Could not create connection to database server

480
10 марта 2018, 16:58

Подскажите пожалуйста в чем проблема?

import java.sql.*;
public class untitled1 {
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String URL = "jdbc:mysql://localhost:3306/Connection?autoReconnect=true&useSSL=false";
    static final String NAME = "root";
    static final String PASS = "pass";
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        Connection connect = null;
        Statement statement = null;
        System.out.println("Registering JDBC driver...");
        Class.forName(JDBC_DRIVER);
        System.out.println("Creating database connection...");
        connect = DriverManager.getConnection(URL,NAME,PASS);
        System.out.println("Executing statement...");
        statement = connect.createStatement();
        String sql;
        sql = "SELECT city, target, sales FROM offices";
        ResultSet resultSet = statement.executeQuery(sql);
        while(resultSet.next()){
            String city = resultSet.getString("city");
            Double target = resultSet.getDouble("target");
            Double sales = resultSet.getDouble("sales");
            System.out.println(city);
            System.out.println(target);
            System.out.println(sales);
        }
        resultSet.close();
        statement.close();
        connect.close();
    }
}

.

Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488)
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:919)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2094)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2019)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:386)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:678)
at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:229)
at untitled1.main(untitled1.java:16)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown database 'Connection'
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:488)
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:3973)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:873)
at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1710)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188)
at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2035)
Answer 1

В ошибке написано, что у вас нет базы данных Connection, к которой вы пытаетесь подключиться.

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