﻿<?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>语源科技BlogJava-Java学习空间</title><link>http://www.blogjava.net/elven/</link><description>Java新人</description><language>zh-cn</language><lastBuildDate>Thu, 30 Apr 2026 06:26:35 GMT</lastBuildDate><pubDate>Thu, 30 Apr 2026 06:26:35 GMT</pubDate><ttl>60</ttl><item><title>web服务器问题</title><link>http://www.blogjava.net/elven/archive/2008/02/27/182562.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Wed, 27 Feb 2008 13:45:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2008/02/27/182562.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/182562.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2008/02/27/182562.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/182562.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/182562.html</trackback:ping><description><![CDATA[本公司有两台服务器，均由远程服务器托管机房管理。 <br />
两台服务器均是linux操作系统，一台做数据库服务器（以下称它为218），一台做web服务器（以下称它为220），两台服务器在一个局域网中。 <br />
一般情况下，我们只能通过ssh和SecureFX访问这两台服务器。 <br />
但是这几天出现个问题：我们用ssh连接220速度很慢，甚至多数情况下连接不上，同时ping &nbsp; 220也是经常出现&#8220;掉包&#8221;现象，而218连接速度正常，因为两台服务器在同一个局域网中，于是我们可以通过218连接220，登录上220时发现一切正常。很是郁闷，始终找不到原因。 <br />
请高手帮忙分析一下可能存在的问题，在下不甚感激！
<img src ="http://www.blogjava.net/elven/aggbug/182562.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2008-02-27 21:45 <a href="http://www.blogjava.net/elven/archive/2008/02/27/182562.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>xmlhttp跨域问题</title><link>http://www.blogjava.net/elven/archive/2007/12/23/169730.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Sun, 23 Dec 2007 03:56:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/12/23/169730.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/169730.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/12/23/169730.html#Feedback</comments><slash:comments>0</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/169730.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/169730.html</trackback:ping><description><![CDATA[<p>最近在实现一个在html静态页面中动态显示客户评价的程序的时候遇到xmlhttp跨域问题，请求解决方法：<br />
需求：<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 本网站是一个B2B的电子商务平台（<a href="http://www.easyeb.com">www.easyeb.com</a>），在用户注册一个高级会员时，我们的工作人员会为其分配一个二级域名（例如wyyy.easyeb.com）的网上商铺，而我们的网上商铺都是静态页面的（根据会员的资料生成的html文件，组成其网上商铺），而在这个网上商铺中，我们有一个页面是用来显示会员评价的，会员评价可以按性质（好评，中评，差评）和评价者身份（买家和卖家），在这个页面上，我们需要实现按浏览者意图动态显示评价内容（例如，浏览者想查看该会员得到的好评，他在下拉式列表框中选择&#8220;好评&#8221;，我们就可以显示所有好评的评价内容...）。<br />
实现及问题：<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 在实现是我们采用了ajax式的方式，通过xmlhttp动态访问服务器端的servlet而取得数据，但是在其过程中出现一个问题：动态取得数据的servlet被配置在<a href="http://www.easyeb.com">www.easyeb.com下，而xmlhttp要在</a>wyyy.easyeb.com通过访问servlet取得数据（xmlhttp.open("GET",http://www.easyeb.com/servlet,true)），js的安全策略认为xmlhttp跨域访问（从wyyy.easyeb.com访问<a href="http://www.easyeb.com">www.easyeb.com下的servlet</a>），始终提示js错误——&#8220;拒绝访问&#8221;。<br />
我该怎么办呢？在页面中设置document.domain属性试过了，它要求在所有页面中都设置，那我在servlet中怎么设置呢？这个方法我们没有走通。请求其他解决办法。<br />
本网站服务器构架（apache+tomcat5.0）</p>
<img src ="http://www.blogjava.net/elven/aggbug/169730.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-12-23 11:56 <a href="http://www.blogjava.net/elven/archive/2007/12/23/169730.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>还是struts2问题</title><link>http://www.blogjava.net/elven/archive/2007/08/30/141491.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Thu, 30 Aug 2007 11:08:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/30/141491.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/141491.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/30/141491.html#Feedback</comments><slash:comments>2</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/141491.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/141491.html</trackback:ping><description><![CDATA[我是一个struts2的初学者，按照<a href="http://www.blogjava.net/elven/admin/www.blogjava.net/max"><u><font color=#0000ff>max</font></u></a>的方法建了一个struts2的工程，目录结构如下图：<br>&nbsp;<img alt="" src="http://www.blogjava.net/images/blogjava_net/elven/project.jpg" border=0><br>在WebContent目录下建一个名叫index.html的页面，在tomcat中配置虚拟路径<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">Context&nbsp;path</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">/struts2</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;docBase</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">F:\Struts2.0\WebContent</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;debug</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;crossContext</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">true</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;reloadable</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">true</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">/&gt;</span></div>
然后重起tomcat，在浏览器中输入<a href="http://localhost:8080/struts2"><u><font color=#0000ff>http://localhost:8080/struts2</font></u></a><br>提示：HTTP Status 404 - /struts2/。<br>但是，当我在tomcat配置虚拟路径时，这样配置<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">Context&nbsp;path</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">/struts2</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;docBase</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">F:\Struts2.0</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;debug</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">0</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;crossContext</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">true</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">&nbsp;reloadable</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">true</span><span style="COLOR: #000000">"</span><span style="COLOR: #000000">/&gt;</span></div>
重起tomcat，在浏览器中输入<a href="http://localhost:8080/struts2/WebContent"><u><font color=#0000ff>http://localhost:8080/struts2/WebContent</font></u></a>，这时浏览器中就可以显示出index.html页面。<br>为什么会出现这种情况呢？<br>但是我在建其他工程，非struts2的工程的时候，就不会出现这种情况，难道是我的tomcat5.5不支持struts2吗？也不可能啊。
<img src ="http://www.blogjava.net/elven/aggbug/141491.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-30 19:08 <a href="http://www.blogjava.net/elven/archive/2007/08/30/141491.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>连不上ssh，linux</title><link>http://www.blogjava.net/elven/archive/2007/08/26/139481.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Sun, 26 Aug 2007 07:05:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/26/139481.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/139481.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/26/139481.html#Feedback</comments><slash:comments>1</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/139481.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/139481.html</trackback:ping><description><![CDATA[我在xp系统下利用虚拟机安装了一个linux系统，但是怎么配置都无法访问利用ssh访问我虚拟机下的linux呢。<br>补充：可以ping通，但是telnet不能访问，是不是端口没打开呢？但是我查看了端口配置22、23等端口都是打开的啊。<br>还有在关闭linux的防火墙的时候，为什么总是关不掉呢？每次setup进去后选择No firewall保存，再打开时，Security Level又变成Hight了，这又是怎么回事呢？
<img src ="http://www.blogjava.net/elven/aggbug/139481.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-26 15:05 <a href="http://www.blogjava.net/elven/archive/2007/08/26/139481.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>struts2.0</title><link>http://www.blogjava.net/elven/archive/2007/08/21/138453.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Tue, 21 Aug 2007 13:46:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/21/138453.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/138453.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/21/138453.html#Feedback</comments><slash:comments>6</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/138453.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/138453.html</trackback:ping><description><![CDATA[&nbsp;&nbsp;&nbsp;&nbsp; 摘要: 看了blogjava上max老师关于Struts2.0的文章，于是开始学习Struts2.0了。但是始终会出现问题。我严格按照max老师的《为Struts 2.0做好准备》中的方法，一步一步地建立了我的第一个Struts2.0的Project——Struts2_HelloWorld。        到Apache下载Struts 2.0包         打开Eclipse 3...&nbsp;&nbsp;<a href='http://www.blogjava.net/elven/archive/2007/08/21/138453.html'>阅读全文</a><img src ="http://www.blogjava.net/elven/aggbug/138453.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-21 21:46 <a href="http://www.blogjava.net/elven/archive/2007/08/21/138453.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>开通泛域名后，tomcat和apache的配置问题</title><link>http://www.blogjava.net/elven/archive/2007/08/12/136136.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Sun, 12 Aug 2007 02:16:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/12/136136.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/136136.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/12/136136.html#Feedback</comments><slash:comments>-2</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/136136.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/136136.html</trackback:ping><description><![CDATA[<p>我们网站现在出现一个问题：<br>开通泛域名之前，<a href="http://www.test.com/">www.test.com是可以正常访问的，并且</a>test的二级域名例如bbs.test.com也是可以正常访问的，但是在开通泛域名*.test.com之后，网站就不能正常访问了或者访问速度非常慢。<br>请问：这是什么原因呢？在开通泛域名之后，tomcat和apache的配置需要怎样变动吗？</p>
<img src ="http://www.blogjava.net/elven/aggbug/136136.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-12 10:16 <a href="http://www.blogjava.net/elven/archive/2007/08/12/136136.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>还是Tomcat问题——网站不能正常访问</title><link>http://www.blogjava.net/elven/archive/2007/08/09/135512.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Thu, 09 Aug 2007 07:30:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/09/135512.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/135512.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/09/135512.html#Feedback</comments><slash:comments>1</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/135512.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/135512.html</trackback:ping><description><![CDATA[Tomcat配置好后，在地址栏输入域名。<br>tomcat在编译JSP时，出现找不到JSP使用的类的情况。<br>例如：<a href="http://www.xxxx.com/login/login.jsp出错：">www.xxxx.com/login/login.jsp出错：</a><br>An error occurred at line: 7 in the jsp file: /login.jsp<br>Message cannot be resolved to a type<br>而在地址栏输入IP地址确没有问题，而且在输入IP进行访问时，网站可以正常运行。<br>例如：<a href="http://192.168.77.55:8080/login/login.jsp">http://192.168.77.55:8080/login/login.jsp这样访问</a>时，网站是正常的。<br>还有就是网站在访问静态页面html时，不管是输入IP地址还是域名，网站都可以正常访问。<br>请问这是什么原因？
<img src ="http://www.blogjava.net/elven/aggbug/135512.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-09 15:30 <a href="http://www.blogjava.net/elven/archive/2007/08/09/135512.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>Tomcat启动不了！</title><link>http://www.blogjava.net/elven/archive/2007/08/06/134743.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Mon, 06 Aug 2007 09:22:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/06/134743.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/134743.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/06/134743.html#Feedback</comments><slash:comments>1</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/134743.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/134743.html</trackback:ping><description><![CDATA[在启动Tomcat的时候出现如下错误。<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top><span style="COLOR: #000000">java.lang.reflect.InvocationTargetException<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;sun.reflect.NativeMethodAccessorImpl.invoke0(Native&nbsp;Method)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:</span><span style="COLOR: #000000">39</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:</span><span style="COLOR: #000000">25</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;java.lang.reflect.Method.invoke(Method.java:</span><span style="COLOR: #000000">585</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:</span><span style="COLOR: #000000">271</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:</span><span style="COLOR: #000000">409</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>Caused&nbsp;by:&nbsp;java.lang.NoClassDefFoundError:&nbsp;org</span><span style="COLOR: #000000">/</span><span style="COLOR: #000000">apache</span><span style="COLOR: #000000">/</span><span style="COLOR: #000000">commons</span><span style="COLOR: #000000">/</span><span style="COLOR: #000000">logging</span><span style="COLOR: #000000">/</span><span style="COLOR: #000000">LogFactory<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.naming.NamingContext.</span><span style="COLOR: #000000">&lt;</span><span style="COLOR: #000000">clinit</span><span style="COLOR: #000000">&gt;</span><span style="COLOR: #000000">(NamingContext.java:</span><span style="COLOR: #000000">57</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:</span><span style="COLOR: #000000">207</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:</span><span style="COLOR: #000000">119</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.core.StandardServer.start(StandardServer.java:</span><span style="COLOR: #000000">676</span><span style="COLOR: #000000">)<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>&nbsp;&nbsp;&nbsp;&nbsp;at&nbsp;org.apache.catalina.startup.Catalina.start(Catalina.java:</span><span style="COLOR: #000000">537</span><span style="COLOR: #000000">)</span></div>
它的意思好像是找不到commons-logging.jar包，但是以前我启动Tomcat的时候就没有这个包，还是可以启动的，今天由于修改了一些东西，所以出现这样的错误，但是我又把Tomcat的配置还原成修改以前的状态，还是出现这样的错误。<br>我的问题：（1）commons-logging.jar，此包要放在什么位置，tomcat启动时才找得到？<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;（2）commons-logging.jar，此包的作用的是什么？<br>请各位大哥大姐帮帮忙，小弟万分感激！！！
<img src ="http://www.blogjava.net/elven/aggbug/134743.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-06 17:22 <a href="http://www.blogjava.net/elven/archive/2007/08/06/134743.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item><item><title>一个if-else的问题</title><link>http://www.blogjava.net/elven/archive/2007/08/02/133964.html</link><dc:creator>Elven</dc:creator><author>Elven</author><pubDate>Thu, 02 Aug 2007 03:52:00 GMT</pubDate><guid>http://www.blogjava.net/elven/archive/2007/08/02/133964.html</guid><wfw:comment>http://www.blogjava.net/elven/comments/133964.html</wfw:comment><comments>http://www.blogjava.net/elven/archive/2007/08/02/133964.html#Feedback</comments><slash:comments>3</slash:comments><wfw:commentRss>http://www.blogjava.net/elven/comments/commentRss/133964.html</wfw:commentRss><trackback:ping>http://www.blogjava.net/elven/services/trackbacks/133964.html</trackback:ping><description><![CDATA[我在JSP中处理一个if-else语句的时候发现一个奇怪的问题：<br>假设我有一个String型的变量str，它可以等于两个值a和b。现在我想这样处理：如果str=a，就显示字符串&#8220;str现在等于a&#8221;，如果str=b，就显示字符串&#8220;str现在等于b&#8221;。我开始是这样做的：<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>String&nbsp;str</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">""</span><span style="COLOR: #000000">;<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top></span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img id=Codehighlighter1_33_48_Open_Image onclick="this.style.display='none'; Codehighlighter1_33_48_Open_Text.style.display='none'; Codehighlighter1_33_48_Closed_Image.style.display='inline'; Codehighlighter1_33_48_Closed_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockStart.gif" align=top><img id=Codehighlighter1_33_48_Closed_Image style="DISPLAY: none" onclick="this.style.display='none'; Codehighlighter1_33_48_Closed_Text.style.display='none'; Codehighlighter1_33_48_Open_Image.style.display='inline'; Codehighlighter1_33_48_Open_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ContractedBlock.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(str</span><span style="COLOR: #000000">=="</span><span style="COLOR: #000000">a")</span><span id=Codehighlighter1_33_48_Closed_Text style="BORDER-RIGHT: #808080 1px solid; BORDER-TOP: #808080 1px solid; DISPLAY: none; BORDER-LEFT: #808080 1px solid; BORDER-BOTTOM: #808080 1px solid; BACKGROUND-COLOR: #ffffff"><img src="http://www.blogjava.net/Images/dot.gif"></span><span id=Codehighlighter1_33_48_Open_Text><span style="COLOR: #000000">{</span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/InBlock.gif" align=top>str现在等于a<br><img id=Codehighlighter1_64_79_Open_Image onclick="this.style.display='none'; Codehighlighter1_64_79_Open_Text.style.display='none'; Codehighlighter1_64_79_Closed_Image.style.display='inline'; Codehighlighter1_64_79_Closed_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockStart.gif" align=top><img id=Codehighlighter1_64_79_Closed_Image style="DISPLAY: none" onclick="this.style.display='none'; Codehighlighter1_64_79_Closed_Text.style.display='none'; Codehighlighter1_64_79_Open_Image.style.display='inline'; Codehighlighter1_64_79_Open_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ContractedBlock.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000">}</span></span><span style="COLOR: #0000ff">else</span><span style="COLOR: #000000">&nbsp;</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(str</span><span style="COLOR: #000000">=="</span><span style="COLOR: #000000">b")</span><span id=Codehighlighter1_64_79_Closed_Text style="BORDER-RIGHT: #808080 1px solid; BORDER-TOP: #808080 1px solid; DISPLAY: none; BORDER-LEFT: #808080 1px solid; BORDER-BOTTOM: #808080 1px solid; BACKGROUND-COLOR: #ffffff"><img src="http://www.blogjava.net/Images/dot.gif"></span><span id=Codehighlighter1_64_79_Open_Text><span style="COLOR: #000000">{</span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/InBlock.gif" align=top>str现在等于b<br><img src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockEnd.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000">}</span></span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top></span></div>
但是这样做，不管str=a还是str=b，字符串始终显示不出来。于是我用了另一种方法：<br>
<div style="BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 5px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 4px; FONT-SIZE: 13px; PADDING-BOTTOM: 4px; BORDER-LEFT: #cccccc 1px solid; WIDTH: 98%; WORD-BREAK: break-all; PADDING-TOP: 4px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #eeeeee"><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top>String&nbsp;str</span><span style="COLOR: #000000">=</span><span style="COLOR: #000000">""</span><span style="COLOR: #000000">;<br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top></span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img id=Codehighlighter1_33_48_Open_Image onclick="this.style.display='none'; Codehighlighter1_33_48_Open_Text.style.display='none'; Codehighlighter1_33_48_Closed_Image.style.display='inline'; Codehighlighter1_33_48_Closed_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockStart.gif" align=top><img id=Codehighlighter1_33_48_Closed_Image style="DISPLAY: none" onclick="this.style.display='none'; Codehighlighter1_33_48_Closed_Text.style.display='none'; Codehighlighter1_33_48_Open_Image.style.display='inline'; Codehighlighter1_33_48_Open_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ContractedBlock.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #0000ff">if</span><span style="COLOR: #000000">(str</span><span style="COLOR: #000000">=="</span><span style="COLOR: #000000">a")</span><span id=Codehighlighter1_33_48_Closed_Text style="BORDER-RIGHT: #808080 1px solid; BORDER-TOP: #808080 1px solid; DISPLAY: none; BORDER-LEFT: #808080 1px solid; BORDER-BOTTOM: #808080 1px solid; BACKGROUND-COLOR: #ffffff"><img src="http://www.blogjava.net/Images/dot.gif"></span><span id=Codehighlighter1_33_48_Open_Text><span style="COLOR: #000000">{</span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/InBlock.gif" align=top>str现在等于a<br><img id=Codehighlighter1_64_79_Open_Image onclick="this.style.display='none'; Codehighlighter1_64_79_Open_Text.style.display='none'; Codehighlighter1_64_79_Closed_Image.style.display='inline'; Codehighlighter1_64_79_Closed_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockStart.gif" align=top><img id=Codehighlighter1_64_79_Closed_Image style="DISPLAY: none" onclick="this.style.display='none'; Codehighlighter1_64_79_Closed_Text.style.display='none'; Codehighlighter1_64_79_Open_Image.style.display='inline'; Codehighlighter1_64_79_Open_Text.style.display='inline';" src="http://www.blogjava.net/Images/OutliningIndicators/ContractedBlock.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000">}</span></span><span style="COLOR: #0000ff">else</span><span style="COLOR: #000000">&nbsp;</span><span id=Codehighlighter1_64_79_Closed_Text style="BORDER-RIGHT: #808080 1px solid; BORDER-TOP: #808080 1px solid; DISPLAY: none; BORDER-LEFT: #808080 1px solid; BORDER-BOTTOM: #808080 1px solid; BACKGROUND-COLOR: #ffffff"><img src="http://www.blogjava.net/Images/dot.gif"></span><span id=Codehighlighter1_64_79_Open_Text><span style="COLOR: #000000">{</span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/InBlock.gif" align=top>str现在等于b<br><img src="http://www.blogjava.net/Images/OutliningIndicators/ExpandedBlockEnd.gif" align=top></span><span style="COLOR: #000000">&lt;%</span><span style="COLOR: #000000">}</span></span><span style="COLOR: #000000">%&gt;</span><span style="COLOR: #000000"><br><img src="http://www.blogjava.net/Images/OutliningIndicators/None.gif" align=top></span></div>
这样，就可以得到正确结果。<br>但是问题是，这样就只能处理str只取两个值的情况，如果str还有其他值的话，只有把它当成非a来处理了。<br>请教大家：我觉得第一种处理方法中逻辑上也没什么错误，跟第一种方法在逻辑上的意义也是相同的，但是为什么，第一种方法就显示不出来，而第二种就可以显示出来呢？<br>是不是因为，if-else必须配对使用，而第一种方法中只用了if-else if，后面这个if没有else配对的原因？<br>请大家在路过的时候留下来帮小弟解决这个问题，万分感激！ 
<img src ="http://www.blogjava.net/elven/aggbug/133964.html" width = "1" height = "1" /><br><br><div align=right><a style="text-decoration:none;" href="http://www.blogjava.net/elven/" target="_blank">Elven</a> 2007-08-02 11:52 <a href="http://www.blogjava.net/elven/archive/2007/08/02/133964.html#Feedback" target="_blank" style="text-decoration:none;">发表评论</a></div>]]></description></item></channel></rss>