这是loginservlet1的代码。package com.xugencheng.javaweb;import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;public class LoginServlet1 extends HttpServlet{

/**
 * 
 */
private static final long serialVersionUID = 1L; /**
 * 
 */
@Override
protected void doPost(HttpServletRequest req,HttpServletResponse res)
throws ServletException,IOException{
String username = req.getParameter("username");
String password = req.getParameter("password");


Connection connection = null;
PreparedStatement statement = null;
ResultSet resultSet = null;

PrintWriter out = res.getWriter();
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/myfirstsql";
String user = "root";
String password2 = "xgcxgc";

connection = DriverManager.getConnection(url,user,password2);
String sql ="SELECT count(id) FROM testtable WHERE username = ? " + "AND password = ? ";

    statement = connection.prepareStatement(sql);
statement.setString(1, username);
statement.setString(2, password);

resultSet = statement.executeQuery();

if(resultSet.next()) {
int count = resultSet.getInt(1);

if(count>0) {
out.println("Hello:"+username);

}else {
out.println("Sorry:"+username);
}
}

} catch (Exception e) {
e.printStackTrace();
}finally {
try {
     if(resultSet!=null) {
      resultSet.close();

     }
  }catch(SQLException e) {
  e.printStackTrace();
  }
try {
     if(statement!=null) {
      statement.close();

     }
  }catch(SQLException e) {
  e.printStackTrace();
  }
try {
     if(connection!=null) {
      connection.close();

     }
  }catch(SQLException e) {
  e.printStackTrace();
  }
}
}



}这是login.html 的   <!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body><form action ="LoginServlet1" method = "post">
    username:<input type="text" name="username"/>
    password:<input type="password" name="password"/>
    
    <input type="submit" value="Submit"/>
</form></body>
</html>报错:
Fri Apr 06 17:16:30 CST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: FUNCTION mysql.cound does not exist
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:944)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2530)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2683)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2486)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1966)
at com.xugencheng.javaweb.LoginServlet1.doPost(LoginServlet1.java:48)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:407)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:754)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1376)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)