george.gu
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george.gu：
lqjacklee 写道怎么解决。。 First: Conf ...
Bad version number in .class file -
lqjacklee：
怎么解决。。
Bad version number in .class file -
flyqantas：
would you pleade left more mate ...
UML Extension
文章列表
Second level cache
Ehcache in hibernate
Hibernate batch load
Use hibernate batch load feature to refresh a set of managed data in order to avoid memory leak and improve performance.
Hibernate interceptor
Used to customize some data to add or remove some information before oper ...
AOP(3): Spring AOP
- 博客分类：
- 随笔
AOP References
Please refer to Spring Framework AOP specification site for more details on spring aop concepts.
General introduction to Aspect-Oriented Programming
Aspect
Aspect is "cross-cutting concern". For example:
Transaction Management Aspect
Logging Aspect
Security A ...
log4j Usage
- 博客分类：
- log4j
In our projects, there are always the following questions for log4j integration:
log4j could be exist in several jars, is there any conflict? For example, each components has their own logging implementation, is there any problem/conflict?
Why log4j.xml is provided but log4j.properties is always i ...
What's saved in Object Reference?
We can treat the Java Object will be managed in two parts:
Obejct definition and its reference to Memory Heap which contains object's attribute and data contents.
Data contents in memory heap which is known by Object by reference.
The following Junit test co ...
UML Extension
- 博客分类：
- 随笔
Classes Relationship in UML
Association
"Association" on behelf of the reference between Class A and Class B. Association allows one class to know the methods and attributes of referenced class.
Normally, referenced Class is attribute of host Class.
One-direction asscociation:
Class ...
Oracle Index Usage
- 博客分类：
- 每日一得
Like a hash mapping for record's address. By default sql query Will lead to entire schema scanning. Index can be Used to get target record fastly and easily.
I met a problem this afternoon when test following souce snap:
Properties p = new Properties(); #1
p.put("smsc.adapter.driver.number", 2); #2
int driverNumbers = Integer.intValue(p.getProperty("smsc.adapter.driver.number")); #3
Yes, there is a Nullpointer Exception in ...
There is long times since last time I did use JMX in my project. Too long to remember all details on how to use JMX. We can refer to Java website to get more details on how to use JMX: http://www.oracle.com/technetwork/java/javase/tech/best-practices-jsp-136021.html.
In order to keep well understo ...
What's Taglib?
Taglib is a JSP extension feature to allow developer to define complex UI interactivation in java code. It can simplify the code and logical in JSP page and we can control the JSP page display in java code.
How to implement Taglb?
Any java code that wants control JSP page displ ...
QA is important for production. Testing is important for QA.
Here I would like to talk about testing in Java application development. It won't refer to project process/life cycle control, I will only talk something about automatically unit testing.
Test Data Design and Populate
There are alwa ...
使用动态代理(JDK Proxy 或者Cglib Proxy)的时候，如果打印出代理对象的话，发现一些配置的消息也会被打印。原来是因为Proxy调用对象类的toString()方法时也通过invoke(JDK Proxy)或者intercept(Cglib Proxy)。
总结一下Proxy, CGlig 的使用、原理、
分析Spring中如何通过Proxy, CGlig实现AOP 动态代理。
I had heared about AOP almost 7 years but only used it in two projects. 7 Years, I still only know few about AOP, if i were not involved in that two projects, i would still know that few.
The fact is always like that:
Hear about it.
Know how to use it.
Use it in project
Know what's problem i ...
今天讨论问题时，有个同事说系统A是主动去系统B里“拿”消息，我们把它称为“pull”模式。他认为pull方式效率比较低，为什么不用“push”模式呢。就是说让系统B收到消息主动通知并把消息发给系统A。
我认为他说的是对的。
可是老板给我们讲了一个故事，让我觉得单纯从模式的角度来探讨系统性能有点“坐井观天”。
如果系统B通知系统A之后，系统A会消费这条消息，如果这个处理过程包含一系列的复杂操作，那么这个时候系统B在做什么呢？在等！系统B block等待系统A的返回境况。哈哈，我们发现系统B的效率很慢，但是不是有本身引起的。
我们就不能简单地说push就比pull好了。
事实上，以上 ...
You can find velocity mannual from http://velocity.apache.org/engine/devel/user-guide.html.
Here is summarize on how to use velocity.
Velocity Usage:
Velocity is a Java-based template engine.
We can use velocity to define web page instead of JSP, there are several advantages:
It permits ...
In current Project, we need to parse log file (written by log4j) and extract dedicated information for future actions:
Display info in GUI
Analyze error and send mail to responder
Backup key logs into DB which can be shared to external system
...
Oh, what's the topic I am going to talk in t ...