java - 连接到 Amazon RDS 时被阻止

Question

我最近在 Amazon RDS 上部署了一个数据库实例，我正试图掌握它的窍门。按照文档中的说明进行操作后，我尝试连接到该数据库实例，但由于某种原因，我显示服务器版本的简单程序在连接上挂起。

这是我的代码:

import java.sql.*;

public class AWSTest {

    public static void main(String[] args) {
        System.out.println(getVersion());
    }

    public static String getVersion() {
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            System.out.println("Driver Error: " + e.getMessage());
            return VERSION_NOT_FOUND;
        }

        System.out.println(CONNECTING_MESSAGE);
        try (Connection con = DriverManager.getConnection(DB_URL,
                USER,
                PASS);
                Statement stmt = con.createStatement();) {

            System.out.println("Getting server version...");
            try (ResultSet rs = stmt.executeQuery(VERSION_QUERY);) {
                rs.next();
                return rs.getString(1);
            }
        } catch (SQLException se) {
            System.out.println("SQL Error: " + se.getErrorCode() + " "
                    + se.getMessage());
            return VERSION_NOT_FOUND;
        }
    }


    static final String DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://**************.*******."
            + "*******.rds.amazonaws.com:3306";

    private static final String VERSION_QUERY = "Select VERSION()";
    static final String USER = "*******";
    static final String PASS = "*******";
    private static final String VERSION_NOT_FOUND = "Version was not found";

    public static final String GETTING_DRIVER_MESSAGE = "Getting driver...";
    public static final String CONNECTING_MESSAGE = "Connecting to server...";
}

我的程序卡在 Connection con = DriverManager.getConnection(DB_URL, USER, PASS); 行，我的主要问题是它甚至没有抛出异常，它只是停留在那里。

USER、PASS 和 DB_URL 绝对正确。

Answer 1

听起来您的 IP/端口被阻止/丢弃了。这通常是连接不执行任何操作(与被拒绝或登录失败相反)的情况。确保您的安全组设置正确。 http://aws.amazon.com/rds/faqs/#31