刚开始只开Myeclipse 这时候启动tomcat一切都正常 然后启动Eclipse （Eclipse导入Myeclipse的项目进行修改） 修改之后 用Myeclipse运行下 看到修改内容没有被改变 然后重启了下tomcat 结果页面是HTTP Status 404 Tomcat启动报错是：
严重: Exception starting filter CocallFilter
java.lang.Error: Unresolved compilation problems:
The type javax.servlet.http.HttpServletRequest cannot be resolved. It is indirectly referenced from required .class files
The type javax.servlet.http.HttpServletResponse cannot be resolved. It is indirectly referenced from required .class files
The import javax.servlet.Filter cannot be resolved
The import javax.servlet.FilterChain cannot be resolved
The import javax.servlet.FilterConfig cannot be resolved
The import javax.servlet.ServletException cannot be resolved
The import javax.servlet.ServletRequest cannot be resolved
The import javax.servlet.ServletResponse cannot be resolved
The import javax.servlet.http.HttpServletRequest cannot be resolved
The import javax.servlet.http.HttpServletResponse cannot be resolved
Filter cannot be resolved to a type
FilterConfig cannot be resolved to a type
ServletException cannot be resolved to a type
ServletRequest cannot be resolved to a type
ServletResponse cannot be resolved to a type
FilterChain cannot be resolved to a type
ServletException cannot be resolved to a type
HttpServletRequest cannot be resolved to a type
HttpServletRequest cannot be resolved to a type
HttpServletResponse cannot be resolved to a type
HttpServletResponse cannot be resolved to a type
at com.thunisoft.cocall.CocallFilter.(CocallFilter.java:1)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:501)
at java.lang.Class.newInstance0(Class.java:350)
at java.lang.Class.newInstance(Class.java:303)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:115)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4001)
（后面还有 要超出字数限制了）
即使关掉eclipse 重新启动一次myeclipse也依旧如此 请问改怎么解决呀？
