可能原因： tuckey.org 无法正常访问 ，urlrewrite 配置 网络 dtd 无法下载 。。
先把 urlrewrite 日志 配置好：
<filter> <filter-name>UrlRewriteFilter</filter-name> <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class> <init-param> <param-name>logLevel</param-name> <param-value>log4j</param-value> </init-param> </filter>
log4j 是使用 log4j 日志配置的 意思
#Created by JInto - www.guh-software.de #Thu Feb 09 10:05:48 CST 2012 log4j.additivity.crawl=false log4j.appender.crawllog=org.apache.log4j.DailyRollingFileAppender log4j.appender.crawllog.Append=true log4j.appender.crawllog.DatePattern='_'yyyy-MM-dd'.log' //根据名字 判断文件产生的时间。例是 每天产生一个日志文件 log4j.appender.crawllog.File=D:/apache-tomcat-6.0.26/fis_logs/crawl.out log4j.appender.crawllog.Threshold=info log4j.appender.crawllog.layout=org.apache.log4j.PatternLayout log4j.appender.crawllog.layout.ConversionPattern=[%p] %d (%F:%L) - %m%n log4j.appender.log=org.apache.log4j.DailyRollingFileAppender log4j.appender.log.Append=true log4j.appender.log.DatePattern='_'yyyy-MM-dd'.log' log4j.appender.log.File=D:/apache-tomcat-6.0.26/fis_logs/logs.out log4j.appender.log.Threshold=debug log4j.appender.log.layout=org.apache.log4j.PatternLayout log4j.appender.log.layout.ConversionPattern=[%p] %d (%F:%L) - %m%n log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.Target=System.out log4j.appender.stdout.Threshold=debug log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=[%p] %d (%F:%L) - %m%n log4j.logger.com.opensymphony=error log4j.logger.crawl=error,crawllog log4j.logger.noModule=FATAL log4j.logger.org.apache.struts2=error log4j.rootLogger=error,log,stdout
重启多次 会发现有时报如下错误：
[ERROR] 2014-12-18 17:33:51,340 (Log.java:400) - Exception loading conf tuckey.org java.net.UnknownHostException: tuckey.org at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:195) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) at java.net.Socket.connect(Socket.java:529) at java.net.Socket.connect(Socket.java:478) at sun.net.NetworkClient.doConnect(NetworkClient.java:163) at sun.net.www.http.HttpClient.openServer(HttpClient.java:394) at sun.net.www.http.HttpClient.openServer(HttpClient.java:529) at sun.net.www.http.HttpClient.<init>(HttpClient.jav a:234) at sun.net.www.http.HttpClient.New(HttpClient.java:306) at sun.net.www.http.HttpClient.New(HttpClient.java:323) at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:970) at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:911) at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:837) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1172) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.setupCurrentEntity(XMLEntityManager.java:677) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startEntity(XMLEntityManager.java:1315) at com.sun.org.apache.xerces.internal.impl.XMLEntityManager.startDTDEntity(XMLEntityManager.java:1283) at com.sun.org.apache.xerces.internal.impl.XMLDTDScannerImpl.setInputSource(XMLDTDScannerImpl.java:284) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.dispatch(XMLDocumentScannerImpl.java:1194) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$DTDDriver.next(XMLDocumentScannerImpl.java:1098) at com.sun.org.apache.xerces.internal.impl.XMLDocu g.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4650) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5306) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1560) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303) at java.util.concurrent.FutureTask.run(FutureTask.java:139) at java.util.concurrent.ThreadPoolExecutor$Worker.run Task(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:909) at java.lang.Thread.run(Thread.java:662) [ERROR] 2014-12-18 17:33:51,343 (Log.java:381) - Conf failed to load mentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:1003) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Conf iguration.java:737) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:121) at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:235) at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:285) at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:153) at org.tuckey.web.filters.urlrewrite.Conf.loadDom(Conf.java:206) at org.tuckey.web.filters.urlrewrite.Conf.<init>(Conf.java:129) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.loadUrlRewriterLocal(UrlRewriteFilter.java: 282) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.loadUrlRewriter(UrlRewriteFilter.java:259) at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.init(UrlRewriteFilter.java:250) at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:277) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260) at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:382) at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:104) at or
解决：1. 系统配置了 访问白名单 ，而 tuckey.org 不在白名单
2. 架包为3.2 而 urlrewrite.xml 文件引入的docment dtd 为 其他版本