Google Cloud SQL - 无法连接到 MySQL 数据库

Question

我正在尝试使用 Java 和 HikariConfig API（如 Google 教程中所示）连接到托管在 Google Cloud Platform 上的 MySQL 数据库。我正在 Eclipse 中构建我的代码，但尽管做了我能想到的一切，但我的连接不起作用。我能够使用 Mysql 工作台（使用公共 api）和使用 localhost（代替 Google App Engine）连接到同一个数据库。我想我的项目中缺少一个 jar 文件。我正在添加我的 jar 库的代码和屏幕截图。

我得到的错误如下：

java.lang.AbstractMethodError: Method com/google/cloud/sql/mysql/SocketFactory.connect(Ljava/lang/String;ILcom/mysql/cj/conf/PropertySet;I)Ljava/io/Closeable; is abstract
at com.google.cloud.sql.mysql.SocketFactory.connect (SocketFactory.java)
at com.mysql.cj.protocol.a.NativeSocketConnection.connect (NativeSocketConnection.java:65)
at com.mysql.cj.NativeSession.connect (NativeSession.java:152)
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly (ConnectionImpl.java:955)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO (ConnectionImpl.java:825)
at com.mysql.cj.jdbc.ConnectionImpl.<init> (ConnectionImpl.java:455)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance (ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect (NonRegisteringDriver.java:199)
at com.zaxxer.hikari.util.DriverDataSource.getConnection (DriverDataSource.java:117)
at com.zaxxer.hikari.util.DriverDataSource.getConnection (DriverDataSource.java:123)
at com.zaxxer.hikari.pool.PoolBase.newConnection (PoolBase.java:365)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry (PoolBase.java:194)
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry (HikariPool.java:460)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast (HikariPool.java:534)
at com.zaxxer.hikari.pool.HikariPool.<init> (HikariPool.java:115)
at com.zaxxer.hikari.HikariDataSource.<init> (HikariDataSource.java:81)
at com.x.d3sols.web.ConnectionPoolContextListener.createConnectionPool (ConnectionPoolContextListener.java:51)
at com.x.d3sols.web.ConnectionPoolContextListener.contextInitialized (ConnectionPoolContextListener.java:71)
at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized (ContextHandler.java:843)
at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized (ServletContextHandler.java:533)
at org.eclipse.jetty.server.handler.ContextHandler.startContext (ContextHandler.java:816)
at org.eclipse.jetty.servlet.ServletContextHandler.startContext (ServletContextHandler.java:345)
at org.eclipse.jetty.webapp.WebAppContext.startWebapp (WebAppContext.java:1406)
at com.google.apphosting.runtime.jetty9.AppEngineWebAppContext.startWebapp (AppEngineWebAppContext.java:175)
at org.eclipse.jetty.webapp.WebAppContext.startContext (WebAppContext.java:1368)
at org.eclipse.jetty.server.handler.ContextHandler.doStart (ContextHandler.java:778)
at org.eclipse.jetty.servlet.ServletContextHandler.doStart (ServletContextHandler.java:262)
at org.eclipse.jetty.webapp.WebAppContext.doStart (WebAppContext.java:522)
at com.google.apphosting.runtime.jetty9.AppEngineWebAppContext.doStart (AppEngineWebAppContext.java:120)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start (AbstractLifeCycle.java:68)
at com.google.apphosting.runtime.jetty9.AppVersionHandlerMap.createHandler (AppVersionHandlerMap.java:240)
at com.google.apphosting.runtime.jetty9.AppVersionHandlerMap.getHandler (AppVersionHandlerMap.java:178)
at com.google.apphosting.runtime.jetty9.JettyServletEngineAdapter.serviceRequest (JettyServletEngineAdapter.java:120)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchServletRequest (JavaRuntime.java:722)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchRequest (JavaRuntime.java:685)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run (JavaRuntime.java:655)
at com.google.apphosting.runtime.JavaRuntime$NullSandboxRequestRunnable.run (JavaRuntime.java:847)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run (ThreadGroupPool.java:270)
at java.lang.Thread.run (Thread.java:748)

这对我来说非常重要，任何帮助都将不胜感激。谢谢:)

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import javax.sql.DataSource;

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

/**
 * Servlet implementation class ConnectionPoolContextListener
 */
@WebListener("Creates a connection pool that is stored in the Servlet's context for later use.")
public class ConnectionPoolContextListener implements ServletContextListener {

    // Saving credentials in environment variables is convenient, but not secure - consider a more
    // secure solution such as https://cloud.google.com/kms/ to help keep secrets safe.
    private static final String DB_USER = "<user>";
    private static final String DB_PASS = "<password>";
    private static final String CLOUD_SQL_CONNECTION_NAME = "<Connection_Name>";
    private static final String DB_NAME = "<DB_Name>";

      private DataSource createConnectionPool() {
            // [START cloud_sql_mysql_servlet_create]
            // The configuration object specifies behaviors for the connection pool.
            HikariConfig config = new HikariConfig();

            //For Localhost - IT WORKS
            /*String url = "jdbc:mysql://<IP_Address>/<DB_NAME>";
            config.setJdbcUrl(url);
            config.setUsername(DB_USER); 
            config.setPassword(DB_PASS);
            config.setDriverClassName("com.mysql.jdbc.Driver");
            config.addDataSourceProperty("useSSL", "false");*/

            //For APP ENGINE - IT DOESNT WORKS
            String url = "jdbc:mysql://google/<DB_NAME>";
            config.setJdbcUrl(url);
            config.setUsername(DB_USER);
            config.setPassword(DB_PASS);
            config.addDataSourceProperty("socketFactory", "com.google.cloud.sql.mysql.SocketFactory");
            config.addDataSourceProperty("cloudSqlInstance", CLOUD_SQL_CONNECTION_NAME);
            config.addDataSourceProperty("useSSL", "false");
            config.setDriverClassName("com.mysql.jdbc.Driver");

            config.setMaximumPoolSize(5);
            config.setMinimumIdle(5);
            config.setConnectionTimeout(60000); 
            config.setIdleTimeout(600000); 
            config.setMaxLifetime(1800000); // 30 minutes
            DataSource pool = new HikariDataSource(config);
            return pool;
          }


      @Override
      public void contextDestroyed(ServletContextEvent event) {
        // This function is called when the Servlet is destroyed.
        HikariDataSource pool = (HikariDataSource) event.getServletContext().getAttribute("my-pool");
        if (pool != null) {
          pool.close();
        }
      }

      @Override
      public void contextInitialized(ServletContextEvent event) {
        // This function is called when the application starts and will safely create a connection pool
        // that can be used to connect to.
        DataSource pool = (DataSource) event.getServletContext().getAttribute("my-pool");
        if (pool == null) {
          pool = createConnectionPool();
          event.getServletContext().setAttribute("my-pool", pool);
        }
      }
}

Here is the screenshot of my folder where I've added missing libraries that I could think of

Answer 1

一旦我遇到同样的问题（我知道它有多痛苦），并且我没有太多的 java 经验，但我可以告诉你我如何将 cloud-sql 与 app-engine 连接起来

注意这两点：

如果您想将 cloud-sql 与 app-engine 连接，则连接必须通过 socket 否则无法连接，如果您想从localhost 到 cloud-sql 应该是通过tcp。在最后一种情况下，您的公共 ip 需要添加到connections 部分中的授权网络。

据我所知，您的操作还可以，但您可以尝试按照文档中的建议格式化网址：

HikariConfig config = new HikariConfig();
config.setJdbcUrl(String.format("jdbc:mysql:///%s", DB_NAME));

最后一件事您需要确保CLOUD_SQL_CONNECTION_NAME 的格式如下：

CLOUD_SQL_CONNECTION_NAME = 'project-id:region:instance-id'

// You can get this information from the overview page in google cloud console - sql.

有关更多信息，您可以查看这两个链接 Google docs 和 Java example

希望对你有帮助。

Answer 2

在 cmets 的帮助下，我终于设法解决了这个问题。显然，我添加的 appengine-web.xml 文件中缺少一个字符串，它得到了修复。我还替换了类路径中的一些 jar 文件。

appengine-web.xml中要添加的字符串是：

<use-google-connector-j>true</use-google-connector-j> 

您的库将如下所示：

请注意您使用的所有库的版本，我使用的是 v8。除 Gson 之外的所有库都是必需的。