serializationdemo.java

Java网络编程与分布式计算, 主要分析java网络各方面的编程, 提供许多实用安全

import java.io.*;
import java.util.*;

// Chapter 4, Listing 5
public class SerializationDemo 
{
	public static void main(String args[])
	{
		try
		{
			Vector list;

			// Create a buffered reader for easy input
			BufferedReader reader = new BufferedReader
				( new InputStreamReader ( System.in ) );

			System.out.println ("Checking for previous serialized list");

			// Check to see if serialized list exists
			try
			{
				FileInputStream fin = new FileInputStream
					("list.out");

				// Connect an object input stream to the list
				ObjectInputStream oin = new ObjectInputStream
					( fin );

				try
				{
					// Read the vector back from the list
					Object obj = oin.readObject();

					// Cast back to a vector
					list = (Vector) obj;
				}
				catch (ClassCastException cce)
				{
					// Can't read it, create a blank one
					list = new Vector();
				}
				catch (ClassNotFoundException cnfe)
				{
					// Can't read it, create a blank one
					list = new Vector();
				}

				fin.close();
			}
			catch (FileNotFoundException fnfe)
			{
				// Create a blank vector
				list = new Vector();	
			}

			// Repeat indefinitely
			for (;;)
			{
				// Now, display menu
				System.out.println ("Menu :-");
				System.out.println ("1.. Add item");
				System.out.println ("2.. Delete item");
				System.out.println ("3.. List items");
				System.out.println ("4.. Save and quit");
				System.out.print   ("Choice : ");

				// Read choice
				String response = reader.readLine();

				// Convert to an int
				int choice = Integer.parseInt (response);

				switch (choice)
				{
				case 1 :
					// Add the item to list
					System.out.print ("Enter item : ");
					String item = reader.readLine();
					list.addElement(item);
					break;
				case 2 :
					// Delete the item from list
					System.out.print ("Enter item : ");
					String deadItem = reader.readLine();
					list.removeElement(deadItem);
					break;
				case 3 :
					// List the elements of the list
					for (Enumeration e = list.elements();
						 e.hasMoreElements();)
					{
						 System.out.println (e.nextElement());
					}
					break;
				case 4 :
					// Save list and terminate
					System.out.println ("Saving list");
					FileOutputStream fout = new FileOutputStream
						( "list.out" );

					// Construct an object output stream
					ObjectOutputStream oout = new ObjectOutputStream
						( fout );

					// Write the object to the stream
					oout.writeObject (list);
					fout.close();
					System.exit(0);
				}
			}
		}
		catch (IOException ioe)
		{
			System.err.println ("I/O error");
		}
	}
}