LogN_StudentMgmtClass_Main.java

package p3_package;

/**
 * Driver class for testing LogN_SortDriverClass tools
 * 
 * @author MichaelL
 *
 */
public class LogN_StudentMgmtClass_Main
   {
    /**
     * constant definition of space
     */
    private static final char SEMI_COLON = ';';

    /**
     * Main method driver for testing sorting operations
     * 
     * @param args String array arguments not used
     */
    public static void main(String[] args)
       {
        int numItems = 50;
        StudentClass[] msStrArray, qsStrArray; 
       
        // Upload, sort, display using merge sort
        msStrArray = uploadData( "inData.txt", numItems );

        System.out.println( "List before Merge Sort:");
        displayStudents( msStrArray, numItems );

        LogN_StudentMgmtClass.runMergeSort( msStrArray, numItems );

        System.out.println( "\nList after Merge Sort:");
        displayStudents( msStrArray, numItems );
        
        // Upload, sort, display using merge sort
        qsStrArray = uploadData( "inData.txt", numItems );

        System.out.println( "\nList before Quick Sort:");
        displayStudents( qsStrArray, numItems );

        LogN_StudentMgmtClass.runQuickSort( qsStrArray, numItems );
        
        System.out.println( "\nList after Quick Sort:");
        displayStudents( qsStrArray, numItems );
        
       }

    /**
     * Displays strings from array
     * 
     * @param nameList String array to be displayed
     * 
     * @param numNames integer number of names to be displayed
     */
    public static void displayStudents( StudentClass[] nameList, int numNames )
       {
        int index;
        
        for( index = 0; index < numNames; index++ )
           {
            System.out.format( "%2d: ", index + 1 );
            System.out.println( nameList[ index ].toString() );
           }
        
        System.out.println();
       }
    
    /**
     * Uploads String data from a formatted text data file
     * <p>
     * Note: uses compareStrings method from LogN_SortDriverClass
     * 
     * @param fileName String file name of file
     * 
     * @param arrCapacity integer capacity specification 
     * for returned String array; limits number of strings to be uploaded
     * 
     * @return String data array with data loaded
     */
    public static StudentClass[] uploadData( String fileName, int arrCapacity )
       {
        File_Input_Class fileInRef = new File_Input_Class();
        StudentClass[] studentArray = null;
        String nameString;
        int idVal;
        char genderChar;
        // dummyChar data only used to capture semicolon in file stream
        @SuppressWarnings( "unused") char dummyChar;
        double gpaVal;
        
        int index = 0;
       

        // Open file
        if( fileInRef.openInputFile( fileName ) )
           {    
            studentArray = new StudentClass[ arrCapacity ];
            
            // get name, ignores semicolon
            nameString = fileInRef.getString( SEMI_COLON );
            
            while( index < arrCapacity && !fileInRef.checkForEndOfFile() )
               {
                // gets integer, ignores semicolon
                idVal = fileInRef.getInt();
                
                // gets char, extra call to ignore semicolon
                genderChar = fileInRef.getChar();
                dummyChar = fileInRef.getChar();
                
                // get GPA, ignores semicolon
                gpaVal = fileInRef.getDouble();
                
                studentArray[ index ] = new StudentClass( nameString, 
                                                    idVal, genderChar, gpaVal );
                               
                // get name, ignores semicolon
                nameString = fileInRef.getString( SEMI_COLON );
                
                index++;
               }
                        
            fileInRef.closeInputFile();
           }
       
        return studentArray;       
       }
       
   }