解决方法
You could try adding a user specified catalog contribution to Eclipse. Under Window->Preferences->XML->XML Catalog select User Specified Entries and then the Add button. You can then add the details for the schema (you could copy the file locally in case of dropped connection). Eclipse will then have access to the schema during validation.
例子
https://stackoverflow.com/questions/901242/why-cant-eclipse-resolve-the-spring-dwr-schema