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转自:http://elf8848.iteye.com/blog/811037   classes12.jar,ojdbc14.jar,ojdbc5.jar和ojdbc6.jar的区别,之间的差异     在使用Oracle JDBC驱动时,有些问题你是不是通过替换不同版本的Oracle  JDBC驱动来解决的?最常使用的ojdbc14.jar有多个版 ...
转: java.sql.SQLException: 违反协议异常的一种解释   转自:http://willam2004.iteye.com/blog/900077   一次做应用升级出现了一个问题,描述如下:    升级分为两块,一块是数据库结构变更(表结构增加新字段);一块是应用程序的升级。    应用环境为:jboss4.0.5 + ibatis + spring 数据源在jboss的oracle-ds.xml文件中进行配置,通过spring的jndi方式进行查找 。    我先将数据库进行升级,更改表结构(增加字段),因为应用中的ibatis的查询采用的是ResultMap返回 ...
The specific goals bound to each phase default to a set of goals specific to a project’s packaging. A project with packaging jar has a different set of default goals from a project with a packaging of war. The packaging element affects the steps required to build a project. For an example of how t ...

java volatile

volatile is a keyword. When member variables are marked with this keyword, it changes the runtime behavior in a way that is noticeable when multiple threads access these variables. Without the volatile keyword, one thread could observe another thread update member variables in an order that is not c ...

java native

native is a java keyword. It marks a method, that it will be implemented in other languages, not in Java. It works together with JNI(Java Native Interface) Syntax: [public|protected|private] native method(); Native methods were used in the past to write performance critical sections but with ja ...

java transient

transient is a Java keyword which marks a member variable not to be serialized when it is persisted to streams of bytes. When an object is transferred through the network, the object needs to be 'serialized'. Serialization converts the object state to serial bytes. Those bytes are sent over the netwo ...
这段时间系统上出现一个很怪异现象,即生成很多重复订单,从生成时间上看,有同一时间的,也有相隔几分钟的。开始怀疑是程序上的问题,排查程序,没有找到问题原因。进而怀疑是nginx的配置问题,那么先需要证明这个怀疑。要证明这个怀疑就得找到--通过nginx的http请求与生成订单的关联,即客户端的一个请求,在nginx上被处理了两次。   办法:加日志。   1. nginx日志:加上客户端IP和请求会话的sessionid。 ip:使用Nginx作为反向代理时,后端应用服务器日志记录的客户端IP就不是真实的客户端IP,而是Nginx代理的IP。要解决这个问题可以在Nginx配置一个新的He ...
    Enabling HTTP request response logging on JBoss 4.2 转自:http://blog.leenarts.net/2010/08/26/http-request-response-logging-jboss-4-2/ Today I had a bit of a fiddle with JBoss 4.2 due to IE7/IE8 compatibility differences. When opening or downloading a file in IE7 over an SSL connection (HTT ...
在说问题前,先扫下盲,关于linux下的nobody用户:   nobody是系统用户,是一个不能登陆的帐号,一个特殊用途的用户 ID ,一些服务进程如apache,aquid等都采用一些特殊的帐号来运行,比如nobody,news,games等等。一般来说 uid < 500 的都是系统 ID 。 Linux 系统为了安全,很多操作和服务的运行都不是运行在 root 用户下面的,而是一个专用的 ID ,这个 ID 一般就是 nobody ,这样就可以把每个服务运行的情况隔离出来。保证不会因为服务器程序的问题而让服务器程序成了黑客的直接操作源(黑客拿下了服务器程序,也仅仅是 nobo ...
转自:http://wiki.zimbra.com/wiki/NGINX_Log_Customization You can customize Nginx logs in order to get more detailed information. For example, in order to get session cookie information on nginx.access.log, you can do the following (make sure you have done a backup on all the files that are going to ...
  Multiple Component Instances with OSGi Declarative Services When we define a component using OSGi Declarative Services (DS), by default we are defining a singleton. For example using the Bnd annotation syntax we can define a component as follows: @Component public class MyComponent implements ...
转:我在Facebook的十点经验分享 - 非反人类文字版 本文转自http://blog.sina.com.cn/hwang123 我是2007年初加入Facebook, 那时大概150人; 2011年9月底离开, 当时3200多人. 经历了很多稀奇古怪但影响很大的项目, 像Application Platform, Social Ads, News Fe ...
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