An exception occurred processing JSP page /manager/logon.jsp at line 21

Question

我是新手，运行jsp页面总报错，请问是怎么回事吖
type Exception reportmessage An exception occurred processing JSP page /manager/logon.jsp at line 21description The server encountered an internal error that prevented it from fulfilling this request.exceptionorg.apache.jasper.JasperException: An exception occurred processing JSP page /manager/logon.jsp at line 2118:  Class.forName("com.mysql.jdbc.Driver");
19:  //String driver="jdbc:mysql://localhost/DB";
20:  //Connection conn=DriverManager.getConnection("jdbc:mysql://localhost/DB","root","19910510");
21:  Connection Con=DriverManager.getConnection("jdbc:mysql://localhost/DB","root","19910510");
22:  Statement stmt=Con.createStatement();
23:  boolean a;
24:  String select;

Answer 1

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:455)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)root causejavax.servlet.ServletException: java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:912)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:841)
org.apache.jsp.manager.logon_jsp._jspService(logon_jsp.java:149)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

Answer 2

root causejava.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1056)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3376)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3308)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:894)
com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3808)
com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1256)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2032)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:729)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
java.lang.reflect.Constructor.newInstance(Unknown Source)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:283)
java.sql.DriverManager.getConnection(Unknown Source)
java.sql.DriverManager.getConnection(Unknown Source)
org.apache.jsp.manager.logon_jsp._jspService(logon_jsp.java:84)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)