远程方法调用的实现

使用RMI(远程方法调用)可以简化客户端与服务端之间的交互过程，当客户端在与服务端交互时，就感觉像是客户端在调用本地的方法
实现步骤：

• 要实现RMI，必须要定义一个接口，该接口继承自import java.rmi.Remote类；在该类中声明服务端提供的方法，每一个方法必须是静态的并且每个方法后应该要
  有throws RemoteException的声明，如下：

public interface SevFun extends Remote {	
   public boolean checkpassword(int idnum,String key) throws RemoteException;
   public int genxing(int idnum,int sco) throws RemoteException;
   public int zhuce(int idnum, String pas) throws RemoteException;
   public int chaxun(int idnum) throws RemoteException;
   public int shanchu(int idnum) throws RemoteException;
   public int[] startGame() throws RemoteException;
   public double checkresult(String str) throws RemoteException;
   public int[][] chaxunqianshi() throws RemoteException ;
   public int [] checkIDqianshi() throws RemoteException ;
   public int [] checkScoreqianshi() throws RemoteException;
}

• 定义一个类继承在上一步我们所写的接口，在该类中重写接口中的方法实现我们需要的功能，如下：

public class database  extends UnicastRemoteObject implements SevFun{
	protected database() throws RemoteException {
		super();
	}
	//验证密码：
	public boolean checkpassword(int idnum,String  pas)
	{
		String password = " ";
		String sql = "select Password from Vincenttest.kcsj where ID = '"+idnum+"'";
		try {
			Statement sta = test01.getconnection().createStatement();
			ResultSet rs = sta.executeQuery(sql);
			while(rs.next()){
				password = rs.getString("Password");  //在次数根据ID获取相应的密码；
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
												//在此数将输入的密码与数据库中得密码进行比较
		if(pas.equals(password))			
		{
			return true ;
		}
		else
		{
			return false ;
		}

	}

• 服务端绑定，绑定远程调用的对象，声明端口号如下：

public class Sever {
		SevFun severefun;
		public void ser() throws RemoteException, MalformedURLException, AlreadyBoundException {
			severefun = new database();
			LocateRegistry.createRegistry(8888);
			Naming.bind("rmi://192.168.1.101:8888/severfun",severefun);
			System.out.println("服务端:对象绑定成功！");
		}
		public static void main(String[] args) {
			try {
				Sever sever = new Sever();
				sever.ser();
				while(true);
			} catch (RemoteException | MalformedURLException | AlreadyBoundException e) {
				e.printStackTrace();
			}
		}
}

• 客户端的远程调用：例如登录的校验

public class client {
	public SevFun sevfun;
	public void clien() throws MalformedURLException, RemoteException, NotBoundException {
		sevfun =  (SevFun) Naming.lookup("rmi://192.168.1.101:8888/severfun");
		Scanner input = new Scanner(System.in);
		int ID = 0;
		System.out.println("请输入登录名：");
		ID = input.nextInt();
		System.out.println("请输入密码：");
		String  key = input.next();
		if (sevfun.checkpassword(ID, key) ) {
			System.out.println("登录成功！");
			break;
		}
		else {
			System.out.println("用户名或密码错误请重新输入！！！");
			}
		
		}
		public static void main(String[] args) {
		client cilen = new client();
		try {
			cilen.clien();
		} catch (MalformedURLException | RemoteException | NotBoundException e) {
			e.printStackTrace();
		}
	}
}