popularity of that page, while links within a Web page that
point to other resources may indicate the richness or variety of topics covered in that page. This
is like analyzing bibliographical citations— paper that's often cited in bibliographies and other
paper is usually considered to be important.
The third technique, Web usage harvesting, uses data recorded by Web servers about user
interactions to help understand user behavior and evaluate the effectiveness of the Web structure.
General access—pattern tracking analyzes Web logs to understand access patterns and
trends in order to identify structural issues and resource groupings.
Customized usage tracking analyzes individual trends so that Web sites can be personalized
to specific users. Over time, based on access patterns, a site can be dynamically customized for a
user in terms of the information displayed , the depth of the site structure and the format of the
resource presented.

Continue reading it-e-02 web harvesting

读The Definitive ANTLR Reference

没看的很明白,摸出来的。

lexer?parser?tree?token?

token以大写字母开头,对应目标语言的静态字段。

rule以小写字母开头对应目标语言的实例方法。

token里面的连接表现和rule里面的连接表现是不一样的。

TOKEN:

'h' 'i' //匹配hi

rule:

'h' 'i'//匹配h i,不匹配hi[中间有空格的区别]

子rule用()包含

action用{}包含,使用目标语言写

ANTLR中表示字符要用“’”单引号括起来,用‘(’ ‘)’来表示括号字符

channel:

解析的token放在不同的channel,由你来设定。

token序号是整体排序的

The token buffer preserves the relative token order regardless of the token channel numbers.

skip()小心用。

WS : (' ' |'\t' |'\r' |'\n' )+ {skip();$channel=HIDDEN;} ; //这样将匹配丢到hidden chennel可行,那么不行需要再写其他的rule时总是要写WS匹配。例: WS?'hello' WS+ 'how' WS+ 'are' WS+ 'you' -->'hello' 'how' 'are' 'you'.

Method skip( ) in an embedded lexer rule action forces the lexer to throw
out the token and look for another.运行结果似乎是视而不见【抛弃】。

fragment

如果一个token被另外的token使用,则被使用的token需要加fragment标记。

如果加了fragment,则此token不要在rule里面直接引用[如果引用了会达不到预期结果],而应该在其他的token里面引用。

对于没有加frgament的token又有个原则,它不能与其他的token有交集。即不能一个输入既可以匹配token1又可以匹配token2.

使用antlrworks时,如果出现警告,尽量消除它。尽量列举所有的情况而不要使用多个* ?来匹配。

错误解读:

line 12:15 no viable alternative at input 'xxx'

12行15字碰到没有定义的输入xxx【定义中没有列举这样的输入情况】

局部规则可能影响整个规则,特别对于+ *之类的泛匹配例如('a'..'z' | 'A'..'Z')+

暂且放下:

遇到的困难:

1:对于无引号token不知如何识别,如果使用

TOKEN=CHAR+

rule = TOKEN+

则可以匹配所有,造成整个语法混乱

2:对于递归语法不知如何识别,例如

[[...] [...]] 和 ((...) (...))

Continue reading 读The Definitive ANTLR Reference

it-e-03 Computer hardware

Computer hardware has four parts: the central processing unit (CPU) and memory, storage
hardware, input hardware, and output hardware.
The part of the computer that runs the program is known as the processor or central processing
unit (CPU). In a microcomputer, the CPU is on a single electronic component, the microprocessor
chip, within the system unit or system cabinet. The CPU itself has two parts: the control unit and
the arithmetic-logic unit. In a microcomputer, these are both on the microcomputer chip.
The Control Unit The control unit tells the rest of the computer system how to carry out a
program's instructions. It directs the movement of electronic signals between memory and the
arithmetic-logic unit. It also directs these control signals between the CPU and input and output
devices.
The Arithmetic-Logic Unit The arithmetic-logic unit, usually called the ALU, performs
two types of operations—arithmetic and logical. Arithmetic operations are, as you might expect,
the fundamental math operations: addition, subtraction, multiplication, and division. Logical
operations consist of comparisons. That is , two pieces of data are compared to see whether one is
equal to, less than, or greater than the other.
Memory Memory is also known as primary storage, internal storage, it temporarily holds
data, program instructions, and information. One of the most important facts to know about
memory is that part of its content is held only temporarily. In other words, it is stored only as
long as the computer is turned on. When you turn the machine off, the content immediately
vanish. The stored contents in memory are volatile and can vanish very quickly.
Storage Hardware [1]The purpose of storage hardware is to provide a means of storing
computer instructions and data in a form that is relatively permanent, that is, the data is not lost
when the power is turned off—and easy to retrieve when needed for processing.There are four
kinds of storage hardware: floppy disks, hard disks,optical disk,andmagnetic tape.
Floppy Disks Floppy disks are also called diskettes, flexible disks, floppies, or simply

disks. The plastic disk inside the diskette cover is flexible, not rigid. They are flat, circular pieces
of mylar plastic that rotate within a jacket. Data and programs are stored as electromagnetic
charges on a metal oxide film coating the mylar plastic.
Hard Disks Hard disks consist of metallic rather than plastic platters. They are tightly
sealed to prevent any foreign matter from getting inside. Hard disks are extremely sensitive
instruments. The read-write head rides on a cushion of air about 0.000001 inch thick. It is so thin
that a smoke particle, fingerprint, dust, or human hair could cause what is known as a head crash.
A head crash happens when the surface of the read-write head or particles on its surface contact
the magnetic disk surface. A head crash is a disaster for a hard disk. It means that some or all of
the data on the disk is destroyed. Hard disks are assembled under sterile conditions and sealed
from impurities within their permanent containers.
Optical Disks Optical disks are used for storing great quantities of data. An optical disk can
hold 650 megabytes of data—the equivalent of hundreds of floppy disks. Moreover, an optical disk
makes an immense amount of information available on a microcomputer. In optical-disk technology,
a laser beamalters the surface of a plastic or metallic disk to represent data. To read the data, a laser
scans these areas and sends the data to a computer chip for conversion.
Magnetic Tape Magnetic tape is an effective way of making a backup, or duplicate, copy of
your programs and data. We mentioned the alarming consequences that can happen if a hard disk
suffers a head crash. You will lose some or all of your data or programs. Of course, you can always
make copies of your hard-disk files on floppy disks. However, this can be time-consuming and may
require many floppy disks. Magnetic tape is sequential access storage and can solve the problem
mentioned above.
Input Hardware Input devices take data and programs people can read or understand and
convert them to a form the computer can process. This is the machine-readable electronic signals
of 0s and 1s. Input hardware is of two kinds: keyboard entry and direct entry.
Keyboard Entry Data is input to the computer through a keyboard that looks like a
typewriter keyboard but has additional keys. In this method, the user typically reads from an
original document called the source document. The user enters that document by typing on the
keyboard.
Direct Entry :Data is made into machine-readable form as it is entered into the computer,
no keyboard is used. Direct entry devices may be categorized into three areas: pointing devices
(for example, mouse, touch screen, light pen, digitizer are all pointing devices), scanning devices
(for example, image scanner, fax machine, bar-code reader are all scanning devices), and
voice-input devices.
Output Hardware Output devices convert machine-readable information into people-readable
form. Common output devices are monitors, printers, plotters, and voice output.
Monitors Monitors are also called display screen or video display terminals. Most monitors that
sit on desks are built in the same way as television sets, these are called cathode-ray tubes. Another type
of monitor is flat-panel display, including liquid-crystal display (LCD), electroluminescent (EL) display

and gas-plasma display. An LCD does not emit light of its own. Rather, it consists of crystal molecules.
[2]An electric field causes the molecules to line up in a way that alters their optical properties.
Unfortunately, many LCDs are difficult to read in sunlight or other strong light. A gas-plasma display is
the best type of flat screen. Like a neon light bulb, the plasma display uses a gas that emits light in the
presence of an electric current.
Printers There are four popular kinds of printers: dot-matrix, laser, ink-jet, and thermal.
Dot-Matrix Printer Dot-matrix printers can produce a page of text in less than 10 seconds
and are highly reliable. They form characters or images using a series of small pins on a print
head. The pins strike an inked ribbon and create an image on paper. Printers are available with
print heads of 9, 18, or 24 pins. One disadvantage of this type of printer is noise.
Laser Printer The laser printer creates dotlike images on a drum, using a laser beam light
source. [3]The characters are treated with a magnetically charged inklike toner and then are
transferred from drum to paper. A heat process is used to make the characters adhere. The laser
printer produces images with excellent letter and graphics quality.
Ink-Jet Printer An ink-jet printer sprays small droplets of ink at high speed onto the
surface of the paper. This process not only produces a letter-quality image but also permits
printing to be done in a variety of colors.
Thermal Printer A thermal printer uses heat elements to produce images on heat-sensitive
paper. Color thermal printers are not as popular because of their cost and the requirement of
specifically treated paper. They are a more special use printer that produces near photographic
output. They are widely used in professional art and design work where very high quality color is
essential.
Plotters Plotters are special-purpose output devices for producing bar charts, maps, architectural
drawings, and even three-dimensional illustrations. Plotters can produce high-quality multicolor
documents and also documents that are larger in size than most printers can handle. There are four types
of plotters: pen, ink-jet, electrostatic, and direct imaging.
Voice-Output Devices Voice-output devices make sounds that resemble human speech but
actually are pre-recorded vocalized sounds. Voice output is used as a reinforcement tool for
learning, such as to help students study a foreign language. It is used in many supermarkets at the
checkout counter to confirm purchases. Of course, one of the most powerful capabilities is to
assist the physically challenged.

Continue reading it-e-03 Computer hardware

skype4java :

skype4java 地址:

http://skype.sourceforge.jp/index.php?Skype%20API%20For%20Java%20%28English%29

使用jni封装skype com+接口

但其

Win32Connector::protected void initializeImpl() 方法有些问题,其意图是如果没又找到skype库就从包里面解压缩skype.dll到临时文件夹下,但是我不知道为什么作者要用zip遍历,而不是使用类加载器获得资源来解压缩。

我做的修改:

try {
            System.loadLibrary("skype");
        } catch(Throwable e) {
            try {
                if(!ConnectorUtils.checkLibraryInPath(LIBFILENAME)) {
                    String dllPath;
                    String tmpDir = System.getProperty("java.io.tmpdir");
                    if(!tmpDir.endsWith("" + File.separatorChar)) {
                        tmpDir = tmpDir + File.separatorChar;
                    }
                    dllPath = tmpDir + LIBFILENAME;
                    File dll = new File(dllPath);
                    if(!dll.exists()) {
extractDll(dll);
                        if(!dll.exists()) {
                            throw new RuntimeException("can't load " + dllPath);
                        }
                    }
                    System.load(dllPath);
                }
            } catch(Exception e1) {
                throw new RuntimeException(e1);
            }
        }

private void extractDll(File destFile) {
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        InputStream input = loader.getResourceAsStream(LIBFILENAME);
        FileOutputStream output = null;
        try {
            output = new FileOutputStream(destFile);
            byte[] buffer = new byte[1024 * 4];
            long count = 0;
            int n = 0;
            while(-1 != (n = input.read(buffer))) {
                output.write(buffer, 0, n);
                count += n;
            }
        } catch(Exception e) {
            throw new RuntimeException(e);
        } finally {
            try {
                if(null != input) {
                    input.close();
                }
            } catch(IOException e) {
            }
            try {
                if(null != output) {
                    output.close();
                }
            } catch(IOException e) {
            }
        }
    }

需要

winp.jar 检查是否running

swt.jar 借用OS基础功能

Continue reading skype4java :

[转]未来五年可能流行的十大网络技术

10。IP语音

出于成本和便捷因素的考虑,目前很多公司和消费者都已经开始使用VoIP的电话服务。根据SearchVoIP网站在2007年6月份进行的一项调查,纯IP PBX系统在2007年第一季度的销售比上一季度上涨了76%。

越来越多的公司期待加入VoIP阵营,让VoIP设备作为对传统固定电话的补充或者干脆替代后者。因为VoIP运行在TCP/IP网络,所以IT管理员们在很多情况下都会负责VoIP的部署和维护。

9。网络安全技术

精明的IT专家已经在近几年掌握了大量的安全技能,但未来新的安全挑战和新的安全机制会不断涌现。诸如VoIP和移动计算这些应用都带来了新的安全问题和挑战,而且身份认证方式也从单一的基于密码的模式转变为更加多元化的新模式,生物学的应用将会在未来越来越凸显其重要性。

安全威胁也越来越普及,当初只是一些少年黑客为了乐趣而破解网站,现在的网上暴徒却已经开始瞄准公司的商业秘密以及虚拟资产,这些人对网络的攻击已经威胁到了国家整体的虚拟架构,所以我们的安全技术必须随时更新。

8。IPv6

作为下一代Internet协议,IPv6的普及似乎并不像人们此前所预想的那么快速,很大程度上是因为诸如NAT这样的技术的应用能够减缓IP地址的消耗。

然而Internet上的主机数量不断稳定增长,最终我们必然需要扩展更大的地址空间。除了巨大的地址容量之外,IPv6还通过IPsec这一基础的协议组件提供更好的安全性能。目前像Windows Vista、Windows Server 2008、Mac OS X 10.3以及其他最新的操作系统都已经默认支持IPv6,这些操作系统的支持可以看作IPv6已经具备了腾飞的基础。

IPv6的CIDR使用了完全不同的地址符号,采用16进制代码代替了我们所熟悉的4个八位的10进制IPv4代码。对于IT管理员来讲,学习新的只是有些困难,但在转变全面来临之前,我们必须掌握IPv6技术。

7。虚拟化

虚拟化已经出现一段时间了,但目前它才真正开始成熟。微软即将推出的Windows Server 2008服务器操作系统将会包含其大力研发的Windows hypervisor技术(Viridian);而VMWare也提供了免费的VMWare Server,红帽和SuSE也计划在下一版本的服务器产品中包含Xen hypervisor技术。我们可以判定,虚拟机的概念将会在未来几年上升到一个全新的阶段。

管理基于虚拟机的网络环境需要很高的技术修养,但有越来越多的公司开始组建虚拟化技术的服务器,以此来节省硬件支出,这将成为一个必然的趋势。

6。SaaS(软件即服务)

代表了下一代以太网的Web 2.0采用了SaaS(Software as a Service)模式,它通过互联网提供软件服务,而不需要在每个用户的电脑里单独安装应用程序。一些IT专家已经警告称SaaS将会完全取代企业内IT 管理员的工作,但更广为接受的说法则称SaaS将会把IT管理员从繁重的配置和维护工作中解脱出来,而将精力更加集中地投入到对全局的计划以及融合上。

事实上即使SaaS没有出现,IT管理员的职位也会发生变化,会有更多的职位专注于提供应用程序的板块,而不是仅仅关注公司内部的IT部门。在这种情况下,IT员工应该学习一些服务提供和多客户共享架构的知识,这样才能顺应着环境的变化而走在前头。

5。支持移动用户

智能手机、PDA、UMpc以及其他便携式设备已经大量应用,并且在未来会越来越广泛。雇员将会通过手机接收公司的电子邮件,而且有些时候还会通过使用终端服务软件接入公司的局域网。

企业内的IT员工需要多学习支持移动用户的技术,包括设置邮件服务器以及保障设备安全性等。

4。远程用户支持

目前的趋势已经很明显,更多的雇员将会在公司外办公:每周至少会有几天时间,人们在路上使用笔记本电脑,或者在家里使用私人电脑,并且这些员工需要远程接入公司的局域网。所以IT管理员需要对这些远程用户提供支持,并且保证内部网络的安全。

学习与VPN技术相关的不同的技能十分重要,比如SSL VPN技术就十分有用。我们可以利用健康监测以及隔离远程客户端阻止那些未达到安全要求最低准则的电脑接入局域网,以免其对网络产生危害。

3。无线技术

企业级的无线网络目前仍然处于未成熟阶段,很多公司多不太情愿安装无线局域网,安装它只是因为无线局域网能够为雇员以及其他来访者的笔记本电脑接入网络提供最简便的方式,但是仍然有很多组织对其报有戒心,尤其是无线网络的安全性能。

未来一定会出现更快速也更安全的无线技术。你需要了解802.11n,这一新的标准目前还处于开发阶段,但已经确定会在2008年底正式公布。 802.11n能够提供典型的74Mbps吞吐量,最高可达248Mbps,另外它的有效半径也远高于目前的802.11a/b/g标准,可以达到70 米。

2。混合网络

要么全部都是Windows网络,要么全部都是UNIX网络的时代已经过去了,网络在未来会变得更加混合,而不是更加纯粹。当像Ubuntu这些对终端用户十分友好的新版本Linux出现之后,未来我们会看到更多的组织会为其特定用户的桌面电脑配置这些系统。

然而出于应用软件的原因或者个人喜好,其他用户将会继续使用Windows,另外还有很多用户在混合着使用苹果电脑,尤其是在图形处理领域。 仅仅精通一种平台在今后是不会成为IT专家的;你需要周游于不同的操作系统之间,解决各种问题。

1。统一通信
随着VoIP越来越流行,统一通信的概念——不同通信技术的汇合,诸如电子邮件、语音消息、文本短信以及传真等的汇合—— 将会成为下一波技术浪潮的热点。用户今后可以从一个单独的界面上接入所有的通信设备,比如从各种不同的设备上接入电子邮箱,这些设备可以是台式电脑、笔记本电脑、智能手机或者PDA、甚至传统电话。

技术的融合使得网络变得更加复杂,而IT管理员需要提升自身管理融合网络的技能,以面对未来的技术挑战。

 

PS:

802.11b 2.4g频段 最大11m/s 一般6.5m/s。
wi-fi与802.11x不是一个概念,虽然有关联。

Continue reading [转]未来五年可能流行的十大网络技术

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