resourcemanagerimpl.java

分布式数据库原形代码 可以支持个用户同时登陆到数据库中查询需要的资源

package transaction;

import lockmgr.*;
import java.rmi.*;

/** 
 * Resource Manager for the Distributed Travel Reservation System.
 * 
 * Description: toy implementation of the RM, for initial testing
 */

public class ResourceManagerImpl 
    extends java.rmi.server.UnicastRemoteObject
    implements ResourceManager {
    
    // in this toy, we don't care about location or flight number
    protected int flightcounter, flightprice, carscounter, carsprice, roomscounter, roomsprice;
    
    protected int xidCounter;
    
    public static void main(String args[]) {
	System.setSecurityManager(new RMISecurityManager());

	String rmiName = System.getProperty("rmiName");
	if (rmiName == null || rmiName.equals("")) {
	    rmiName = ResourceManager.DefaultRMIName;
	}

	String rmiRegPort = System.getProperty("rmiRegPort");
	if (rmiRegPort != null && !rmiRegPort.equals("")) {
	    rmiName = "//:" + rmiRegPort + "/" + rmiName;
	}

	try {
	    ResourceManagerImpl obj = new ResourceManagerImpl();
	    Naming.rebind(rmiName, obj);
	    System.out.println("RM bound");
	} 
	catch (Exception e) {
	    System.err.println("RM not bound:" + e);
	    System.exit(1);
	}
    }
    
    
    public ResourceManagerImpl() throws RemoteException {
	flightcounter = 0;
	flightprice = 0;
	carscounter = 0;
	carsprice = 0;
	roomscounter = 0;
	roomsprice = 0;
	flightprice = 0;

	xidCounter = 1;
    }


    // TRANSACTION INTERFACE
    public int start()
	throws RemoteException {
	return (xidCounter++);
    }

    public boolean commit(int xid)
	throws RemoteException, 
	       TransactionAbortedException, 
	       InvalidTransactionException {
	System.out.println("Committing");
	return true;
    }

    public void abort(int xid)
	throws RemoteException, 
               InvalidTransactionException {
	return;
    }


    // ADMINISTRATIVE INTERFACE
    public boolean addFlight(int xid, String flightNum, int numSeats, int price) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	flightcounter += numSeats;
	flightprice = price;
	return true;
    }

    public boolean deleteFlight(int xid, String flightNum)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	flightcounter = 0;
	flightprice = 0;
	return true;
    }
		
    public boolean addRooms(int xid, String location, int numRooms, int price) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	roomscounter += numRooms;
	roomsprice = price;
	return true;
    }

    public boolean deleteRooms(int xid, String location, int numRooms) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	roomscounter = 0;
	roomsprice = 0;
	return true;
    }

    public boolean addCars(int xid, String location, int numCars, int price) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	carscounter += numCars;
	carsprice = price;
	return true;
    }

    public boolean deleteCars(int xid, String location, int numCars) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	carscounter = 0;
	carsprice = 0;
	return true;
    }

    public boolean newCustomer(int xid, String custName) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return true;
    }

    public boolean deleteCustomer(int xid, String custName) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return true;
    }


    // QUERY INTERFACE
    public int queryFlight(int xid, String flightNum)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return flightcounter;
    }

    public int queryFlightPrice(int xid, String flightNum)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return flightprice;
    }

    public int queryRooms(int xid, String location)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return roomscounter;
    }

    public int queryRoomsPrice(int xid, String location)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return roomsprice;
    }

    public int queryCars(int xid, String location)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return carscounter;
    }

    public int queryCarsPrice(int xid, String location)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return carsprice;
    }

    public int queryCustomerBill(int xid, String custName)
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	return 0;
    }


    // RESERVATION INTERFACE
    public boolean reserveFlight(int xid, String custName, String flightNum) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	flightcounter--;
	return true;
    }
 
    public boolean reserveCar(int xid, String custName, String location) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	carscounter--;
	return true;
    }

    public boolean reserveRoom(int xid, String custName, String location) 
	throws RemoteException, 
	       TransactionAbortedException,
	       InvalidTransactionException {
	roomscounter--;
	return true;
    }


    // TECHNICAL/TESTING INTERFACE
    public boolean shutdown()
	throws RemoteException {
	System.exit(0);
	return true;
    }

    public boolean dieNow() 
	throws RemoteException {
	System.exit(1);
	return true; // We won't ever get here since we exited above;
	             // but we still need it to please the compiler.
    }

    public boolean dieBeforePointerSwitch() 
	throws RemoteException {
	return true;
    }

    public boolean dieAfterPointerSwitch() 
	throws RemoteException {
	return true;
    }

}