Assorted errors prevention execution

// DVDInventoryProgram.java
// Inventory program that uses an array to store DVD name, DVD number, amount in
// stock, DVD price, DVD value, value of complete inventory, and uses a GUI.


public class DVDInventoryValue {
    private string ProductName;
    private int stock[];

    // constuctor initializes inventoryName and stock array
    public float InventoryValue( String name, int stockArray[] ) {
        
        InventoryName = name; // initialize inventory name
        stock = stockArray; // store stock
    } // end InventoryValue constructor
    
    // method to set the inventory name
    public void setInventoryName( string name) {
        inventoryName = name; // store the inventory name
    } // end method setInventoryName
    
    // method to retrieve the inventory name
    public string getInventoryName() {
        return InventoryName;
    } // end method get InventoryName
    
    // display a message to the DVD Inventory Value user
    public void displayMessage() {
        // get InventoryName gets the name of the inventory
        System.out.printf( "This is the inventory for\n%s!\n\n",
                getInventoryName() );
    } // end method display message to DVD Inventory Value user
    
    public class DVDArtist {
        private String DVDName;
        private integer DVDNumber;
        private double DVDStockAmount; // amount in stock
        private double DVDPrice; // price of CD
        private double DVDRestockingFeeRate; // restocking percentage
        private double DVDInventoryValue; // value of inventory
    
        // seven-argument constructor
        public DVDArtist(String name,
                int number, double stock, double price, double rate, double value ) {
            DVDName = name; // validate and store DVD name
            DVDNumber = number; // validate and store DVD number
            setDVDPrice( price ); // validate and store DVD price
            setDVDRestockingFeeRate( rate ); // validate and store DVD restocking fee rate
            setDVDInventoryValue( value ); // validate and store DVD inventory value
        } // end DVDArtist constructor
        
        // set DVD name
        public void setDVDName( String name ) {
            DVDName = name;
        } // end method set DVD Name
        
        // return DVD name
        public String getDVDName();{
            return DVDName;
        } // end method return DVD Name
        
        // set DVD number
        public void setDVDNumber( String number ) {
            DVDNumber = number; // should validate
        } // end method set DVD Number
        
        // return DVD number
        public String getDVDNumber() {
            return DVDNumber;
        } // end method return DVD Number
        
        // set amount of DVDs in stock
        public void setDVDStockAmount( double stock ) {
            stockAmount = ( stock < 0.0 ) ? 0.0 : stock;
        } // end method setDVDStockAmount
        
        // return amount in of DVDs in stock
        public double getDVDStockAmount() {
            return DVDStockAmount;
        } // end method getDVDStockAmount
        
        // set DVD price
        public void setDVDPrice( double rate ) {
            DVDPrice = ( price < 0.0 ) ? 0.0 : price;
        } // end method setDVDPrice
        
        // return DVD price
        public double getDVDPrice() {
            return DVDPrice;
        } // end method getDVDPrice
        
        // set DVD restocking fee rate
        public void setDVDRestockingFeeRate( double rate ) {
            DVDRestockingFeeRate = ( rate o.5 ) rate : 0.5; // error is: ")" expected
        } // end method set DVD restocking fee rate
        
        // return DVD restocking fee rate
        public double getDVDRestockingFeeRate() {
            return DVDRestockingFeeRate;
        } // end method get DVD restocking fee rate
        
        // set DVD inventory value
        public void setDVDInventoryValue( double value ) {
            DVDInventoryValue = ( value < 0.0 ) ? 0.0 : value;
        } // end method set DVD inventory value
        
        // return DVD inventory value
        public double getDVDInventoryValue() {
            return DVDInventoryValue;
        } // end method get DVD inventory value
        
        // calculate feeinventory
        public double feeinventory() {
            return DVDInventoryValue + ( restockingFeeRate * stock );
        } // end method feeinventory
        
        // return String representation of ArtistName
        public String toString() {
            return String.format(
                    "%s: %s %s\n%s: %s\n%s: %.2f\n%s: %.2f\n%s: %.2f",
                    "DVD Name", DVDname, "DVD Number", DVDNumber,
                    "DVDs in Stock", DVDStockAmount, "DVD Price", DVDPrice,
                    "DVD Restocking Fee Rate", DVDRestockingFeeRate,
                    "Value of DVD Inventory", DVDInventoryValue );
        } // end method toString
        
        // perform various operations on the data
        public void processStock() {
            // output Stock array
            outputStock();
            
            // call method getValue to calculate the value of product
            System.out.printf( "Product value is %.2f\n",getValue() );
            
            // call method getInventory to calculate entire value of inventory
            System.out.printf( "Inventory value is %d\n",getInventory() );
            
        } // end method processStock
        
        {
            int total = 0; // initialize total
            // sum stock for one product
            for ( int stock : stock )
                total += stock;
        }
        
        // output the contents of the stock array
        public void outputStock() {
            System.out.println( "The stock is :\n" );
            
            // output each product name's stock
            for ( int product = 0; product < stock.length; product++ )
                System.out.printf( "Product %2d: %3d\n",
                        product + 1, stock[ product ] );
        } // end method outputStock
        
        // use of JOption Pane for input and output
        
         import javax.swing.JOptionPane; // illegal start of type and <identifier> expected
        
        public class Display {
           
            public static void main( String args[] ) {
                // obtain user input from JOptionPane input dialogs
                String DVDNumber =
                        JOptionPane.showInputDialog( "Enter DVD Number" );
                
                if ( DVDNumber < 0 ) {
                    System.out.println(" DVD Number invalid,  please enter a positive number" );
                } else  {
                    
                    String DVDName =
                            JOptionPane.showInputDialog( "Enter DVD Name" );
                    String DVDStockAmount =
                            JOptionPane.showInputDialog( "Enter amount of DVDs in stock" );
                    
                    if ( DVDStockAmount < 0 ) {
                        System.out.println(" Amount of DVDs in Stock is Invalid, please enter a positive number" );
                    } else  {
                        
                        String DVDPrice =
                                JOptionPane.showInputDialog( "Enter DVD Price" );
                        
                        if ( DVDPrice < 0 ) {
                            System.out.println(" DVD Price is Invalid, please enter a positive number" );
                        } else  {
                            
                            // convert String inputs to int values for use in calculation
                            int number1 = Integer.parseInt( DVDStockAmount );
                            int number2 = Integer.parseInt( DVDPrice );
                            
                            DVDInventoryValue = number1 * number2; // multiply numbers
                            
                            // create DVDInventoryValue object
                            DVDInventoryValue DVDInventoryValue1 = new DVDInventoryValue(
                                    "DVD Number", "DVD Name", "Amount of DVDs in Stock", "DVD Price" );
                            
                            // display initial value of DVD number for DVDInventoryValue
                            System.out.printf( "DVDInventoryValue1 DVD Number is: %d\n",
                                    DVDInventoryValue1.getDVDNumber() );
                            System.out.printf( "DVDInventoryValue1 DVD Name is %s\n",
                                    DVDInventoryValue1.getDVDName() );
                            System.out.printf( "DVDInventoryValue1 Amount of DVDs in Stock is %d\n",
                                    DVDInventoryValue1.getDVDStockAmount() );
                            System.out.print( "DVDInventoryValue1 DVD Price is %d/n",
                                    DVDInventoryValue1.getDVDPrice() );
                            
                            DVDInventoryValue = amount * price; // multiply numbers
                            
                            while ( DVDNumber <= 0 ) {
                                System.out.printf( "DVDInventoryValue is %d\n", DVDInventoryValue ); // display
                                // DVD Inventory Value
                            } // end while
                        
                            //Creating radio buttons using ButtonGroup and JRadioButton.
                            
                            import java.awt.FlowLayout;    // all 8 imports have an error of illegal start of expression                        
                            import java.awt.DVDs;                           
                            import java.awt.event.ItemListener;                            
                            import java.awt.event.ItemEvent;                            
                            import javax.swing.JFrame;                          
                            import javax.swing.JTextField;                           
                            import javax.swing.JRadioButton;                            
                            import javax.swing.ButtonGroup;
                            
                            public class RadioButtonFrame extends JFrame { // error is: illegal start of expression and ';' expected
                                private JTextField textField; // used to display field changes
                                private field DVDNumber; // field for DVD number
                                private field DVDName; // field for DVD name
                                private field DVDStockAmount; // field for amount of DVDs in stock
                                private field DVDPrice; // field for DVD price
                                private field DVDInventoryValue; // field for DVD inventory value
                                private field previous; // field for previous selection
                                private field next; // field for next selection
                                private JRadioButton DVDNumberJRadioButton; // selects DVD number field
                                private JRadioButton DVDNameJRadioButton; // selects DVD name field
                                private JRadioButton DVDStockAmountJRadioButton; // selects amount of DVDs in stock field
                                private JRadioButton DVDPriceJRadioButton; // selects DVD price field
                                private JRadioButton DVDInventoryValueJRadioButton; // selects DVD inventory value field
                                private JRadioButton previousJRadioButton; // selects previous selection field
                                private JRadioButton nextJRadioButton; // selects next selection field
                                
                                // RadioButtonFrame constructor adds JRadioButtons to JFrame
                                public RadioButtonFrame() {
                                    super( "RadioButton Test");
                                    setLayout( new FlowLayout() ); // set frame layout
                                    
                                    textfield = new JTextField( "Watch the field change", 25 );
                                    add( textField ); // add textField to JFrame
                                    
                                    // create radio buttons
                                    DVDNumberJRadioButton = new JRadioButton( "DVDNumber", true );
                                    DVDNameJRadioButton = new JRadioButton( "DVDName", false );
                                    DVDStockAmountJRadioButton = new JRadioButton( "DVDStockAmount", false );
                                    DVDPriceJRadioButton = new JRadioButton( "DVDPrice", false );
                                    DVDInventoryValueJRadioButton = new JRadioButton( "DVDInventoryValue", false );
                                    previousJRadioButton = new JRadioButton( "previous", false );
                                    nextJRadioButton = new JRadioButton( "next", false );
                                    add( DVDNumberJRadioButton ); // add DVD number button to JFrame367
                                    add( DVDNameJRadioButton ); // add DVD name button to JFrame
                                    add( DVDStockAmountJRadioButton ); // add DVD stock amount button to JFrame
                                    add( DVDPriceJRadioButton ); // add DVD price button to JFrame
                                    add( DVDInventoryValueJRadioButton ); // add DVD inventory value button to JFrame
                                    add( previousJRadioButton ); // add previous button to JFrame
                                    add( nextJRadioButton ); // add next button to JFrame
                                    
                                    // create logical relationship between JRadioButtons
                                    radioGroup = new ButtonGroup(); // create ButtonGroup
                                    radioGroup.add( DVDNumberJRadioButton ); // add DVD number to group
                                    radioGroup.add( DVDNameJRadioButton ); // add DVD name to group
                                    radioGroup.add( DVDStockAmountJRadioButton ); // add DVD stock amount to group
                                    radioGroup.add( DVDPriceJRadioButton ); // add DVD price to group
                                    radioGroup.add( DVDInventoryValueJRadioButton ); // add DVD inventory value to group
                                    radioGroup.add( previousJRadioButton ); // add previous to group
                                    radioGroup.add( nextJRadioButton ); // add next to group
                                    
                                    // create field objects
                                    DVDNumber = new number( "%d\n" );
                                    DVDName = new name( "%s\n" );
                                    DVDStockAmount = new amount( "%d\n" );
                                    DVDPrice = new price( "%d\n" );
                                    DVDInventoryValue = new value( "%d/n" );
                                    previous = new previous( "%d/n" );
                                    next = new next( "%d/n" );
                                    textField.setfield( DVDNumber ); // set initial field to DVD number
                                    
                                    // RadioButtonFrame constructor
                                    DVDNumberJRadioButton.addItemListener(
                                            new RadioButtonHandler( DVDNumber ) );
                                    DVDNameJRadioButton.addItemListener(
                                            new RadioButtonHandler( DVDName ) );
                                    DVDStockAmountJRadioButton.addItemListener(
                                            new RadioButtonHandler( DVDStockAmount ) );
                                    DVDPriceJRadioButton.addItemListener(
                                            new RadioButtonHandler( DVDPrice ) );
                                    DVDInventoryValueJRadioButton.addItemListener(
                                            new RadioButtonHandler( DVDInventoryValue ) );
                                    previousJRadioButton.addItemListener(
                                            new RadioButtonHandler( previous ) );
                                    nextJRadioButton.addItemListener(
                                            new RadioButtonHandler( next ) );
                                } // end RadioButtonFrame constructor
                            
                                // private inner class to handle radio button events
                                private class RadioButtonHandler implements ItemListener {
                                    private Field field; // field associated with this listener
                                    
                                    public RadioButtonHandler( Field f ) {
                                        field = f; // set the field of this listener
                                    } // end constructor RadioButtonHandler
                                    
                                    // handle radio button events
                                    public void itemStateChanged( ItemEvent event ) {
                                        textField.setField( field ); // set field of textField
                                    } // end method itemStateChanged
                                } // end private inner class RadioButtonHandler
                            } // end class RadioButtonFrame
                         // Testing RadioButtonFrame.
                      // import javax.swing.JFrame
                            
                            public class RadioButtonTest { // error is: illegal start of expression and ';' expected
                                public static void main( string [] args ) {
                                    RadioButtonFrame radioButtonFrame = new RadioButtonFrame();
                                    radioButtonFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
                                    radioButtonFrame.setSize( 300, 100 ); // set frame size
                                    radioButtonFrame.setVisible( true ); // display frame
                                } // end main
                            } // end class RadioButtonTest
                           
                            // Using class MouseMotionAdapter
                            import java.awt.Point;    // again all imports have error of illegal start of expression
                            import java.awt.Graphics;
                            import java.awt.event.MouseEvent;
                            import java.awt.event.MouseMotionAdapter;
                            import javax.swing.JPanel;
                            
                        
                            public class PaintPanel extends JPanel {  // illegal start of expression and ';' expected
                                private int pointCount = 0; // count number of points
                                
                                // array of 1000 java.awt.Point references
                                private Point points[] = new Point[ 10000 ];
                                
                                // set up GUI and register mouse event handler
                                public PaintPanel() {
                                    // handle frame mouse motion event
                                    addMouseMotionListener(
                                            
                                            new MouseMotionAdapter() // anonymous inner class
                                    {
                                        // store drag coordinates and repaint
                                        public void mouseDragged( MouseEvent event ) {
                                            if ( pointCount < points.length ) {
                                                points[ pointCount ] = event.getPoint(); // find point
                                                pointCount++; // increment number of points in array
                                                repaint(); // repaint JFrame
                                            } // end if
                                        } // end method mouseDragged
                                    } // end anonymous inner class
                                    ); // end call to addMouseMotionListener
                                } // end PaintPanel constructor
                                
                                // draw company logo in a 4-by4- bounding box at specified location on window
                                public void paintComponent( Graphics g ) {
                                    super.paintComponent( g ); // clears drawing area
                                    
                                    // draw all points in array
                                    for ( int i = 0; i < pointCount; i++ )
                                        g.fillLogo( points[ i ].x, points[ i ].y, 4, 4 );
                                } // end method paintComponent
                            } // end class PaintPanel
                            
                            // display result in a JOPtionPane message dialog
                            JOptionPane.showMessageDialog( null, "The DVD Number is",
                                    JOptionPane,PLAIN_MESSAGE );
                            JOptionPane.showMessageDialog( null, "The DVD Name is",
                                    JOptionPane,PLAIN_MESSAGE );
                            JOptionPane.showMessageDialog( null, "The Amount of DVDs in Stock is",
                                    JOptionPane,PLAIN_MESSAGE );
                            JOptionPane.showMessageDialog( null, "The DVD Price is",
                                    JOptionPane.PLAIN_MESSAGE );
                            JOptionPane.showMessageDialog( null, "The DVD Inventory Value is",
                                    JOptionPane.PLAIN_MESSAGE );
                            
                            // get cd artist data
                            System.out.println(
                                    "DVD information obtained by get methods: \n" );
                            System.out.printf( "%s %s\n", "DVD Name is",
                                    DVDArtist.getDVDName() );
                            System.out.printf( "%s %s\n", "DVD Number is",
                                    DVDArtist.getDVDNumber() );
                            System.out.print( "%s %.2f\n", "DVD Price is",
                                    DVDArtist.getDVDPrice() );
                            System.out.prinf( "%s %.2f\n", "DVD Restocking Fee Rate is",
                                    DVDArtist.getDVDRestockingFeeRate() );
                            System.out.printf( "%s %.2f\n", "DVD Inventory Value is",
                                    DVDArtist.getDVDInventoryValue() );
                            
                            DVDArtist.setDVDInventoryValue( 1000 ); // set inventory value
                            
                            System.out.printf( "\n%s:\n\n%s\n",
                                    "Updated DVD Information obtained by toString",
                                    DVDArtist.toString());
                        } // end else
                    } // end else
                } // end else
            } // end main
        } // end public class display
    } // end class DVDArtist
} // end class DVD Inventory Value