我个人来说，对于java出现的异常来说，最怕的就是这种各个软件各个版本不兼容的问题，目前我也没有好的办法，只能靠积累，然后就是遇到什么再说了，希望有大神可以支招
问了度娘，其实也很好解决，主要是myeclipse对于Html，js等的编辑要求太敏感，具体的我也不是很清楚。
解决方法： 如下图：在myeclipse的window-preferences:
把build的那一列的勾都去掉，就可以了。 这样好像是治标不治本，但是其实项目本身是没错的，这样比较方便运行测试，至于有什么严重的后果，无从得知，现在一切正常
DescriptionResourcePathLocationType The project was not built since its build path is incomplete. Cannot find the class。。。。。
又求助度娘，发现了下面这篇文章： http://www.cnblogs.com/czx1/p/6961307.html
原来是jdk版本不兼容，于是，我在项目右击-buildpath-configure bulid path:
项目不再报错ok。
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: Invalid authorization specification, message from server: “Access denied for user ‘root’@’localhost’ (using password: YES)” org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:523) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:421) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224) com.REP.processor.EncodingProcessor.process(EncodingProcessor.java:16) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194) org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432) javax.servlet.http.HttpServlet.service(HttpServlet.java:637) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) root cause
org.springframework.transaction.CannotCreateTransactionException: Could not open JDBC Connection for transaction; nested exception is java.sql.SQLException: Invalid authorization specification, message from server: “Access denied for user ‘root’@’localhost’ (using password: YES)” org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:219) org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:283) org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:226) org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:89) org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:170) org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:176) $Proxy1.repast(Unknown Source) com.REP.action.EmployeeOperateAction.employeeRepast(EmployeeOperateAction.java:38) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) java.lang.reflect.Method.invoke(Method.java:597) org.apache.struts.actions.DispatchAction.dispatchMethod(DispatchAction.java:274) org.apache.struts.actions.DispatchAction.execute(DispatchAction.java:194) org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224) com.REP.processor.EncodingProcessor.process(EncodingProcessor.java:16) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194) org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432) javax.servlet.http.HttpServlet.service(HttpServlet.java:637) javax.servlet.http.HttpServlet.service(HttpServlet.java:717) root cause
java.sql.SQLException: Invalid authorization specification, message from server: “Access denied for user ‘system’@’localhost’ (using password: YES)”
度娘了一下，都说是用户名密码错了，可是我确定我的是没错的啊，怎么回事呢？找了好久，终于发现，我的一个jdbc配置文件：
本来是打算兼容其他数据库的（我这个电脑同时装了oracle和mysql），结果好像本来应该读mysql的变成读oracle，连用户名都是oracle的，把它删了剩下mysql的后，重启tomcat。ok。
后来发现项目数据源配置的时候也有一些问题，没有及时更新，心累！
以上纯属个人观点和体会 希望这篇文章能对你有所帮助！ 欢迎大家来一起讨论分享干货，或者批评指正！ 更加热切盼望各路大神前辈给些指导和建议！
以后会不定期更新心得和总结，包括学习过程中各种异常和解决办法等等。再见！
