Session Pool Design

1. 利用apache common-pool实现一个Session Pool（非常简单）
2. 如何避免代码中的returnObject()?

       xxx()            invoke
        --------> PoolProxy ---> PoolInterceptor      SessionPool
                                           borrowObject()
                                          --------------->
                                          <---------------


                                                   xxx()       Session (be borr
owed)
                                          -------------------------------->

                                           returnObject()
                                          ---------------->


--

RMI design

xxx()            invoke               Serialize call to remote
-----> ClientProxy ---> RmiInterceptor ------------------->

         find ServerProxy, xxx()               xxx()
RmiServer----------------> ServerProxy --->....-->ServerObject

Method Cache design

1.用HashMap做cache

xxx()       invoke
-----> Proxy ---> MCInterceptor
                       1. get Attribute @timeout
                       2. 用object[]作为key，看cache中的
                       结果是否超时

                       3. 如果超时     invoke
                         ------------------> NextInterceptor...
                       4. 如果不超，返回被cache的结果
Draw activity UML diagram:

1. 实现绘图模块
xxx()      invoke
---> Proxy ---> ActivityIntercpetor
                             draw xxx()
                        --------------->绘图模块
                            invoke
                        --------------------------->NextInterceptor...

Persistence and descriptive transaction

1. Persistence直接使用hibernate


xxx       invoke
---->Proxy-->HibernateInterceptor
                                1. 取得@tx，应该为required,requiresnew
                                ,supports,notsupported中的一种
                                2. 判断当前的transaction状态
                                3. 决定本次调用是否在transaction当中
Folder-Node关系的复用


getFolder()   getFolder()         invoke              getFolder()
  --->UserProxy ------> NodeProxy -->SideEntityInterceptor--> Node
                                                        return Folder
                                                        <-----
                                             根据Folder创建Group proxy
                                  返回GroupProxy
                                  <----


in the code, like this:

...
User user = userFactory.find("guty"); //user is actually a proxy
Group group = (Group)((Node)user).getFolder();