Question

我正在尝试使用以下常见的MySQL命令将表单数据上传到GoogleCloud MySQL数据库：

try {java.sql.Connection conn=dao.getcon();
        PreparedStatement ps=conn.prepareStatement("insert into register values(?,?,?,?,?,?,?,?)");
    ps.setString(1,"Subhanshu");
    ps.setString(2,"bigu");
    ps.setLong(3,54566522);
    ps.setLong(4,5456662);
    ps.setString(5,"subhanshu");
    ps.setString(6,"hello");
    ps.setString(7,"hello");
    ps.setString(8,"online");
    ps.execute();
    conn.commit();
    flag=1;
    System.out.print("Success");

    }
    catch(Exception e){

    }

但是，数据没有插入数据库中。另一方面，可以很容易地建立连接，如下所示：

    Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
Aug 02, 2018 7:08:00 PM com.google.cloud.sql.mysql.SocketFactory connect
INFO: Connecting to Cloud SQL instance [edu-vitae-211606:asia-south1:edu-vitae1].
Aug 02, 2018 7:08:00 PM com.google.cloud.sql.mysql.SslSocketFactory getInstance
INFO: First Cloud SQL connection, generating RSA key pair.
Aug 02, 2018 7:08:01 PM com.google.cloud.sql.mysql.SslSocketFactory fetchInstanceSslInfo
INFO: Obtaining ephemeral certificate for Cloud SQL instance [edu-vitae-211606:asia-south1:edu-vitae1].
Aug 02, 2018 7:08:03 PM com.google.cloud.sql.mysql.SslSocketFactory createAndConfigureSocket
INFO: Connecting to Cloud SQL instance [edu-vitae-211606:asia-south1:edu-vitae1] on IP [35.200.134.221].

我用来与GoogleCloud数据库建立连接的代码如下：`

 package com.example.dao;

import java.sql.Connection;
import java.sql.DriverManager;

public class dao {
    private static Connection con;
    public static Connection getcon(){
        try{
            String instanceConnectionName = "edu-vitae1";
            String databaseName = "eduvitae";
             String username = <USER>;
             String password = <PASSWORD>;
             Class.forName("com.mysql.jdbc.Driver");
             String jdbcUrl = String.format(
             "jdbc:mysql://google/eduvitae?cloudSqlInstance=edu-vitae-211606:asia-south1:edu-vitae1&socketFactory=com.google.cloud.sql.mysql.SocketFactory&user=<USER>&password=<PASSWORD>&useSSL=false",
             databaseName,
            instanceConnectionName);
            //Connection con=DriverManager.getConnection("jdbc:mysql://google/eduvitae?cloudSqlInstance=edu-vitae-211606:asia-south1:edu-vitae1&socketFactory=com.google.cloud.sql.mysql.SocketFactory&useSSL=false&user=<USER>&password=<PASSWORD>");
             Connection con = DriverManager.getConnection(jdbcUrl, username, password);
             //con=DriverManager.getConnection("jdbc:mysql://localhost:3306/edu",<USER>,<PASSWORD>);
             //String url= String.format("jdbc:mysql://35.200.134.221:3306/edu-vitae-211606:asia-south1:edu-vitae1");
             //Connection con= DriverManager.getConnection(url, <USER>,<PASSWORD>);
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return con;
    }

}

请告诉我如何将表单数据插入Google Cloud Database。 ` 预先谢谢你。

Answer 1

仔细检查我的代码后，我确定了我的问题。在代码中，我在顶部创建了一个全局变量“ private static Connection con;”。但是在try块中，我使用Connection con = DriverManager.getConnection（jdbcUrl，username，password）;创建了另一个局部变量。所以发生的事情是使用了局部变量来建立连接。所以包含了con con变量空连接。我在下面发布解决方案供参考：

   package com.example.dao;

import java.sql.Connection;
import java.sql.DriverManager;

public class dao {
    private static Connection con;
    public static Connection getcon(){
        try{
            String instanceConnectionName = "edu-vitae1";
            String databaseName = "eduvitae";
             String username = <USER>;
             String password = <PASSWORD>;
             Class.forName("com.mysql.jdbc.Driver");
             String jdbcUrl = String.format(
             "jdbc:mysql://google/eduvitae?cloudSqlInstance=edu-vitae-211606:asia-south1:edu-vitae1&socketFactory=com.google.cloud.sql.mysql.SocketFactory&user=<USER>&password=<PASSWORD>;&useSSL=false",
             databaseName,
            instanceConnectionName);
             con = DriverManager.getConnection(jdbcUrl, username, password);
            //Connection con=DriverManager.getConnection("jdbc:mysql://google/eduvitae?cloudSqlInstance=edu-vitae-211606:asia-south1:edu-vitae1&socketFactory=com.google.cloud.sql.mysql.SocketFactory&useSSL=false&user=<USER>&password=<PASSWORD>;");
             //con=DriverManager.getConnection("jdbc:mysql://localhost:3306/edu",<USER>,<PASSWORD>;);
             //String url= String.format("jdbc:mysql://35.200.134.221:3306/edu-vitae-211606:asia-south1:edu-vitae1");
             //Connection con= DriverManager.getConnection(url, <USER>,<PASSWORD>;);
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return con;
    }

}

如何使用Java将表单数据插入GoogleCloud Mysql数据库

1 个答案: