moviemodel.java

绝对经典!好动西和大家一起分享 呵呵 你们不应该如此限制的,不好

/* MovieModel - implements the movie model. Handles changes.
 * Copyright 2001, Bruce E. Wampler
 */
 
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MovieModel
    extends	WmvcModel
{
    private int currentMovieIndex;
    private Vector theList;
    private final int FILE_ID = 48879;	// 0xBEEF

    // need two changed flags - one if a new entry has been
    // added that is true only until the views update, and a
    // global one that remains true if anything has changed
    // until the list is saved
    private boolean listChanged;   // true until views updated
    private boolean editsMade;		// true until saved
    private File myFile;

    public ListIterator getMovieListIterator()
       { return theList.listIterator();}
    public boolean getListChanged() { return listChanged; }
    public boolean getEditsMade() { return editsMade; }
    public int getCurrentMovieIndex()
       { return currentMovieIndex; }
    public int getNumberOfMovies() { return theList.size(); }
    public File getFile() { return myFile; }
    
    public MovieModel()
    {
	editsMade = false;
	listChanged = false;
	theList = new Vector();
	myFile = null;
    }

    public void setCurrentMovieIndex(int movieNumber)
    {
	if (theList == null || theList.size() == 0) // valid?
	    return;
	// Validate number passed in, wrap appropriately
	if (movieNumber < 0)
	    movieNumber = theList.size() - 1;
	if (movieNumber >= theList.size())
	    movieNumber = 0;

	currentMovieIndex = movieNumber;  // change the movie
	notifyViews();			  // update
    }
    
    public void addMovie(Movie movie)
    {
	if (movie == null)		// some validation
	    return;
	editsMade = true;  	   // we've made some changes
	listChanged = true;

	ListIterator it = getMovieListIterator();
	int nextI = 0;

	while (it.hasNext())
	{
	    // Assume list is sorted, so as soon as we find the
	    // first entry that is > than this one, we insert
	    // it before that one.

	    nextI = it.nextIndex();	// index of next entry
	    Movie m = (Movie) it.next();
	    String adding = movie.getTitle();
	    String curName = m.getTitle();
	    if (adding.compareToIgnoreCase(curName) <= 0)
	        break;			// curName > adding
	}

	if (!it.hasNext())	// add at end (also if 1st time)
	{
	    theList.add(movie);
	    // make it current movie
	    setCurrentMovieIndex(theList.size() - 1);
	}
	else			// add it before nextI
	{
	    theList.add(nextI,movie);
	    setCurrentMovieIndex(nextI);
	}
    }
    
    public void deleteCurrentMovie()
    {
	if (theList.size() <= 0)
	    return;

	editsMade = true;	// we've made some changes
	listChanged = true;

	theList.removeElementAt(currentMovieIndex);
	setCurrentMovieIndex(currentMovieIndex);
    }
    
    public void replaceCurrentMovie(Movie movie)
    {
	if (movie == null)
	    return;

	theList.setElementAt(movie,currentMovieIndex);
	editsMade = true;	// we've made some changes
	listChanged = true;
	notifyViews();
    }
    
    public boolean saveMovies()
    {
	return saveMoviesAs(myFile);
    }
    
    public boolean saveMoviesAs(File file)
    {
	if (file != null)
	{
	    try
	    {
	    	DataOutputStream out = new DataOutputStream(
	    	        new BufferedOutputStream(
	    	          new FileOutputStream(file)));
	    	out.writeInt(FILE_ID);
		ListIterator it = getMovieListIterator();
		while (it.hasNext())
		{
		    Movie m = (Movie) it.next();
		    m.writeMovie(out);
		}
		out.flush(); out.close();
		myFile = file;		// remember name
	    }
	    catch (IOException e)
	    {
		JOptionPane.showMessageDialog(
		    WmvcApp.getFrame(),
		    "Error opening file: " + e,
			 "MovieCat Error",
		    JOptionPane.ERROR_MESSAGE);
		return false;
	    }
	}
	else
	    return false;
	
	editsMade = false;		// no edits now!
	return true;
    }

    public boolean openMovies(File file)
    {
	if (file != null)
	{
	    myFile = file;		// remember the name
	    try
	    {
	    	DataInputStream in = new DataInputStream(
	    	        new BufferedInputStream(
	    	          new FileInputStream(file)));
		// check if file was made by us
		if (in.readInt() != FILE_ID)
		{
		    in.close();
		    myFile = null;
		    JOptionPane.showMessageDialog(
		        WmvcApp.getFrame(),
			file.getName() +
			 " is not a valid MovieCat file.",
			 "MovieCat Error",
			JOptionPane.ERROR_MESSAGE);
		    return false;
		}
		for ( ; ; )	// do until catch EOF Exception
		{
		    Movie m = new Movie();
		    if (!m.readMovie(in))
		    	break;
		    theList.add(m);
		}
	    }
	    catch (IOException e)
	    {
		JOptionPane.showMessageDialog(
		    WmvcApp.getFrame(),
		    "Error reading file: " + e,
			 "MovieCat Error",
		    JOptionPane.ERROR_MESSAGE);
		myFile = null;
		return false;
	    }

	    editsMade = false;		// no edits to start
	    listChanged = true;
	    notifyViews();
	    return true;
	}
	else
	    return false;
    }
    
    public boolean closeMovies()
    {
	// Just close - Views responsible to save before closing
	myFile = null;			// reset to empty values
	theList.clear();
	editsMade = false;		// no edits now!
	listChanged = true;
	notifyViews();
	return true;
    }
    
    public Movie getCurrentMovie()
    {
	if (currentMovieIndex < 0 
	             && currentMovieIndex >= theList.size())
	    return null;
	else if (theList.size() == 0)
	    return null;
	else
	    return (Movie)theList.elementAt(currentMovieIndex);
    }
    
    public void notifyViews()
    {
	super.notifyViews();
	// updating views makes list correct
	listChanged = false;
    }
}