Vincent Partington: Top 10 Java EE performance problems

Vincent Partington: Top 10 Java EE performance problems

For the last two and a half months, Vincent Partington has been blogging about the top ten Enterprise Java Application Performance Problems. The list:

• #10 - Excessive logging
• #9 - Incorrect application server configuration
• #8 - Incorrect usage of Java EE
• #7 - Unnecessary use of XML
• #6 - Improper caching
• #5 - Excessive memory usage
• #4 - Badly performing libraries
• #3 - Incorrectly implemented concurrency
• #2 - Unnecessary remoting
• #1 - Incorrect database usage

Now he wraps up the countdown with some conclusions about Enterprise Java performance in general:

• First of all, Java developers should consider performance an importance quality requirement of their application to which they should pay attention from the start to the end of the project.
• Secondly, Java developers need to work with the people that can help them improve the performance of their application like application server and database administrators.

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在局域网内部实现MSN通讯服务 资讯中心-计世网

在局域网内部实现MSN通讯服务 资讯中心-计世网

MSNMessengerService集即时消息、网络电话、自动检查邮件等功能于一体，很受广大"网虫"的喜爱，但是您知道吗，MSNMessengerService不但可以登录到MSN的Messenge rServer，还可以登录到局域网内的ExchangeServer呢！无需连接到Internet，您一样可以享受MSNMessengerService的强大功能！

下面笔者就如何建立局域网内部的通讯服务做详细介绍：

前提条件

网络中有一台计算机安装了MicrosoftExchangeServer2000（MicrosoftExchangeServer2000的安装方法不是本文重点，所以不做介绍了。详情请参阅： http://support.microsoft.com）。

准备工作

1、一张MicrosoftExchangeServer2000安装光盘。

2、下载MSNMessengerService的最新版本（ http://messenger.msn.com/lccn）。

安装与设置过程

一、添加ChatServices和InstantMessagingServices

1、将MicrosoftExchangeServer2000安装光盘放入服务器光驱，单击"ExchangeServerSetup"。

2、当出现"MicrosoftExchangeInstallation向导"时，单击"下一步"。在"Action"栏选择"Change"，将ChatServices和InstantMessagingServices都选择成"Install"，单击"下一步"安装向导会自动完成安装任务。

二、配置InstantMessaging

1、单击"开始"，指向"程序→MicrosoftExchange"，单击"SystemManager"，双击"Servers"，双击您的计算机名，双击" Protocols"，右击"InstantMessaging（RVP）"，选择"新建"，单击"InstantMessagingVirtualServer"，在DisplayName栏中输入配置文件名。

2、单击"下一步"，在ChooseIISWebSite中选择Web站点。单击"下一步"，在DN SDomainName栏中输入DNS名（例如：home.net），此DNS名将作为用户登录邮件地址@符号后面的部分。单击"下一步"，在"Allowthisservertohostaccounts"前面打勾，使配置文件马上生效，配置完成后建议重新启动服务器。

三、配置用户账户

1、在"管理工具"中单击"ActiveDirectory用户和计算机"，单击"Users"，任意选择一个用户（例如：administrator），双击账户，在"ExchangeFeatures"选项卡中，选中"InstantMessaging"。

2、单击"Enable→Browse"，在"ServerName"中选择配置文件名，单击"确定"。回到上一级选项卡。单击"确定"，即完成用户账户配置。

四、安装、配置MSNMessengerService

1、将MicrosoftExchangeServer2000安装光盘放入客户机光驱；在客户机，单击"开始→运行"，键入"X:INSTMSGI386CL IENTCHSMMSSETUP.EXE"（X代表您的光驱的盘符），开始安装MSNMessengerService2.2forExchange。

2、MSNMessengerService2.2forExchange安装完毕后，再安装您从网上下载的MSNMessengerService3.x。

3、安装完毕后在MSNMessengerService3.x主窗口， 单击"工具"；选择"选项"，在"账户"选项卡中的"首先用此账户登录"选项中选择"Exchange账户"在Exchange账户"登录名"框中输入登录名 administrator@home.net。

4、单击"确定"，选择"单击这里登录"，即可登录到MicrosoftExchangeServer2000InstantMessagingService。

注意：您必须首先安装MSNMessengerService2.2forExchange，然后再升级到MSNMessengerService3.x才能有登录到MicrosoftExchangeServer2000InstantMessagingService的选项，否则MSNMessengerService3.x中将没有登录到MicrosoftExchangeServer2000InstantMessagingService选项 。

5、重复3、4步即可创建、配置用户账户及客户端。

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Yod'm 3D - About - Visual Tooltip

Yod'm 3D - About - Visual Tooltip: "Yet anOther Desktop Manager 3D
( Windows 2000/XP/Vista )
( DirectX 9 required )




Yod'm 3D is a virtual desktop manager with the fashionable effect : the cube





By default, the rotation of the cube is done with the keys CTRL+SHIFT+Arrows :

* CTRL+SHIFT+Left/Right = Next/prev desktop

* CTRL+SHIFT+Up = Activate and show a 'far' view of the current desktop, Left and right to turn the cube

* CTRL+SHIFT+Down = Activate and show a 'near' view of the current desktop, Left and right to turn the cube

Hold down CTRL+SHIFT to use the mouse to turn the cube.
( The rotation is possible only horizontally )" Read more ...

Enum Types (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

Enum Types (The Java™ Tutorials > Learning the Java Language > Classes and Objects): "Java programming language enum types are much more powerful than their counterparts in other languages. The enum declaration defines a class (called an enum type). The enum class body can include methods and other fields. The compiler automatically adds some special methods when it creates an enum. For example, they have a static values method that returns an array containing all of the values of the enum in the order they are declared. This method is commonly used in combination with the for-each construct to iterate over the values of an enum type. For example, this code from the Planet class example below iterates over all the planets in the solar system.

for (Planet p : Planet.values()) {
System.out.printf('Your weight on %s is %f%n',
p, p.surfaceWeight(mass));
}" Read more ...

Nested Classes (The Java™ Tutorials > Learning the Java Language > Classes and Objects)

Nested Classes (The Java™ Tutorials > Learning the Java Language > Classes and Objects): "A nested class is a member of its enclosing class and, as such, has access to other members of the enclosing class, even if they are declared private. As a member of OuterClass, a nested class can be declared private, public, protected, or package private. (Recall that outer classes can only be declared public or package private.)

Terminology: Nested classes are divided into two categories: static and non-static. Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes." Read more ...

60 best CSS directories you would die to watch! at Witty Sparks

60 best CSS directories you would die to watch! at Witty Sparks: "With new technologies flooding the web,different tools are available with which a web designer can showcase his creativity and craft. But despite putting in the effort and sweat, numerous websites with fantastic creativity fail to get noticed. Also, the surge in designing is driving designers to dig for creativity, color schemes and layouts.

Keeping these aspects in mind, we came up with a compendium of best CSS directories, CSS showcase, CSS galleries that rank / grade websites (using CSS) on the basis of ‘alexa ranking’, colors, categories, tags, ratings and RSS.

If you feel that a particular site is worth to get showcased, then drop the URL’s in your comments so that they become a part of our next list.

If you found this article useful, digg it to ensure that a designer’s effort doesn’t go unnoticed." Read more ...

MSSQL数据库移植后的用户权限问题

把数据库备份还原到另一个服务器时，可能会遇到孤立用户的问题
举例：数据库test有用户U_tom，对应的登录帐户为L_tom,按以下步骤操作将会出现孤立用户U_tomf:

备份test->删除数据库test->删除登录L_tom->还原test

查看：
1、企业管理器->展开要查看的数据库->用户 ，会发现相应的用户没有对应的登录
2、在查询分析器中执行 EXECsp_change_users_login @Action='Report'

解决：
办法一、自动新增一个和用户名相同的登录帐户，并影射
EXEC sp_change_users_login 'Auto_Fix', 'U_tom'

办法二、新增一个登录帐户，然后将此登录帐户映射到孤立的用户
EXEC sp_addlogin 'L_tom'
--Change the user account to link with the 'L_tom' login.
EXEC sp_change_users_login 'Update_One', 'U_tom', 'L_tom'

或者:
1、找到该用户的ID 例如：
select sid from sysusers where name='U_tom'
结果为
0x67E19EC564D7344CB19AC35085C1A36B

2、新增一个登录帐户L_tom，将此登录帐户映射到孤立的用户
EXEC sp_addlogin @loginame = 'L_tom',
@sid = 0x67E19EC564D7344CB19AC35085C1A36B

参考：sp_change_users_login 、sp_addlogin 的语法参考 Read more ...