﻿<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:trackback="http://madskills.com/public/xml/rss/module/trackback/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/"><channel><title>BlogJava-Xiaobo Sun -随笔分类-UML</title><link>http://www.blogjava.net/sunxiaobo/category/28820.html</link><description>Eclipse-Europa
http://umlfact.berlios.de/~s_xsun/</description><language>zh-cn</language><lastBuildDate>Wed, 09 Jan 2008 05:10:51 GMT</lastBuildDate><pubDate>Wed, 09 Jan 2008 05:10:51 GMT</pubDate><ttl>60</ttl><item><title>Composition &amp; Aggregation</title><link>http://www.blogjava.net/sunxiaobo/archive/2007/07/12/129962.html</link><dc:creator>Xiaobo Sun</dc:creator><author>Xiaobo Sun</author><pubDate>Thu, 12 Jul 2007 15:39:00 GMT</pubDate><guid>http://www.blogjava.net/sunxiaobo/archive/2007/07/12/129962.html</guid><wfw:comment>http://www.blogjava.net/sunxiaobo/comments/129962.html</wfw:comment><comments>http://www.blogjava.net/sunxiaobo/archive/2007/07/12/129962.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/sunxiaobo/comments/commentRss/129962.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/sunxiaobo/services/trackbacks/129962.html</trackback:ping><description><![CDATA[Composition: b's lifetime is up to its context (object of A).<br />
==C++==<br />
class A{<br />
&nbsp;&nbsp;&nbsp; B b;<br />
}<br />
==java==<br />
class A{<br />
&nbsp;&nbsp;&nbsp; B b;<br />
&nbsp;&nbsp;&nbsp; public A(){<br />
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp; b = new B();<br />
&nbsp;&nbsp;&nbsp; }<br />
}<br />
<br />
Aggregation: b can live without its context (object of A).<br />
============================================<br />
==C++==<br />
class B{<br />
&nbsp;&nbsp;&nbsp; B* b;<br />
}<br />
==java==<br />
class B{<br />
&nbsp;&nbsp;&nbsp; B b;<br />
&nbsp;&nbsp;&nbsp; public A(B b){<br />
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp; this.b = b;<br />
&nbsp;&nbsp;&nbsp; }<br />
}<br />
<br />
<img src ="http://www.blogjava.net/sunxiaobo/aggbug/129962.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/sunxiaobo/" target="_blank">Xiaobo Sun</a> 2007-07-12 23:39 <a href="http://www.blogjava.net/sunxiaobo/archive/2007/07/12/129962.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>