Can't connect to Cloud SQL Database using JDBC through Android Studio

问题

I have a Cloud Sql instance created that is running. I have been trying for a bit now to connect to it through Android Studio and Eclipse and have failed in both places.

package com.example.testapplication3;

import java.sql.*;

public class ConnectToSql {

    public String run()
    {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");

            String instanceConnectionName = "TheActualInstanceName"; 
            String databaseName = "BudgetApp";

            String IP_of_instance = "35.******";
            String username = "root";
            String password = "********";
            String jdbcUrl = String.format("jdbc:mysql://%s/%s?cloudSqlInstance=%s" + 
                    "&socketFactory=com.google.cloud.sql.mysql.SocketFactory&useSSL=false",
                    IP_of_instance, databaseName, instanceConnectionName);

            Connection connection = DriverManager.getConnection(jdbcUrl, username, password);

            Statement stat = connection.createStatement();
            ResultSet res = stat.executeQuery("Select * from users;");
            String result = "";
            while (res.next()) 
            {
                result += (res.getString(1) + " " + res.getString(2) + " " + res.getString(3));
            }

            connection.close();

            return result;
        }
        catch(Exception e)
        {
            System.out.println(e);
            return null;
        }

    }
}

I am continuously getting this error from it:

java.sql.SQLNonTransientConnectionException: Cannot connect to MySQL server on 35.*******:3,306.
    Make sure that there is a MySQL server running on the machine/port you are trying to connect to and that the machine this software is running on is able to connect to this host/port (i.e. not firewalled). Also make sure that the server has not been started with the --skip-networking flag.

What I've done:

Made sure my IP is whitelisted under the Instance Connections tab
Different formatting for the url connection
Made sure the server is up by pinging
Connected by Cloud Shell ONLY
Confirmed port is open on Cloud end

回答1:

You should follow the guide of connecting to Cloud SQL from external applications. You should use the Cloud SQL jdbc socket factory, as I guess you are already using.

From your code I can see just the jdbc url looks a bit strange. Try to change it into this exact format, please :

jdbc:mysql://google/<DATABASE_NAME>?cloudSqlInstance=<INSTANCE_CONNECTION_NAME>&socketFactory=com.google.cloud.sql.mysql.SocketFactory&useSSL=false&user=<MYSQL_USER_NAME>&password=<MYSQL_USER_PASSWORD>

You are missing the "google" part. Hope this will help ! If this does not work it may worth trying to connect through the Cloud SQL proxy as you can see in the first link that I have attached here.

来源：https://stackoverflow.com/questions/58495312/cant-connect-to-cloud-sql-database-using-jdbc-through-android-studio

标签

java

android

android-studio

google-cloud-sql