tomcat在ROOT下面部署问题

[guosong2046]

我在tomcat下部署我的web项目，不把它当成ROOT时运行正常一点问题都没有，当把它改为ROOT（把以前的ROOT删掉和清空都做过）直接用localhost:8080访问就会报一个“String index out of range: -1”的错误，另外我还试试了把tomcat中的在server.xml中修改为默认为我项目，可是还是报同样的错误，这个可真奇怪了，麻烦大侠们帮着思考一下，以下是log：
严重: Servlet.service() for servlet category threw exception
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
at java.lang.String.substring(String.java:1938)
at java.lang.String.substring(String.java:1905)
at com.filter.CookieFilter.seecookie(CookieFilter.java:47)
at com.filter.CookieFilter.doFilter(CookieFilter.java:29)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.filter.PathFilter.doFilter(PathFilter.java:38)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.filter.LimitFilter.doFilter(LimitFilter.java:28)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.filter.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:24)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:879)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:617)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1760)
at java.lang.Thread.run(Thread.java:619)