moviegraph/GraphDriver.java

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

/**
 * 
 * @author Coleman
 * This class provides a wrapper for the Graph object and parses all input files.
 */
public class GraphDriver	{
	
	// only need one graph
	private static Graph mygraph;
	
	/**
	 * Prints a path of actors from an ArrayList.
	 * @param path An ArrayList returned from shortestPath or the like.
	 */
	private static void printPath ( ArrayList path )	{
		for ( int x = 0; x < path.size() - 1; x++ )	{
			Comparable one = ((GraphNode)path.get ( x )).getKey();
			Comparable two = ((GraphNode)path.get ( x + 1 )).getKey();
			String movie = mygraph.getMovie ( one, two );
			if ( !movie.equals ( "(0)" ) )
				System.out.println ( "'" + one.toString() + "' starred with '" + two.toString() + "' in the movie '" + movie + "'" );
		}
	}
	
	/**
	 * Parses and inserts all data from an input file.
	 * @param filename Name of the file to be read.
	 * @param filenum Number of the file in the sequence, can be -1 if not known.
	 * @param len Total number of input files.
	 */
	private static void readFile ( String filename, int filenum, int len )	{
		BufferedReader read = null;
		ArrayList actors = new ArrayList();
		try	{
			String t = "";
			if ( filenum != -1 )	{
				t = " (" + (filenum + 1) + "/" + len + ")";
			}
			System.out.println ( "***Reading from file: " + filename + t );
			read = new BufferedReader ( new FileReader ( filename ) );
			//this big loop reads in the movie name and all the actors
			while ( read.ready() )	{
				String line = read.readLine();
				if ( line.equals ( "" ) )	continue;
				//split the date off the movie name, makes for easier tie breaking.
				String data[] = line.split ( "\\(\\d{4}\\)\\s*$" );
				String date =  line.substring ( data[0].length() + 1, data[0].length() + 5 );
				data[0].trim();
				
				//get all the actors in a usable form
				line = read.readLine();
				// NEW
				// added check for read.ready() : no longer must have two lines ending input file
				while ( read.ready() && !line.equals ( "" ) )	{
					actors.add ( line );
					line = read.readLine();
				}
				String actor[] = new String[actors.size()];
				actor = (String [])actors.toArray ( actor );
				//now we must add all the actors into the graph
				for ( int x = 0; x < actor.length; x++ )	{
					try	{
						mygraph.addVertex ( new GraphNode ( actor[x] ) );
					}
					catch ( GraphException exception )	{}
				}
				//and add an edge between all the actors for this movie
				for ( int x = 0; x < actor.length - 1; x++ )	{
					for ( int y = x + 1; y < actor.length; y++ )	{
						try	{
							mygraph.addEdge ( actor[x], actor[y], data[0], date );
						}
						catch ( GraphException exception )	{}
					}
				}
				//start all over again
				actors.clear();
			}// end while
		}
		catch ( IOException exception )	{
			System.out.println ( "Error reading the file: " + filename );
			exception.printStackTrace();
		}
	}
	
	public static void main ( String[] args )	{  
		if ( args.length < 1 )	{
			System.out.println ( "Usage: java GraphDriver [input files]" );
			System.exit ( 1 );
		}
		
		mygraph = new Graph();
		
		for ( int filenum = 0; filenum < args.length; filenum++ )	{
			readFile ( args[filenum], filenum, args.length );
		}
		
		/* this block is the user interface. it is simple, but yet still allows for all
		 * the neccessary functionality of the project.
		 */
		String command = "";
		while ( !command.equals ( "quit" ) )	{
			System.out.println ( "*Commands*\t*Description*" );
			System.out.println ( "path\t\tDjikstra's Shortest Path" );
			System.out.println ( "bfs\t\tBreadth-First Search" );
			System.out.println ( "add\t\tUpdate Graph From File" );
			System.out.println ( "dia\t\tCompute Diameter Of Graph" );
			System.out.println ( "quit\t\tQuit" );
			System.out.print ( "> " );
			BufferedReader in = new BufferedReader ( new InputStreamReader ( System.in ) );
			try	{
				command = in.readLine().trim();
			}
			catch ( IOException exception )	{
				System.out.println ( "bailing from command:" );
				exception.printStackTrace();
			}
			if ( command.equals( "path" ) )	{
				System.out.print ( "actors (one,two)> " );
				String actors[] = null;
				try	{
					actors = (String [])in.readLine().trim().split ( "," );
				}
				catch ( IOException exception )	{
					System.out.println ( "bailing from path:" );
					exception.printStackTrace();
				}
				if ( actors.length != 2 )	{
					System.out.println ( "Enter two actors only!" );
				}
				else	{
					ArrayList path = mygraph.shortestPath ( actors[0].trim(), actors[1].trim() );
					printPath ( path );
				}
			}
			else if ( command.equals( "bfs" ) )	{
				System.out.print ( "actors (one,two)> " );
				String actors[] = null;
				try	{
					actors = (String [])in.readLine().trim().split ( "," );
				}
				catch ( IOException exception )	{
					System.out.println ( "bailing from bfs:" );
					exception.printStackTrace();
				}
				if ( actors.length != 2 )	{
					System.out.println ( "Enter two actors only!" );
				}
				else	{
					ArrayList path = mygraph.bfs ( actors[0].trim(), actors[1].trim() );
					printPath ( path );
				}
			}
			else if ( command.equals ( "add" ) )	{
				System.out.print ( "read from file> " );
				String filename[] = null;
				try	{
					filename = (String [])in.readLine().trim().split ( " " );
				}
				catch ( IOException exception )	{
					System.out.println ( "bailing from add:" );
					exception.printStackTrace();
				}
				for ( int q = 0; q < filename.length; q++ )	{
					readFile ( filename[q], q, filename.length );
				}
			}
			else if ( command.equals ( "dia" ) )	{
				System.out.println ( "Please wait while searching through " + mygraph.numVertices() + " vertecies..." );
				System.out.println ( "The diameter of the graph is " + mygraph.diameter() );
			}
			else if ( command.equals ( "quit" ) )	{
				break;
			}
			else	{
				System.out.println ( "Unknown Command: '" + command + "'" );
			}
			System.out.println();
		}
	}
}