如何通过Java在指定端口上启动Derby Server

Question

我试图测试Derby示例源代码。 不幸的是，它失败了： 无法连接Derby数据库：连接被拒绝

有人告诉我我还没有启动服务器。 官方教程：

1. 不启动任何服务器。在C:\\Apache\\db-derby-10.4.1.3-bin\\lib> java -jar derbyrun.jar server start后，我没有任何反馈，只是空行显示而derbyrun.jar结束了。

   2. 没有显示如何在指定端口上创建服务器

我的问题是：如何在指定的端口上启动服务器，以便发布的代码起作用：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSetMetaData;


public class Restaurants
{
    private static String dbURL = "jdbc:derby://localhost:1526/myDB;create=true;user=me;password=mine";
    private static String tableName = "restaurants";
    // jdbc Connection
    private static Connection conn = null;
    private static Statement stmt = null;

    public static void main(String[] args)
    {
        createConnection();
        insertRestaurants(5, "LaVals", "Berkeley");
        selectRestaurants();
        shutdown();
    }

    private static void createConnection()
    {
        try
        {
            Class.forName("org.apache.derby.jdbc.ClientDriver").newInstance();
            //Get a connection
            conn = DriverManager.getConnection(dbURL); 
        }
        catch (Exception except)
        {
            except.printStackTrace();
        }
    }

    private static void insertRestaurants(int id, String restName, String cityName)
    {
        try
        {
            stmt = conn.createStatement();
            stmt.execute("insert into " + tableName + " values (" +
                    id + ",'" + restName + "','" + cityName +"')");
            stmt.close();
        }
        catch (SQLException sqlExcept)
        {
            sqlExcept.printStackTrace();
        }
    }

    private static void selectRestaurants()
    {
        try
        {
            stmt = conn.createStatement();
            ResultSet results = stmt.executeQuery("select * from " + tableName);
            ResultSetMetaData rsmd = results.getMetaData();
            int numberCols = rsmd.getColumnCount();
            for (int i=1; i<=numberCols; i++)
            {
                //print Column Names
                System.out.print(rsmd.getColumnLabel(i)+"\t\t");  
            }

            System.out.println("\n-------------------------------------------------");

            while(results.next())
            {
                int id = results.getInt(1);
                String restName = results.getString(2);
                String cityName = results.getString(3);
                System.out.println(id + "\t\t" + restName + "\t\t" + cityName);
            }
            results.close();
            stmt.close();
        }
        catch (SQLException sqlExcept)
        {
            sqlExcept.printStackTrace();
        }
    }

    private static void shutdown()
    {
        try
        {
            if (stmt != null)
            {
                stmt.close();
            }
            if (conn != null)
            {
                DriverManager.getConnection(dbURL + ";shutdown=true");
                conn.close();
            }           
        }
        catch (SQLException sqlExcept)
        {

        }

    }
}

Answer 1

设置端口号

默认情况下，使用网络服务器的Derby侦听TCP / IP端口号1527。如果要使用其他端口号，则可以在启动网络服务器时在命令行上指定它。 例如：

java org.apache.derby.drda.NetworkServerControl start -p 1088

但是，最好使用以下任何一种方法来指定端口号

1. Change the startNetworkServer.bat or startNetworkServer.ksh scripts
2. Use the derby.drda.portNumber property in derby.properties

请参阅：

https://db.apache.org/derby/docs/10.5/adminguide/tadminappssettingportnumbers.html