从ArrayList和Jlist中的相应索引中删除对象

Question

I have a class that reads a object file and imports it in an ArrayList. Then I made a Jlist to show some of the information of each objectfrom that ArrayList. So when they select an element of the Jlist, it will show the entire corresponding index object from the ArrayList. I want to add a "Delete" button to remove the selected Jlist element and the corresponding index object from the ArrayList. And then update the Jlist showing that element is deleted.

This is my class:

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import java.io.File;
import java.io.FileInputStream;
import java.io.ObjectInputStream;
import java.util.ArrayList;

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.ListModel;
import javax.swing.ListSelectionModel;
import javax.swing.SwingConstants;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.JScrollPane;
import javax.swing.JList;

import java.awt.TextArea;

import javax.swing.JTable;
import javax.swing.JTextPane;
import javax.swing.JTextArea;
import javax.swing.JComboBox;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JTextField;
import javax.swing.JButton;

import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;


public class LogBook2 extends JFrame {


    private static ArrayList<Log> logList = new ArrayList<Log>();



    private static String logs;



    private JPanel contentPane;
    private JScrollPane scrollPane;
    private JList list;
    private JScrollPane scrollPane_1;
    private String tpContent;

    private int diveNumber;
    private int diveDate;
    private String diveMonth;
    private int diveYear;
    private String location;
    private String diveSite;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    LogBook frame = new LogBook();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public LogBook2() {


        //===============================================================================
        //Importing form the Object file to ArrayList "logList" 
        File fileOfLogs=new File("logList.txt");
        if(fileOfLogs.exists()){
            try{
                ObjectInputStream myStream = new ObjectInputStream(new FileInputStream("logList.txt"));

                logList = (ArrayList<Log>) myStream.readObject();



                myStream.close();


            }
            catch(Exception e){
                setVisible(false);
                JOptionPane.showMessageDialog(null, " 00000 There was a problem while reading dive records.\n "
                        + "Please contact SEASFiRE Tech Team.", "Error", JOptionPane.ERROR_MESSAGE);

            }

        }
        else if(!fileOfLogs.exists()){
            JOptionPane.showMessageDialog(null, " 11111 There was a problem while reading dive records.\n "
                    + "Please contact SEASFiRE Tech Team.", "Error", JOptionPane.ERROR_MESSAGE);

        }
        //===============================================================================

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 888, 680);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);



        JScrollPane scrollPane_2 = new JScrollPane();
        scrollPane_2.setBounds(10, 88, 297, 542);
        contentPane.add(scrollPane_2);

        JList list_1 = new JList();
        scrollPane_2.setViewportView(list_1);
        list_1.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);


        //===============================================================================
        //getting some information of each object and making a Jlist element with it.
        DefaultListModel model=new DefaultListModel();
        for( int i=0;i<logList.size();i++){



            model.addElement(""+logList.get(i).getDiveNumber()+"__"+logList.get(i).getDiveDate()+"/"+logList.get(i).getDiveMonth()+"/"+logList.get(i).getDiveYear()
                    +"__"+logList.get(i).getLocation()+"_"+logList.get(i).getDiveSite());

        }

        list_1.setModel(model);


        //===============================================================================



        JLabel lblAddNewLog = new JLabel("Log Book");
        lblAddNewLog.setHorizontalAlignment(SwingConstants.CENTER);
        lblAddNewLog.setFont(new Font("Myanmar Text", Font.BOLD, 40));
        lblAddNewLog.setBounds(0, 16, 862, 61);
        contentPane.add(lblAddNewLog);



        scrollPane = new JScrollPane();
        scrollPane.setBounds(317, 88, 322, 542);
        contentPane.add(scrollPane);

        JTextArea textArea = new JTextArea();
        textArea.setEditable(false);
        scrollPane.setViewportView(textArea);
        JButton btnDelete = new JButton("Delete");
        //===============================================================================
        //trying to make the "Delete" button. Not working...
        btnDelete.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {


                model.remove(list_1.getSelectedIndex());
                list_1.remove(list_1.getSelectedIndex());
                textArea.setText("");
                list_1.clearSelection();






            }
        });
        btnDelete.setBounds(649, 561, 115, 29);
        contentPane.add(btnDelete);
        //========================================================================




        //========================================================================
        //the action for when an element is selected.
        list_1.addListSelectionListener(
                new ListSelectionListener(){
                    public void valueChanged(ListSelectionEvent event){
                        textArea.setText("");
                        textArea.append("Dive Number: "+logList.get(list_1.getSelectedIndex()).getDiveNumber()+"\t\tDive Date: "+
                    logList.get(list_1.getSelectedIndex()).getDiveDate()+"/"+logList.get(list_1.getSelectedIndex()).getDiveMonth()+
                    "/"+logList.get(list_1.getSelectedIndex()).getDiveYear()+"\n\nLocation: "+logList.get(list_1.getSelectedIndex()).getLocation()+
                    "\n\nDive Site: "+logList.get(list_1.getSelectedIndex()).getDiveSite()+"\n\nDive Type: "+logList.get(list_1.getSelectedIndex()).getDiveType()+
                    "\t\tCondition: "+logList.get(list_1.getSelectedIndex()).getCondition()+"\n\nVisibility: "+logList.get(list_1.getSelectedIndex()).getVisibility()+
                    "m\t\tSuit Type: "+logList.get(list_1.getSelectedIndex()).getSuitType()+"\n\nWeights: "+logList.get(list_1.getSelectedIndex()).getWeight()+
                    "m\t\tAltitude: "+logList.get(list_1.getSelectedIndex()).getAltitude()+"m\n\nTime In: "+logList.get(list_1.getSelectedIndex()).getHourIn()+
                    ":"+logList.get(list_1.getSelectedIndex()).getMinIn()+"\t\tDuration: "+logList.get(list_1.getSelectedIndex()).getDuration()+
                    "min\n\nMax Depth: "+logList.get(list_1.getSelectedIndex()).getMaxDepth()+"m\t\tSafety Stop: "+logList.get(list_1.getSelectedIndex()).getSafetyStop()+
                    "\n\nAir in: "+logList.get(list_1.getSelectedIndex()).getAirIn()+"bar\t\tAir Out: "+logList.get(list_1.getSelectedIndex()).getAirOut()+
                    "bar\n\n02 Perc: "+logList.get(list_1.getSelectedIndex()).getOxgPerc()+"%\t\tDive Buddy: "+logList.get(list_1.getSelectedIndex()).getDiveBuddy()+
                    "\n\nNote: "+logList.get(list_1.getSelectedIndex()).getNote());


                    }
                }
            );



        //========================================================================







    }
}

Answer 1

Don't keep a separate ArrayList to hold the data.

Instead all the data should be stored in the ListModel

DefaultListModel<Log> model = new DefaultListModel<Log>();
model.addElement(...);
JList<Log> list = new JList<Log>( model );

Then you create a custom renderer for the JList to display whatever data from the Log class that you want:

list.setCellRenderer( new DefaultListCellRenderer()
{
    public Component getListCellRendererComponent(
            JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
    {
        super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        Log log = (Log)value;
        setText( log.get...() ):
        return this;
    }
});

Now you only have data in one place so when you want to delete a row you just delete the row from the DefaultListModel.

If you want to know how to delete an entry from the ListModel then take a look at the section from the Swing tutorial on How to Use Lists . The "Fire" button will delete the selected row. The tutorial will also explain more about using a custom renderer.

Answer 2

add a toString() method to your Log class.

public void toString(){
    return "" + getDiveNumber()+"__"+getDiveDate()+"/"+getDiveMonth()+"/"+getDiveYear() +"__"+getLocation()+"_"+getDiveSite();
}

then add listmodel log instances

model.addElement(logList.get(i));