Question

我正在使用Java设置新的客户端-服务器应用程序，并且必须使用RMI创建服务器。范围太大，我需要数据库。我正在使用基本方法来创建服务器。

这是我的远程接口类

package Connectivity;
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.sql.Connection;

public interface ConnectInterface extends Remote{

    String welcomeBanner() throws RemoteException;

    Connection getDBConnection() throws RemoteException;
    //Just a comment

}

实施类

package Connectivity;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class ServerConnection extends UnicastRemoteObject implements ConnectInterface{

    private static ServerConnection SCInstance;
    private static Connection connection;
    String welcomeBannerText;

    String driver = "com.mysql.jdbc.Driver";
    String url = "jdbc:mysql://localhost:3306/xam_test1";
    String username = "root";
    String password = "";

    protected ServerConnection() throws RemoteException {
        super();
        // TODO Auto-generated constructor stub
    }

    public static ServerConnection getInstance() throws RemoteException {
        if(SCInstance == null) {
            SCInstance = new ServerConnection();
        }
        return SCInstance;
    }

    public Connection getDBConnection() {
        try {
            if (connection == null || connection.isClosed()) {
                Class.forName(driver);
                connection = DriverManager.getConnection(url, username, password);
            }
        } catch (ClassNotFoundException | SQLException e) {
            System.out.println("Error in ServerConnection: " + e);
        }
        return connection;
    }

    @Override
    public String welcomeBanner() throws RemoteException {
        // TODO Auto-generated method stub
        return welcomeBannerText;
    }

}

服务器程序

package Connectivity;
import java.sql.Statement;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.sql.Connection;
import java.sql.ResultSet;

public class StartServer {

    public static void main(String[] args) {

        try {
            int PORT = 1318;

            Registry registry = LocateRegistry.createRegistry(PORT);
            LocateRegistry.getRegistry();
            ServerConnection stub = new ServerConnection();
            stub.welcomeBannerText = "Welcome to X-AM";
            System.out.println("Server is starting");
            registry.rebind("jdbc:mysql://localhost:3306/xam_test1", stub);
            System.out.println("Server is ready");
        } catch (Exception e) {
            System.out.println("Error: " + e.toString());
        }
    }
}

客户端程序（这在另一个项目中，但是具有相同的包名称）

package Connectivity;

import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class ClientX {

    ConnectInterface temp;

    public ClientX() {
        try {
            System.out.println("Searching for Server");
            String url = "jdbc:mysql://localhost/127.0.0.1:3306/xam_test1";
            Registry registry = LocateRegistry.getRegistry(1318);
            System.out.println("Registry located");
            this.temp = (ConnectInterface) registry.lookup(url);
            System.out.println("Server found");
            this.temp.getDBConnection();
            //this.welcomeBanner();
        } catch (Exception e) {
            System.out.println("Client Exception: " + e.toString());
        }
    }

    public String welcomeBanner() throws RemoteException {
        return temp.welcomeBanner();
    }

    public static void main(String[] args) throws RemoteException {

        ClientX clientX = new ClientX();
        System.out.println(clientX.welcomeBanner());

    }
}

服务器正在运行。我也对查询做了一些实验，它们给了我输出。但是当我运行客户端程序时，输出是这样的

Searching for Server
Registry located
Client Exception: java.rmi.NotBoundException: jdbc:mysql://localhost/127.0.0.1:3306/xam_test1

我想在整个会话期间保持客户端与服务器之间的不间断连接。请说明如何解决此问题。谢谢

如何将mysql数据库连接到RMI服务器？

0 个答案: