Databases
StackOverflow2013
Postsdbo
POArrays not properly sorting
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POArrays not properly sorting
    primarykey
    data
    text
    <p>Good afternoon. I have created an application for an introductory java course that allows a user to sort their DVD collection by title, studio, or year. The application also allows the user to add additional DVD's to their collection, thus enlarging their arrays. The code properly compiles, but there is clearly something wrong as the titles, studio, and years are mixing themselves up. To be clear, this code is from a textbook and is part of a lab that requires the use of the exact methods, packages, etc. that you see in the code. I'm not asking for advice on how to make the code more efficient (although that is welcome as I am learning), but specifically what is wrong with the code provided causing the "scramble". Here is the code I have:</p> <pre><code>import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.text.*; public class DVD extends JFrame implements ActionListener { // construct components JLabel sortPrompt = new JLabel("Sort by:"); JComboBox fieldCombo = new JComboBox(); JTextPane textPane = new JTextPane(); // initialize data in arrays String title[] = {"Casablanca", "Citizen Kane", "Singin' in the Rain", "The Wizard of Oz"}; String studio[] = {"Warner Brothers", "RKO Pictures", "MGM", "MGM"}; String year[] = {"1942", "1941", "1952", "1939"}; // construct instance of DVD public DVD() { super("Classics on DVD"); } // create the menu system public JMenuBar createMenuBar() { // create an instance of the menu JMenuBar mnuBar = new JMenuBar(); setJMenuBar(mnuBar); // construct and populate the File menu JMenu mnuFile = new JMenu("File", true); mnuFile.setMnemonic(KeyEvent.VK_F); mnuFile.setDisplayedMnemonicIndex(0); mnuBar.add(mnuFile); JMenuItem mnuFileExit = new JMenu("Exit"); mnuFileExit.setMnemonic(KeyEvent.VK_X); mnuFileExit.setDisplayedMnemonicIndex(1); mnuFile.add(mnuFileExit); mnuFileExit.setActionCommand("Exit"); mnuFileExit.addActionListener(this); // contruct and populate the Edit menu JMenu mnuEdit = new JMenu("Edit", true); mnuEdit.setMnemonic(KeyEvent.VK_E); mnuEdit.setDisplayedMnemonicIndex(0); mnuBar.add(mnuEdit); JMenuItem mnuEditInsert = new JMenuItem("Insert New DVD"); mnuEditInsert.setMnemonic(KeyEvent.VK_I); mnuEditInsert.setDisplayedMnemonicIndex(0); mnuEdit.add(mnuEditInsert); mnuEditInsert.setActionCommand("Insert"); mnuEditInsert.addActionListener(this); JMenu mnuEditSearch = new JMenu("Search"); mnuEditSearch.setMnemonic(KeyEvent.VK_R); mnuEditSearch.setDisplayedMnemonicIndex(3); mnuEdit.add(mnuEditSearch); JMenuItem mnuEditSearchByTitle = new JMenuItem("by Title"); mnuEditSearchByTitle.setMnemonic(KeyEvent.VK_T); mnuEditSearchByTitle.setDisplayedMnemonicIndex(3); mnuEditSearch.add(mnuEditSearchByTitle); mnuEditSearchByTitle.setActionCommand("title"); mnuEditSearchByTitle.addActionListener(this); JMenuItem mnuEditSearchByStudio = new JMenuItem("by Studio"); mnuEditSearchByStudio.setMnemonic(KeyEvent.VK_S); mnuEditSearchByStudio.setDisplayedMnemonicIndex(3); mnuEditSearch.add(mnuEditSearchByStudio); mnuEditSearchByStudio.setActionCommand("studio"); mnuEditSearchByStudio.addActionListener(this); JMenuItem mnuEditSearchByYear = new JMenuItem("by Year"); mnuEditSearchByYear.setMnemonic(KeyEvent.VK_Y); mnuEditSearchByYear.setDisplayedMnemonicIndex(3); mnuEditSearch.add(mnuEditSearchByYear); mnuEditSearchByYear.setActionCommand("year"); mnuEditSearchByYear.addActionListener(this); return mnuBar; } // create the content pane public Container createContentPane() { // populate the JComboBox fieldCombo.addItem("Title"); fieldCombo.addItem("Studio"); fieldCombo.addItem("Year"); fieldCombo.addActionListener(this); fieldCombo.setToolTipText("Click the drop-down arrow to display sort fields."); // construct and populate the north panel JPanel northPanel = new JPanel(); northPanel.setLayout(new FlowLayout()); northPanel.add(sortPrompt); northPanel.add(fieldCombo); // create the JTextPane and center panel JPanel centerPanel = new JPanel(); setTabsAndStyles(textPane); textPane = addTextToTextPane(); JScrollPane scrollPane = new JScrollPane(textPane); scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); scrollPane.setPreferredSize(new Dimension(500, 200)); centerPanel.add(scrollPane); // create Container and set attributes Container c = getContentPane(); c.setLayout(new BorderLayout(10,10)); c.add(northPanel,BorderLayout.NORTH); c.add(centerPanel,BorderLayout.CENTER); return c; } // method to create tab stops and set font styles protected void setTabsAndStyles(JTextPane textPane) { // create Tab Stops TabStop[] tabs = new TabStop[2]; tabs[0] = new TabStop(200, TabStop.ALIGN_LEFT, TabStop.LEAD_NONE); tabs[1] = new TabStop(350, TabStop.ALIGN_LEFT, TabStop.LEAD_NONE); TabSet tabset = new TabSet(tabs); // set Tab Style StyleContext tabStyle = StyleContext.getDefaultStyleContext(); AttributeSet aset = tabStyle.addAttribute(SimpleAttributeSet.EMPTY, StyleConstants.TabSet, tabset); textPane.setParagraphAttributes(aset, false); // set Font styles Style fontStyle = StyleContext.getDefaultStyleContext().getStyle(StyleContext.DEFAULT_STYLE); Style regular = textPane.addStyle("regular", fontStyle); StyleConstants.setFontFamily(fontStyle, "SansSerif"); Style s = textPane.addStyle("italic", regular); StyleConstants.setItalic(s, true); s = textPane.addStyle("bold", regular); StyleConstants.setBold(s, true); s = textPane.addStyle("large", regular); StyleConstants.setFontSize(s, 16); } // method to add new text to the JTextPane public JTextPane addTextToTextPane() { Document doc = textPane.getDocument(); try { // clear the previous text doc.remove(0, doc.getLength()); // insert title doc.insertString(0,"TITLE\tSTUDIO\tYEAR\n",textPane.getStyle("large")); // insert detail for (int j = 0; j&lt;title.length; j++) { doc.insertString(doc.getLength(), title[j] + "\t", textPane.getStyle("bold")); doc.insertString(doc.getLength(), studio[j] + "\t", textPane.getStyle("italic")); doc.insertString(doc.getLength(), year[j] + "\t", textPane.getStyle("regular")); } } catch(BadLocationException ble) { System.err.println("Couldn't insert text."); } return textPane; } // event to process user clicks public void actionPerformed(ActionEvent e) { String arg = e.getActionCommand(); // user clicks the sort by combo box if (e.getSource() == fieldCombo) { switch(fieldCombo.getSelectedIndex()) { case 0: sort(title); break; case 1: sort(studio); break; case 2: sort(year); break; } } // user clicks Exit on the File menu if (arg == "Exit") System.exit(0); // user clicks Insert New DVD on the Edit Menu if (arg == "Insert") { // accept new data String newTitle = JOptionPane.showInputDialog(null, "Please enter the new movie's title"); String newStudio = JOptionPane.showInputDialog(null, "Please enter the studio for " + newTitle); String newYear = JOptionPane.showInputDialog(null, "Please enter the year for " + newTitle); // enlarge arrays title = enlargeArray(title); studio = enlargeArray(studio); year = enlargeArray(year); // add new data to arrays title[title.length-1] = newTitle; studio[studio.length-1] = newStudio; year[year.length-1] = newYear; // call sort method sort(title); fieldCombo.setSelectedIndex(0); } // user clicks Title on the Search submenu if (arg == "title") search(arg, title); // user clicks Studio on the Search submenu if (arg == "studio") search(arg, studio); // user clicks Year on the Search submenu if (arg == "year") search(arg, year); } // method to enlarge an array by 1 public String[] enlargeArray(String[] currentArray) { String[] newArray = new String[currentArray.length + 1]; for (int i = 0; i&lt;currentArray.length; i++) newArray[i] = currentArray[i]; return newArray; } // method to sort arrays public void sort(String tempArray[]) { // loop ton control number of passes for (int pass = 1; pass &lt; tempArray.length; pass++) { for (int element = 0; element &lt; tempArray.length - 1; element++) if (tempArray[element].compareTo(tempArray[element + 1])&gt;0) { swap(title, element, element + 1); swap(studio, element, element + 1); swap(year, element, element + 1); } } addTextToTextPane(); } // method to swap two elements of an array public void swap(String swapArray[], int first, int second) { String hold; // temporary holding area for swap hold = swapArray[first]; swapArray[first] = swapArray[second]; swapArray[second] = hold; } public void search(String searchField, String searchArray[]) { try { Document doc = textPane.getDocument(); // assign text to document object doc.remove(0,doc.getLength()); // clear previous text // display column titles doc.insertString(0,"TITLE\tSTUDIO\tYEAR\n",textPane.getStyle("large")); // prompt user for search data String search = JOptionPane.showInputDialog(null, "Please enter the "+searchField); boolean found = false; // search arrays for (int i = 0; i&lt;title.length; i++) { if (search.compareTo(searchArray[i])==0) { doc.insertString(doc.getLength(), title[i] + "\t", textPane.getStyle("bold")); doc.insertString(doc.getLength(), studio[i] + "\t", textPane.getStyle("italic")); doc.insertString(doc.getLength(), year[i] + "\t", textPane.getStyle("regular")); found = true; } } if (found == false) { JOptionPane.showMessageDialog(null, "Your search produced no results.","No results found",JOptionPane.INFORMATION_MESSAGE); sort(title); } } catch(BadLocationException ble) { System.err.println("Couldn't insert text."); } } // main method executes at run time public static void main(String arg[]) { JFrame.setDefaultLookAndFeelDecorated(true); DVD f = new DVD(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setJMenuBar(f.createMenuBar()); f.setContentPane(f.createContentPane()); f.setSize(600,375); f.setVisible(true); } } </code></pre> <p>Here is a screenshot to give you a sense of what I mean be "scrambled". <img src="https://i.stack.imgur.com/xcSr2.png" alt="Scrambled Application"></p> <p>Obviously, all of the titles should be in the title column, studios in studio, and years in year.</p> <p>As always, I appreciate the guidance.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USJerry
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POArrays not properly sorting
      1. This table or related slice is empty.
      1. VTDownMod
    2. VO
      singulars
      1. POArrays not properly sorting
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload