[求助]一个重要的问题,需要帮助

F:\Bjakarta-tomcat-5.0.28\webapps\bbs\WEB-INF\classes\LoginAction.java:20: cannot access bbs.Constants
bad class file: F:\Bjakarta-tomcat-5.0.28\webapps\bbs\WEB-INF\classes\bbs\Constants.class
class file has wrong version 49.0, should be 48.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
DataSource dataSource = (DataSource)context.getAttribute(Constants.DATASOURCE_KEY);
这是我在struts中写的一个类,编译的时候出现这个错误,是版本的问题么啊,谢谢啊,帮我解决一下
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