stockclient.java

关系型数据库 Postgresql 6.5.2

package example.corba;

import java.io.*;
import java.sql.*;
import org.omg.CosNaming.*;

/**
 * This class is the frontend to our mini CORBA application.
 *
 * It has no GUI, just a text frontend to keep it simple.
 *
 * $Id: StockClient.java,v 1.1 1999/01/25 21:22:03 scrappy Exp $
 */
public class StockClient
{
    org.omg.CosNaming.NamingContext nameService;
    
    stock.StockDispenser dispenser;
    stock.StockItem	 item;
    
    BufferedReader	 in;
    
    public StockClient(String[] args) {
	try {
	    // We need this for our IO
	    in = new BufferedReader(new InputStreamReader(System.in));
	    
	    // Initialize the orb
	    org.omg.CORBA.ORB orb = org.omg.CORBA.ORB.init(args,null);
	    
	    // Get a reference to the Naming Service
	    org.omg.CORBA.Object nameServiceObj = orb.resolve_initial_references("NameService");
	    if(nameServiceObj==null) {
		System.err.println("nameServiceObj == null");
		return;
	    }
	    
	    nameService = org.omg.CosNaming.NamingContextHelper.narrow(nameServiceObj);
	    if(nameService==null) {
		System.err.println("nameService == null");
		return;
	    }
	    
	    // Resolve the dispenser
	    NameComponent[] dispName = {
		new NameComponent("StockDispenser","Stock")
	    };
	    dispenser = stock.StockDispenserHelper.narrow(nameService.resolve(dispName));
	    if(dispenser==null) {
		System.err.println("dispenser == null");
		return;
	    }
	    
	    // Now run the front end.
	    run();
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	    System.exit(1);
	}
    }
    
    public static void main(String[] args) {
	new StockClient(args);
    }
    
    public void run() {
	// First reserve a StockItem
	try {
	    item = dispenser.reserveItem();
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	    System.exit(1);
	}
	
	mainMenu();
	
	// finally free the StockItem
	try {
	    dispenser.releaseItem(item);
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	    System.exit(1);
	}
    }
    
    private void mainMenu() {
	boolean run=true;
	while(run) {
	    System.out.println("\nCORBA Stock System\n");
	    System.out.println("  1 Display stock item");
	    System.out.println("  2 Remove item from stock");
	    System.out.println("  3 Put item into stock");
	    System.out.println("  4 Order item");
	    System.out.println("  5 Display all items");
	    System.out.println("  0 Exit");
	    int i = getMenu("Main",5);
	    switch(i)
		{
		case 0:
		    run=false;
		    break;
		    
		case 1:
		    displayItem();
		    break;
		    
		case 2:
		    bookOut();
		    break;
		    
		case 3:
		    bookIn();
		    break;
		    
		case 4:
		    order(0);
		    break;
		    
		case 5:
		    displayAll();
		    break;
		}
	}
    }
    
    private void displayItem() {
	try {
	    int id = getMenu("\nStockID to display",item.getLastID());
	    if(id>0) {
		item.fetchItem(id);
		System.out.println("========================================");
		
		String status = "";
		if(!item.isItemValid())
		    status=" ** Superceded **";
		
		int av = item.getAvailable();
		
		System.out.println("      Stock ID: "+id+status+
				   "\nItems Available: "+av+
				   "\nItems on order: "+item.getOrdered()+
				   "\n   Description: "+item.getDescription());
		System.out.println("========================================");
		
		if(av>0)
		    if(yn("Take this item out of stock?")) {
			int rem=1;
			if(av>1)
			    rem=getMenu("How many?",av);
			if(rem>0)
			    item.removeStock(rem);
		    }
		
	    }
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	}
    }
    
    private void bookOut() {
	try {
	    int id = getMenu("\nStockID to take out",item.getLastID());
	    if(id>0) {
		item.fetchItem(id);
		int av = item.getAvailable();
		if(av>0)
		    if(yn("Take this item out of stock?")) {
			int rem=1;
			if(av>1)
			    rem=getMenu("How many?",av);
			if(rem>0)
			    item.removeStock(rem);
		    }
		    else {
			System.out.println("This item is not in stock.");
			int order = item.getOrdered();
			if(order>0)
			    System.out.println("There are "+item.getOrdered()+" items on order.");
			else {
			    if(item.isItemValid()) {
				System.out.println("You will need to order some more "+item.getDescription());
				order(id);
			    } else
				System.out.println("This item is now obsolete");
			}
		    }
	    } else
		System.out.println(item.getDescription()+"\nThis item is out of stock");
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	}
    }
    
    // book an item into stock
    private void bookIn() {
	try {
	    int id = getMenu("\nStockID to book in",item.getLastID());
	    item.fetchItem(id);
	    System.out.println(item.getDescription());
	    
	    if(item.getOrdered()>0) {
		int am = getMenu("How many do you want to book in",item.getOrdered());
		if(am>0)
		    item.addNewStock(am);
	    } else
		System.out.println("You don't have any of this item on ordered");
	    
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	}
    }
    
    // Order an item
    private void order(int id) {
	try {
	    if(id==0)
		id = getMenu("\nStockID to order",item.getLastID());
	    item.fetchItem(id);
	    System.out.println(item.getDescription());
	    int am = getMenu("How many do you want to order",999);
	    if(am>0)
		item.orderStock(am);
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	}
    }
    
    private void displayAll() {
	try {
	    boolean cont=true;
	    int nr=item.getLastID();
	    String header = "\nId\tAvail\tOrdered\tDescription";
	    System.out.println(header);
	    for(int i=1;i<=nr && cont;i++) {
		item.fetchItem(i);
		System.out.println(""+i+"\t"+item.getAvailable()+"\t"+item.getOrdered()+"\t"+item.getDescription());
		if((i%20)==0) {
		    if((cont=yn("Continue?")))
			System.out.println(header);
		}
	    }
	} catch(Exception e) {
	    System.out.println(e.toString());
	    e.printStackTrace();
	}
    }
    
    private int getMenu(String title,int max) {
	int v=-1;
	while(v<0 || v>max) {
	    System.out.print(title);
	    System.out.print(" [0-"+max+"]: ");
	    System.out.flush();
	    try {
		v = Integer.parseInt(in.readLine());
	    } catch(Exception nfe) {
		v=-1;
	    }
	}
	return v;
    }
    
    private boolean yn(String title) {
	try {
	    while(true) {
		System.out.print(title);
		System.out.flush();
		String s = in.readLine();
		if(s.startsWith("y") || s.startsWith("Y"))
		    return true;
		if(s.startsWith("n") || s.startsWith("N"))
		    return false;
	    }
	} catch(Exception nfe) {
	    System.out.println(nfe.toString());
	    nfe.printStackTrace();
	    System.exit(1);
	}
	return false;
    }
}