数据库连接不上

程序运行报404，数据库名和表名都是user，tomcat只有一条报警内容

tomcat：

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Server version:        Apache Tomcat/7.0.94

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Server built:          Apr 10 2019 16:56:40 UTC

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Server number:         7.0.94.0

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: OS Name:               Windows 10

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: OS Version:            10.0

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Architecture:          amd64

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Java Home:             D:\java\jdk8\jre

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: JVM Version:           1.8.0_121-b13

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: JVM Vendor:            Oracle Corporation

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: CATALINA_BASE:         D:\java\exercise-ECLIPSE\.metadata\.plugins\org.eclipse.wst.server.core\tmp0

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: CATALINA_HOME:         D:\java\Tomcat\apache-tomcat-7.0.94

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Command line argument: -Dcatalina.base=D:\java\exercise-ECLIPSE\.metadata\.plugins\org.eclipse.wst.server.core\tmp0

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Command line argument: -Dcatalina.home=D:\java\Tomcat\apache-tomcat-7.0.94

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Command line argument: -Dwtp.deploy=D:\java\exercise-ECLIPSE\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Command line argument: -Djava.endorsed.dirs=D:\java\Tomcat\apache-tomcat-7.0.94\endorsed

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.VersionLoggerListener log

信息: Command line argument: -Dfile.encoding=GBK

一月 27, 2020 7:39:21 下午 org.apache.catalina.core.AprLifecycleListener lifecycleEvent

信息: Loaded APR based Apache Tomcat Native library 1.2.21 using APR version 1.6.5.

一月 27, 2020 7:39:21 下午 org.apache.catalina.core.AprLifecycleListener lifecycleEvent

信息: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].

一月 27, 2020 7:39:21 下午 org.apache.catalina.core.AprLifecycleListener initializeSSL

信息: OpenSSL successfully initialized (OpenSSL 1.1.1a  20 Nov 2018)

一月 27, 2020 7:39:21 下午 org.apache.coyote.AbstractProtocol init

信息: Initializing ProtocolHandler ["http-apr-8080"]

一月 27, 2020 7:39:21 下午 org.apache.coyote.AbstractProtocol init

信息: Initializing ProtocolHandler ["ajp-apr-8009"]

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.Catalina load

信息: Initialization processed in 623 ms

一月 27, 2020 7:39:21 下午 org.apache.catalina.core.StandardService startInternal

信息: Starting service Catalina

一月 27, 2020 7:39:21 下午 org.apache.catalina.core.StandardEngine startInternal

信息: Starting Servlet Engine: Apache Tomcat/7.0.94

一月 27, 2020 7:39:21 下午 org.apache.catalina.startup.TldConfig execute

信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

一月 27, 2020 7:39:22 下午 org.apache.catalina.util.SessionIdGeneratorBase createSecureRandom

警告: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [397] milliseconds.

一月 27, 2020 7:39:22 下午 org.apache.catalina.startup.TldConfig execute

信息: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

一月 27, 2020 7:39:22 下午 org.apache.coyote.AbstractProtocol start

信息: Starting ProtocolHandler ["http-apr-8080"]

一月 27, 2020 7:39:22 下午 org.apache.coyote.AbstractProtocol start

信息: Starting ProtocolHandler ["ajp-apr-8009"]

一月 27, 2020 7:39:22 下午 org.apache.catalina.startup.Catalina start

信息: Server startup in 1225 ms

程序：

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import com.mysql.jdbc.Driver;

public class JDBCDEMO1 {

public void demo1() {

try {

DriverManager.registerDriver(new Driver());

Connection connection= DriverManager.getConnection("jdbc:mysql://localhost:3306/user", "root", "123456tian");

String sql="select * from user";

Statement stmt = connection.createStatement();

        ResultSet resultset = stmt.executeQuery(sql);

        while(resultset.next()) {

        int id =resultset.getInt("uid");

        String username = resultset.getString("username");

        String password = resultset.getString("password");

        String name = resultset.getString("name");

        System.out.println(id+" "+username+" "+password+" "+name);

        }

        resultset.close();

        stmt.close();

        connection.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}