servlet +mysql 出现下面异常,该异常什么意思?如何解决
java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2928)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:771)
    at com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3649)
    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1176)
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:2558)
    at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:185)
    at CreateDBServlet.doGet(CreateDBServlet.java:35)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:228)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:216)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:634)
    at org.apache.tomcat.(JIoEndpoint.java:445)
    at java.lang.Thread.run(Thread.java:619)