Rank 1:

       SIGMOD: ACM SIGMOD Conf on Management of Data
       PODS: ACM SIGMOD Conf on Principles of DB Systems
       VLDB: Very Large Data Bases
       ICDE: Intl Conf on Data Engineering

       CIKM: Intl. Conf on Information and Knowledge Management
       ICDT: Intl Conf on Database Theory

Rank 2:

SSD: Intl Symp on Large Spatial Databases
DEXA: Database and Expert System Applications
FODO: Intl Conf on Foundation on Data Organization
EDBT: Extending DB Technology
DOOD: Deductive and Object-Oriented Databases
DASFAA: Database Systems for Advanced Applications
SSDBM: Intl Conf on Scientific and Statistical DB Mgmt
CoopIS - Conference on Cooperative Information Systems
ER - Intl Conf on Conceptual Modeling (ER)

參考 http://www3.ntu.edu.sg/home/assourav/crank.htm

     摘要: That’s why I don’t want to hear people’s ideas.
I’m not interested until I see their execution.  閱讀全文      摘要: 這兩天在學(xué)習(xí)python，主要參考簡(jiǎn)明教程http://www.swaroopch.com/byteofpython/ ， 入門(mén)很不錯(cuò)，有興趣推薦參考。
在16章中，作者建議讀者寫(xiě)一個(gè)地址簿程序，還記得寫(xiě)它都是在大一學(xué)c語(yǔ)言的年代了，不過(guò)下午還是抽出了一點(diǎn)時(shí)間來(lái)寫(xiě)這個(gè)程序，寫(xiě)了兩個(gè)版本，一個(gè)是使用python 字典來(lái)存儲(chǔ)名字和地址，另一個(gè)版本則使用python的面向?qū)ο筇匦裕瑏?lái)鏈?zhǔn)酱鎯?chǔ)聯(lián)系人對(duì)象。  閱讀全文      摘要: 據(jù)說(shuō)最近psp最近要升值了～無(wú)論是因?yàn)槠平獾脑蜻€是什么，但總之估計(jì)sony還是很難想到，當(dāng)然我們也很值得慶幸的是這幫hack的大牛已然將kvm，python stackless等移植到了psp平臺(tái)，強(qiáng)大的ppc支持，可足以媲美幾年前的personal computer，這一點(diǎn)毋庸置疑，更不用去與手機(jī)平臺(tái)相對(duì)比了。  閱讀全文      摘要: org.eclipse.jface.viewers.TreeViewer

的繼承關(guān)系是  閱讀全文 目前 ext已經(jīng)全面升級(jí)了主站，而且也release2.1版本，并新增了一些例子。
最近發(fā)布的Firefox3 beta 5版本，個(gè)人認(rèn)為還是比較不錯(cuò)，運(yùn)行JS的也更快、上網(wǎng)速度也快了很多。
但經(jīng)原來(lái)做的一些js程序測(cè)試，ext2.0版本運(yùn)行在FF3Beta5上還存在一些顯示問(wèn)題。

     摘要: 昨天寫(xiě)了個(gè)關(guān)于圖庫(kù)的總結(jié)mail 在這貼下，以供參考，當(dāng)然望不吝賜教  閱讀全文      摘要: 前兩天寫(xiě)了一個(gè)處理邏輯表達(dá)式的小程序，可以用來(lái)處理專(zhuān)家系統(tǒng)實(shí)事等邏輯關(guān)系表達(dá)式。  閱讀全文      摘要: EasyMock 是一套通過(guò)簡(jiǎn)單的方法對(duì)于指定的接口或類(lèi)生成 Mock 對(duì)象的類(lèi)庫(kù)，它能利用對(duì)接口或類(lèi)的模擬來(lái)輔助單元測(cè)試。本文將對(duì) EasyMock 的功能和原理進(jìn)行介紹，并通過(guò)示例來(lái)說(shuō)明如何使用 EasyMock 進(jìn)行單元測(cè)試。   閱讀全文      摘要: Craigslist的網(wǎng)站上沒(méi)有圖片，只有密密麻麻的文字，標(biāo)著各種生活信息，是個(gè)巨大無(wú)比的網(wǎng)上分類(lèi)廣告加BBS的組合...  閱讀全文      摘要: Trie樹(shù)是一棵度 m ≥ 2 的樹(shù)，它的每一層分支不是靠整個(gè)關(guān)鍵碼的值來(lái)確定，而是由關(guān)鍵碼的一個(gè)分量來(lái)確定。  閱讀全文      摘要: For myself learning.
Personal Mastery  閱讀全文      摘要: Have you read Jess In Action by Earnest J. Freedman-Hill? It's one of the better books out there on rule engines, though it does require some experience to get the most out of the book.
A variation on the bookstore could be recommendation engine. That would provide an opportunity to use a rule engine for direct matching on category/subcategory and aggregations.  閱讀全文      摘要: IBM Dump Analyzer for Java是來(lái)分析虛擬機(jī)穩(wěn)定性的一種可擴(kuò)展框架。對(duì)Java虛擬機(jī)生成的產(chǎn)物進(jìn)行自動(dòng)診斷。  閱讀全文      摘要: 實(shí)在忍受不了sun的做事風(fēng)格和它的開(kāi)發(fā)工具了，nb的beta6一踏糊涂一堆bug，唉~想著就想起來(lái)sun中國(guó)弄個(gè)nb插件的比賽不僅過(guò)程糟糕，獲獎(jiǎng)了居然還不兌現(xiàn)承諾，到現(xiàn)在也杳無(wú)音信，估計(jì)是證書(shū)也不想發(fā)了，真是讓大家對(duì)它越發(fā)感到?jīng)]有信心~~~~~~~~~不提這個(gè)了，還是講講Europa 和 myeclipse， 最近在寫(xiě)一個(gè)基于規(guī)則的引擎，用的Europa 和myeclipse6 感覺(jué)非常舒服，myeclipse的功能也大大加強(qiáng)了比如改進(jìn)了javaEE5 提高了EJB3開(kāi)發(fā)效率可以支持從數(shù)據(jù)模型到bean的轉(zhuǎn)換，java的持久化程度及其Spring-JPA的高度集成。開(kāi)發(fā)ajax的朋友可以發(fā)現(xiàn) myeclipse對(duì)ajax的開(kāi)發(fā)和測(cè)試做的也非常好，尤其是對(duì)js的調(diào)試。Web開(kāi)發(fā)的另一個(gè)特點(diǎn)是支持RAD web。nb原來(lái)喊的一項(xiàng)特色是集成了matisse，在myeclipse目前也集成了它而且對(duì)于可視化swing開(kāi)發(fā)非常方便，當(dāng)然你也可以自己按照，不直接更新。
myeclipse中集成的derby和tomcat也大大加速了服務(wù)器的連接和部署，調(diào)試等。至于db視圖個(gè)人使用oracle  閱讀全文      摘要: Given a picture composed entirely of horizontal and vertical line segments, calculate the minimum number of times you must lift your pen to trace every line segment in the picture exactly n times.
Each line segment will be of the form " " (quotes for clarity), representing a segment from (x1,y1) to (x2,y2). Segments may cross each other. Segments may also overlap, in which case you should count the overlapping region as appearing in the drawing only once. For example, say t  閱讀全文

posted @ 2007-10-30 21:36 wqwqwqwqwq 閱讀(1190) | 評(píng)論 (0) | 編輯 收藏

Lottery Again

     摘要: In most states, gamblers can choose from a wide variety of different lottery games. The rules of a lottery are defined by two integers (choices and blanks) and two boolean variables (sorted and unique). choices represents the highest valid number that you may use on your lottery ticket. (All integers between 1 and choices, inclusive, are valid and can appear on your ticket.) blanks represents the number of spots on your ticket where numbers can be written.  閱讀全文

posted @ 2007-10-24 21:20 wqwqwqwqwq 閱讀(1208) | 評(píng)論 (1) | 編輯 收藏

A Q of Encrypting String

     摘要:
Let's say you have a binary string such as the following:
011100011
One way to encrypt this string is to add to each digit the sum of its adjacent digits. For example, the above string would become:
123210122  閱讀全文

posted @ 2007-10-23 13:34 wqwqwqwqwq 閱讀(1057) | 評(píng)論 (1) | 編輯 收藏

Maze Problem

     摘要: People enjoy mazes, but they also get them dirty. Arrows, graffiti, and chewing gum are just a few of the souvenirs people leave on the walls. You, the maze keeper, are assigned to whiten the maze walls. Each face of the wall requires one liter of paint, but you are only required to paint visible faces. You are given a map of the maze, and you must determine the amount of paint needed for the job.  閱讀全文

posted @ 2007-10-21 21:28 wqwqwqwqwq 閱讀(1462) | 評(píng)論 (1) | 編輯 收藏

TopCoder_2

     摘要: In written languages, some symbols may appear more often than others. Expected frequency tables have been defined for many languages. For each symbol in a language, a frequency table will contain its expected percentage in a typical passage written in that language. For example, if the symbol "a" has an expected percentage of 5, then 5% of the letters in a typical passage will be "a". If a passage contains 350 letters, then 'a' has an expected count of 17.5 for that passage (17.5 = 350 * 5%). Pl  閱讀全文

posted @ 2007-10-21 20:14 wqwqwqwqwq 閱讀(920) | 評(píng)論 (1) | 編輯 收藏

TopCoder_1

     摘要: A speed radar is installed in a highway zone where the maximum speed limit is maxLimit mph, and the minimum speed limit is minLimit mph.  閱讀全文

posted @ 2007-10-20 13:25 wqwqwqwqwq 閱讀(1265) | 評(píng)論 (1) | 編輯 收藏

Struts Review

     摘要: 好長(zhǎng)時(shí)間沒(méi)寫(xiě)程序了感覺(jué)，忘了很多東西，呵呵，今天打開(kāi)Eclipse寫(xiě)了一個(gè)Struts的小應(yīng)用，也回顧了一遍它的主要內(nèi)容，這篇隨筆就把整理的一些東西貼出來(lái)吧。  閱讀全文

posted @ 2007-10-07 16:55 wqwqwqwqwq 閱讀(1027) | 評(píng)論 (0) | 編輯 收藏

拐點(diǎn)提取法在曲線擬合中的簡(jiǎn)單應(yīng)用

     摘要: 本程序?yàn)閮?yōu)化，比較好的方法是，進(jìn)行曲線積分，算誤差比進(jìn)行方程約束，由于時(shí)間比較少，稍候會(huì)給出優(yōu)化程序。  閱讀全文

posted @ 2007-08-14 17:27 wqwqwqwqwq 閱讀(1007) | 評(píng)論 (0) | 編輯 收藏

Stack Simple implement

     摘要: A simple implement of own stack  閱讀全文

posted @ 2007-08-03 18:14 wqwqwqwqwq 閱讀(1000) | 評(píng)論 (0) | 編輯 收藏

To find a max segment in a array which includes negative and positive no.

     摘要: To find a max segment in a array which includes negative and positive no.There r several methods to solve this question.  閱讀全文

posted @ 2007-07-31 12:45 wqwqwqwqwq 閱讀(849) | 評(píng)論 (0) | 編輯 收藏

隨感

     摘要: 今天很早的來(lái)到公司，首先查收了一下郵箱，發(fā)現(xiàn)5封新郵件，仔細(xì)的看了下都是關(guān)于我前天申請(qǐng)一個(gè)IBM USA那邊的一個(gè)DB訪問(wèn)權(quán)限的郵件。  閱讀全文

posted @ 2007-07-27 08:55 wqwqwqwqwq 閱讀(300) | 評(píng)論 (2) | 編輯 收藏

@hotjava Smallworld&&PMI

     摘要: Sun has just announced the winners of netbeans plugin competition  閱讀全文

posted @ 2007-07-21 23:34 wqwqwqwqwq 閱讀(1141) | 評(píng)論 (0) | 編輯 收藏

PMI

     摘要: PMI(Performance MonitoringInfrastructure)   閱讀全文

posted @ 2007-07-13 17:32 wqwqwqwqwq 閱讀(1188) | 評(píng)論 (2) | 編輯 收藏

Sundries to && of myself

there r so many sundries during these days and almost every point is focussing on papers\projects\ ...\recommending data for my next master degree, but my thought just is in a mess, i cannot describe the stage && status except paying more attention,well,just feeling time is out of my hand.the only thing I am looking forward is the result of nb plugin competition and i will send the request and willing letter to the professors later but then.I m believing that though  have lost the opportunity of my target ~~God, it's so pity for a sudden change,at the same time, I stood with everything.I have got another time now and have prepared all the condition for the coming applying.thx in advance for my friends, because u have give a stage and some suporting.especially to stand^-^.TracyYan now has just rushing in && strangely,I find~~~~after six years,why not then, I have also no answers, may be pretty but not really for the feeling,~~~~~.
Yestoday I have collected some data about computer science department professors of pku, bless.
benny is a so kind person though he(she is a judge, but i really want to say,actually not to him.here the only puzzlement is why now after a month asking the method how to use the tool and why dont know the document which has contains all the info he want to know, I know, really, each guy is busy, busy with one's sundries,so many! Symptom.

posted @ 2007-07-11 22:19 wqwqwqwqwq 閱讀(529) | 評(píng)論 (0) | 編輯 收藏

JFx~~~~builder

     摘要: 首先說(shuō)點(diǎn)別的:),今天google adsense給我回信關(guān)于blog頭搜索不好用的原因是嵌在了里。我評(píng)論的前兩條是表?yè)P(yáng)google...  閱讀全文

posted @ 2007-06-02 23:16 wqwqwqwqwq 閱讀(1522) | 評(píng)論 (8) | 編輯 收藏

焦點(diǎn)關(guān)注

     摘要: 好長(zhǎng)時(shí)間沒(méi)寫(xiě)隨筆了^^，主要是因?yàn)檫@幾天很忙,ibm的、學(xué)校的、還有sun的插件大賽，但是這段時(shí)間自己確一直在學(xué)習(xí)，在繼續(xù)關(guān)注技術(shù)的進(jìn)展，隨著這篇關(guān)注焦點(diǎn)，在之后的幾天里，我會(huì)繼續(xù)寫(xiě)一些，IBM SOA、SOAP、RBD、EGL還有我們HotJava的 SmallWorld等內(nèi)容。
JavaFX當(dāng)前是備受SUN推崇和重點(diǎn)推廣的項(xiàng)目之一，也是Java技術(shù)繼續(xù)演化的內(nèi)容之一。  閱讀全文

posted @ 2007-05-31 11:03 wqwqwqwqwq 閱讀(1224) | 評(píng)論 (0) | 編輯 收藏

JNDI~基礎(chǔ)

     摘要: 今天瀏覽網(wǎng)頁(yè)，看見(jiàn)篇寫(xiě)JNDI比較基礎(chǔ)，也比較詳細(xì)的文章，又自己整理了一下，post到新手區(qū)了，。。。。：）JNDI是java訪問(wèn)名字和目錄服務(wù)的接口，與JDBC一樣，它僅僅只定義了一套服務(wù)接口，實(shí)現(xiàn)由具體廠商提供。作為j2ee核心組件之一，它為應(yīng)用程序查找其他程序組件和資源提供了統(tǒng)一的接口，其中最常見(jiàn)的用途就是數(shù)據(jù)源的配置、EJB名字查找、JMS相關(guān)配置等。JNDI的架構(gòu)如下圖。在JDK1.3中...  閱讀全文

posted @ 2007-05-14 23:33 wqwqwqwqwq 閱讀(820) | 評(píng)論 (0) | 編輯 收藏

ITM

     摘要: 開(kāi)篇，哈哈哈，我喜歡這句話(huà)“NO MONEY ONLY WORK DADADI”。
ITM provides out of box uses to quickly deploy and active the app with the best ibm practice.admins can define the user's views,threshold and so on.Tivoli Enterprise Monitoring Agents are available for monitoring different types of platforms and applications, including mainframes,middleware,distributed,and database...  閱讀全文

posted @ 2007-05-11 23:00 wqwqwqwqwq 閱讀(960) | 評(píng)論 (0) | 編輯 收藏

Little for ITM && CLI

     摘要: CLI command line interface ...  閱讀全文

posted @ 2007-05-10 23:23 wqwqwqwqwq 閱讀(991) | 評(píng)論 (0) | 編輯 收藏

F3(轉(zhuǎn)http://blogs.sun.com/chrisoliver/entry/f3)

     摘要: 據(jù)說(shuō)極有可能迅速取代目前流行的SWING和SWT技術(shù)。  閱讀全文

posted @ 2007-05-07 22:30 wqwqwqwqwq 閱讀(994) | 評(píng)論 (1) | 編輯 收藏

小“征”

北京今天有些風(fēng)，但是依然擋不住本有的悶熱。傍晚下樓吃飯，就像突然走進(jìn)蒸籠一樣的感覺(jué)，想象著眼前如果是大海該多好啊，說(shuō)到這真是慚愧，我在大連待了20多年，居然不會(huì)游泳，哎~...吃完飯，我從上地佳園溜達(dá)到公司，休息了一下。本想著看點(diǎn)書(shū)，但是這個(gè)時(shí)候似乎是快到下班的時(shí)間了，看著白領(lǐng)一族的匆匆離去、聯(lián)想圍欄旁悠然自得的粉刷小匠，我突然萌生要離開(kāi)這兒，去高校轉(zhuǎn)轉(zhuǎn)的念頭。
繞過(guò)DASCOM沿著信息路來(lái)到了五街，在路牌下等者656...我真的實(shí)在受不了了太陽(yáng)的直射和等車(chē)的煩躁，終于決定今天也學(xué)一次抗日前的長(zhǎng)征，學(xué)一次開(kāi)學(xué)前的軍訓(xùn)，...自己走到北大，也算熟悉熟悉一路的環(huán)境。現(xiàn)在回來(lái)我真的發(fā)現(xiàn)這是一個(gè)了不起的決定，因?yàn)檫@實(shí)在太累，走去五環(huán)-北大-四環(huán)，又跑回上地，即使在地圖上只能算作一指之距。想想先前走到北京體校時(shí)看見(jiàn)一個(gè)學(xué)生繞學(xué)校跑時(shí)的竊竊思緒，我更敬佩自己。腳累得很，但我也算是準(zhǔn)備好了這段時(shí)間出門(mén)在外的辛苦...RuiRui，你說(shuō)得很好，堅(jiān)持久了，也就好了。

posted @ 2007-05-07 21:40 wqwqwqwqwq 閱讀(448) | 評(píng)論 (0) | 編輯 收藏

標(biāo)準(zhǔn)字符集~

     摘要: 今天自己突然想起來(lái)整理一下標(biāo)準(zhǔn)的charset，感覺(jué)還算有必要。當(dāng)然java...  閱讀全文

posted @ 2007-05-06 19:50 wqwqwqwqwq 閱讀(621) | 評(píng)論 (0) | 編輯 收藏

活生生

昨天來(lái)得北京，準(zhǔn)備我以后幾個(gè)月的實(shí)習(xí)生活。北京還是和我原來(lái)來(lái)的感覺(jué)一樣，到處都是人流車(chē)流，太陽(yáng)總是離得很近，風(fēng)吹起的揚(yáng)塵讓我透不過(guò)氣...唯一使人感覺(jué)現(xiàn)代感的和不很疲憊的就是坐著北京的城鐵和地鐵，起碼它們不會(huì)因?yàn)樾苟Ｓ行┌参康氖亲贗BM的辦公大廳，我喜歡IT深邃的魅力，和品茶的悠然...
昨天一天十分疲倦，或許正如跟個(gè)遠(yuǎn)方的小弟在instantChat上所談的，這一天真的讓我品到了生活的很多酸澀和勞苦，我漸漸發(fā)現(xiàn)走路也是一件非常非常累得事情，漸漸發(fā)現(xiàn)與人相處的道理和囊中的羞澀。其實(shí)昨天一天就花了我3千多，房屋的中介賺得很多感覺(jué)，1200的房子，中介費(fèi)也要得1200，還有押金。不過(guò)房子我到是感覺(jué)還好，在上地佳園，至少感覺(jué)這的環(huán)境和保安還算可以，只是與人合租，不是很自在。
昨天也累壞了我一個(gè)高中同學(xué)，她陪我到處轉(zhuǎn)了一天，真的很謝謝她。
不知道下一步會(huì)如何，但是我得準(zhǔn)備好在這煎熬悶熱、運(yùn)籌自己的生活、學(xué)會(huì)太多太多...

posted @ 2007-05-06 12:24 wqwqwqwqwq 閱讀(464) | 評(píng)論 (0) | 編輯 收藏

Portal 門(mén)戶(hù)

     摘要: 這兩天找了一些portal相關(guān)的資料，也從中學(xué)到了很多東西。據(jù)說(shuō)我們學(xué)校還有個(gè)portal，不過(guò)現(xiàn)在不知為什么down掉了...  閱讀全文

posted @ 2007-04-27 20:48 wqwqwqwqwq 閱讀(2781) | 評(píng)論 (6) | 編輯 收藏

Temple of Sun Contest(official rules)__I think it's really a simple contest for 5000$ huge prize!

     摘要: Sun has rolled out the Temple of Sun Contest with a US$5,000 cash prize. This is a great vehicle to promote Sun Studio on campus.  閱讀全文

posted @ 2007-04-24 11:00 wqwqwqwqwq 閱讀(1358) | 評(píng)論 (2) | 編輯 收藏

ANT

     摘要: ANT是一個(gè)基于JAVA的自動(dòng)化腳本引擎，腳本格式為XML。除了做JAVA編譯相關(guān)任務(wù)外，ANT還可以通過(guò)插件實(shí)現(xiàn)很多應(yīng)用的調(diào)用。  閱讀全文

posted @ 2007-04-19 14:56 wqwqwqwqwq 閱讀(250) | 評(píng)論 (0) | 編輯 收藏

利用 Ant 和 JUnit 進(jìn)行增量開(kāi)發(fā)(轉(zhuǎn)載fromIBM)

     摘要: 軟件開(kāi)發(fā)習(xí)慣中一個(gè)細(xì)微更改都可能會(huì)對(duì)軟件質(zhì)量產(chǎn)生巨大改進(jìn)。將單元測(cè)試合并到開(kāi)發(fā)過(guò)程中，然后從長(zhǎng)遠(yuǎn)角度來(lái)看它可以節(jié)省多少時(shí)間和精力。本文通過(guò)使用代碼樣本說(shuō)明了單元測(cè)試的種種好處，特別是使用 Ant 和 JUnit 帶來(lái)的各種方便。  閱讀全文

posted @ 2007-04-19 14:52 wqwqwqwqwq 閱讀(477) | 評(píng)論 (0) | 編輯 收藏

ANT十五大最佳實(shí)踐(轉(zhuǎn)載)--o'reilly

     摘要: 在Ant出現(xiàn)之前，構(gòu)建和部署Java應(yīng)用需要使用包括特定平臺(tái)的腳本、Make文件、各種版本的IDE甚至手工操作的“大雜燴”。現(xiàn)在，幾乎所有的開(kāi)源 Java項(xiàng)目都在使用Ant，大多數(shù)公司的內(nèi)部項(xiàng)目也在使用Ant。Ant在這些項(xiàng)目中的廣泛使用自然導(dǎo)致了讀者對(duì)一整套Ant最佳實(shí)踐的迫切需求。  閱讀全文

posted @ 2007-04-19 14:45 wqwqwqwqwq 閱讀(489) | 評(píng)論 (0) | 編輯 收藏

Sun device detection tool

     摘要: By the way,there is a tool,Sun Device Detection Tool ,which is based on jnlp protocol, can tell us in just a few minutes whether the Solaris OS supports the devices that are detected in our x86 system, in advance.  閱讀全文

posted @ 2007-04-14 23:52 wqwqwqwqwq 閱讀(1277) | 評(píng)論 (0) | 編輯 收藏

利用google api寫(xiě)的小程序　

     摘要: 昨晚同學(xué)找我?guī)兔?xiě)一個(gè)利用GOOGLE API的小程序，也比較感興趣所以就應(yīng)下了。下載了GOOGLE提供的googleapi.jar，大約花了２０多分鐘，寫(xiě)了這個(gè)小程序，由于需要提供GOOGLE key所以也懶得去申請(qǐng)，就沒(méi)有測(cè)試～～呵呵  閱讀全文

posted @ 2007-04-14 15:22 wqwqwqwqwq 閱讀(3567) | 評(píng)論 (9) | 編輯 收藏

java與元數(shù)據(jù)

     摘要: 元數(shù)據(jù)是利用JDBC創(chuàng)建和操作數(shù)據(jù)庫(kù)對(duì)象的一個(gè)很重要的概念和應(yīng)用，所以今天我特地的找了一些詳細(xì)解析個(gè)概念的資料，和利用java來(lái)操作的實(shí)例。  閱讀全文

posted @ 2007-04-12 23:58 wqwqwqwqwq 閱讀(1722) | 評(píng)論 (0) | 編輯 收藏

java.security

出于java的安全限制，System.getProperty("line.seperator")是不能夠直接取得的。可以這樣做：

String lineSeparator = (String) java.security.AccessController.doPrivileged(
               new sun.security.action.GetPropertyAction("line.separator"));

具體參考java.io.BufferedWriter的源代碼就可以找到上面這行代碼。 DriverManager里也有

 1     private static void loadInitialDrivers() {
 2         String drivers;
 3 
 4         try {
 5             drivers = (String) java.security.AccessController
 6                     .doPrivileged(new sun.security.action.GetPropertyAction(
 7                             "jdbc.drivers"));
 8         } catch (Exception ex) {
 9             drivers = null;
10         }
11         println("DriverManager.initialize: jdbc.drivers = " + drivers);
12         if (drivers == null) {
13             return;
14         }
15         while (drivers.length() != 0) {
16             int x = drivers.indexOf(':');
17             String driver;
18             if (x < 0) {
19                 driver = drivers;
20                 drivers = "";
21             } else {
22                 driver = drivers.substring(0, x);
23                 drivers = drivers.substring(x + 1);
24             }
25             if (driver.length() == 0) {
26                 continue;
27             }
28             try {
29                 println("DriverManager.Initialize: loading " + driver);
30                 Class.forName(driver, true, ClassLoader.getSystemClassLoader());
31             } catch (Exception ex) {
32                 println("DriverManager.Initialize: load failed: " + ex);
33             }
34         }
35     }

sun.security.action.GetPropertyAction() hasn't been publiced.actually and exactly,it's not be doced,which reflects that sun doesn't surport us to use these class or method which is lower class,usually, we use the classes api tells us is proier and maybe has called these undoc class  but usually for us ,it's not necessary.so in the program of us or even others ,we could and i think it's really better for us to neglect  them which u can find out in the jar file of rt.jar.

posted @ 2007-04-11 16:35 wqwqwqwqwq 閱讀(566) | 評(píng)論 (0) | 編輯 收藏

Java性能優(yōu)化（摘錄）

     摘要: 可供程序利用的資源（內(nèi)存、CPU時(shí)間、網(wǎng)絡(luò)帶寬等）是有限的，優(yōu)化的目的就是讓程序用盡可能少的資源完成預(yù)定的任務(wù)。優(yōu)化通常包含兩方面的內(nèi)容：減小代碼的體積，提高代碼的運(yùn)行效率。本文討論的主要是如何提高代碼的效率。  閱讀全文

posted @ 2007-04-09 11:12 wqwqwqwqwq 閱讀(475) | 評(píng)論 (0) | 編輯 收藏

JAVA ONLINE項(xiàng)目

1.變量引用的時(shí)候,空指針情況的防止,即為空檢查.
2.數(shù)學(xué)運(yùn)算異常,如除0的情況.數(shù)組越界異常,字符串訪問(wèn)過(guò)界
3.數(shù)據(jù)庫(kù)檢索記錄,結(jié)果記錄行數(shù)狀況的處理.
4.畫(huà)面顯示項(xiàng)目的確認(rèn).
5.畫(huà)面顯示項(xiàng)目達(dá)到上限時(shí)情況的處理.
6.系統(tǒng)出錯(cuò)的時(shí)候,異常信息是否正確.
7.數(shù)據(jù)庫(kù)連接,游標(biāo)的處理.
8.數(shù)學(xué)運(yùn)算時(shí),數(shù)據(jù)精度的處理.

posted @ 2007-04-09 11:06 wqwqwqwqwq 閱讀(222) | 評(píng)論 (0) | 編輯 收藏