数据库登入出错请求帮助
org.apache.tomcat.dbcp.dbcp.SQLNestedException:   Cannot   create   JDBC   driver   of   class   ' '   for   connect   URL   'null '
at   org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:780)
at   org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:540)
at   com.nit.leidp.struts.db.DatabaseConn.getConnection(DatabaseConn.java:25)
at   com.nit.leidp.struts.model.login.check(login.java:28)
at   com.nit.leidp.struts.action.LoginAction.execute(LoginAction.java:102)
at   org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:419)
at   org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:224)
at   org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
at   com.nit.leidp.struts.db.InitServerlet.process(InitServerlet.java:79)
at   org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at   javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
at   javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at   filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:41)
at   org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at   org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at   org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at   org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at   org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at   org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at   org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at   org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at   org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
at   org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:667)
at   org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
at   org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
at   org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
at   java.lang.Thread.run(Thread.java:595)
Caused   by:   java.sql.SQLException:   No   suitable   driver
at   java.sql.DriverManager.getDriver(DriverManager.java:243)
at   org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:773)
...   28   more

------解决方案--------------------
看错误好像是类还没实力化,还是NULL就调用他的函数了.