java – Jtable行删除

public final class UserPage extends JFrame implements ActionListener {

    private AllUser userModel;
    private JTable uTable;
    JButton deleteUser;
    int selectedRow;

    public UserPage() {
        titleUserCount();
        userModel = new AllUser();
        uTable = new JTable(userModel);
        add(new JScrollPane(uTable),BorderLayout.CENTER);
        add(buttonPanels(),BorderLayout.PAGE_START);
        this.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        this.setSize(800,600);
        this.setLocation(300,60);
        this.setResizable(false);
    }   

    public final JPanel buttonPanels() {
        JPanel buttonsPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        deleteUser = new JButton("Delete User");

        deleteUser.addActionListener(this);
        buttonsPanel.add(deleteUser);

        return buttonsPanel;
    }   

    public void titleUserCount() {
        AllUser userCount = new AllUser();
        UserPage.this.setTitle("All User Information,Number Of user is : " + userCount.getRowCount());
    }   

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == deleteUser) {
            int selectedrow = uTable.getSelectedRow();
            if (selectedrow >= 0) {
                userModel.RemoveRow(selectedrow);
                titleUserCount();
            } else {
                JOptionPane.showMessageDialog(null,"No Row Selected");
            }   
        }   
    }   
}

public class AllUser extends AbstractTableModel {

    UserInformation uiS = new UserInformation();
    String[] col = {"ID","Fname","Lname","Gender","Date"};
    ArrayList<UserInformation> Udata = new ArrayList<UserInformation>();

    public AllUser() {
        BufferedReader br = null;
        try {
            FileReader fr = new FileReader("AllUserRecords.txt");
            br = new BufferedReader(fr);
            String line;
            while ((line = br.readLine()) != null) {
                if (line.trim().length() == 0) {
                    continue;
                }
                Udata.add(initializeUserInfos(line));
            }
        } catch (IOException e) {
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException ioe) {
                }
            }
        }
    }

    private UserInformation initializeUserInfos(String str) {
        UserInformation Uinit = new UserInformation();
        String[] CellArray = str.split("     ");
        Uinit.setID(CellArray[0]);
        Uinit.setFname(CellArray[1]);
        Uinit.setLname(CellArray[2]);
        Uinit.setGender(CellArray[3]);
        Uinit.setDate(CellArray[4]);
        return Uinit;
    }

    public void RemoveRow(int rowIndex) {
        if (RemoveUserFromFile(rowIndex)) {
            Udata.remove(rowIndex);
            fireTableRowsDeleted(rowIndex,rowIndex);
        } else {
            JOptionPane.showMessageDialog(null,"Unable to delete");
        }
    }

    public boolean RemoveUserFromFile(int index) {
        File Mf = new File("AllUserRecords.txt");
        File Tf = new File("Uoutput.txt");
        try {
            BufferedReader Ubr = new BufferedReader(new FileReader(Mf));
            PrintWriter Upw = new PrintWriter(new FileWriter(Tf));
            String line;
            while ((line = Ubr.readLine()) != null) {
                if (line.trim().length() == 0) {
                    continue;
                }
                if (!line.startsWith(String.valueOf(getValueAt(index,0)))) {
                    Upw.println(line);
                }
            }
            Upw.close();
            Ubr.close();
            Mf.delete();
            Tf.renameTo(Mf);
            return true;
        } catch (FileNotFoundException e1) {
            return false;
        } catch (IOException ioe) {
            return false;
        }
    }

    @Override
    public String getColumnName(int colu) {
        return col[colu];
    }

    @Override
    public int getRowCount() {
        return Udata.size();
    }

    @Override
    public int getColumnCount() {
        return col.length;
    }

    @Override
    public Object getValueAt(int rowIndex,int columnIndex) {
        UserInformation uinfoS = Udata.get(rowIndex);
        Object value = null;
        switch (columnIndex) {
            case 0:
                value = uinfoS.getID();
                break;
            case 1:
                value = uinfoS.getFname();
                break;
            case 2:
                value = uinfoS.getLname();
                break;
            case 3:
                value = uinfoS.getGender();
                break;
            case 4:
                value = uinfoS.getDate();
                break;
            default:
                value = "...";
        }
        return value;
    }

    @Override
    public void setValueAt(Object value,int rowIndex,int columnIndex) {
        UserInformation userInfo = Udata.get(rowIndex);

        switch (columnIndex) {

            case 0:
                userInfo.setID((String) value);
                break;
            case 1:
                userInfo.setFname((String) value);
                break;
            case 2:
                userInfo.setLname((String) value);
                break;
            case 3:
                userInfo.setGender((String) value);
                break;
            case 4:
                userInfo.setDate((String) value);
                break;
        }
    }
}

public class UserInformation {

    private String Fname;
    private String Lname;
    private String ID;
    private String Gender;
    private String Date;

    public String getFname() {
        return Fname;
    }

    public void setFname(String fname) {
        this.Fname = fname;
    }

    public String getLname() {
        return Lname;
    }

    public void setLname(String lname) {
        this.Lname = lname;
    }

    public String getID() {
        return ID;
    }

    public void setID(String i_d) {
        this.ID = i_d;
    }

    public String getGender() {
        return Gender;
    }

    public void setGender(String gndr) {
        this.Gender = gndr;
    }

    public String getDate() {
        return Date;
    }

    public void setDate(String date) {
        this.Date = date;
    }

    @Override
    public String toString() {
        return ID + "     " + Fname + "     "
                + Lname + "     " + Gender + "     " + Date + "n";
    }
}

85     lo     ii     Female     2013/03/08
86     jkj     nmn     Female     2013/03/08
52     tyr     fgfg     Female     2013/03/08
7     dfdf     wew     Female     2013/03/08
47     zczc     asa     Female     2013/03/08
16     erw     www     Male     2013/03/08
83     gfg     dsd     Male     2013/03/08

好吧,既然我没有你的所有代码,所以我正在进行一个虚拟程序,用于从JTable中删除记录以及相应的文件.观察MyTabeModel类中定义的removeRow方法.它还涵盖了从ArrayList删除记录后无法将数据写入文件(records.temp)的风险.

import javax.swing.table.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import java.util.*;
import java.io.*;
public class TableFocus extends JFrame 
{
    MyTableModel model1;
    JTable table1;
    public void createAndShowGUI()
    {
        setTitle("JTables");
        Container c  = getContentPane();
        model1 = new MyTableModel();
        table1 = new JTable(model1);
        table1.setColumnSelectionAllowed(false);
        table1.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        JScrollPane jsTable1 = new JScrollPane(table1);
        c.add(jsTable1);
        JButton button = new JButton("Delete");
        button.addActionListener( new ActionListener()
        {
            public void actionPerformed(ActionEvent evt)
            {
                if (model1.getRowCount() > 0 && table1.getSelectedRow() != -1 )
                {
                    model1.deleteRow(table1.getSelectedRow());
                }
            }
        });
        add(button,BorderLayout.SOUTH);
        setSize(500,300);
        setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    private class MyTableModel extends AbstractTableModel
    {
        String columns[] ;
        ArrayList<ArrayList<String>> data;
        public MyTableModel()
        {
            columns = new String[] {"Roll No.","Name"};
            prepareData();
        }
        private void prepareData()
        {
            data = new ArrayList<ArrayList<String>>();
            data.add(new ArrayList<String>(){{add("1");add("Michael");}});
            data.add(new ArrayList<String>(){{add("2");add("Derake");}});
            data.add(new ArrayList<String>(){{add("3");add("Archie");}});
        }
        @Override
        public String getColumnName(int columnIndex)
        {
            return columns[columnIndex];
        }
        @Override
        public int getRowCount()
        {
            return data.size();
        }
        @Override 
        public int getColumnCount()
        {
            return columns.length;
        }
        @Override
        public Object getValueAt(int row,int col)
        {
            return data.get(row).get(col);
        }
        @Override
        public void setValueAt(Object aValue,int colIndex)
        {
            data.get(rowIndex).set(colIndex,(String)aValue);
            fireTableCellUpdated(rowIndex,colIndex);
        }
        @Override
        public boolean isCellEditable(int row,int col)
        {
            return false;
        }
        public void deleteRow(int row)
        {
            ArrayList<String> temp = data.get(row);//backup of value in case of IOException while writing to file
            BufferedWriter bfr = null;
            try
            {
                data.remove(row);
                //Write here the logic for repopulating file with new records.
                bfr = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("records.temp")));
                StringBuffer sBuffer = new StringBuffer();
                for (ArrayList<String> list : data)
                {
                    StringBuffer buf = new StringBuffer();
                    for (String val : list )
                    {
                        buf.append(val+"t");
                    }
                    buf.replace(buf.length() - 1,buf.length(),"n");
                    sBuffer.append(buf.toString());
                }
                bfr.write(sBuffer.toString());
                bfr.flush();
                bfr.close();
                fireTableRowsDeleted(row,row);
            }
            catch (Exception ex)
            {
                data.add(row,temp);//Rollback the delete from ArrayList
                ex.printStackTrace();
            }
            finally
            {
                if (bfr != null)
                {
                    try
                    {
                        bfr.close();
                    }
                    catch (Exception ex){}
                }
            }

        }
    }
    public static void main(String[] args) 
    {
        SwingUtilities.invokeLater( new Runnable()
        {
            @Override
            public void run()
            {
                TableFocus ths = new TableFocus();
                ths.createAndShowGUI();
            }
        });
    }
}

UPDATE

Sometimes when i select a row in my table and click to delete button,
more that one line has been deleted!

在完成您的代码之后,我了解了删除多行的情况.情况是：如果文件中有多行,则从您要删除的记录的相同用户ID开始.
例如,假设您的文件中有这样的条目：

85     lo     ii     Female     2013/03/08
86     jkj     nmn     Female     2013/03/08
52     tyr     fgfg     Female     2013/03/08
86     jkj     pqr     Male      2013/03/08
7     dfdf     wew     Female     2013/03/08
47     zczc     asa     Female     2013/03/08
16     erw     www     Male     2013/03/08
83     gfg     dsd     Male     2013/03/08

这里userID 86包含在两行中(第2行和第4行).当您在JTable中选择第4行以删除该特定记录时,它会从您的文件中删除第2行和第4行.但在JTable中,第二行将继续显示,因为直到现在它都没有使用新文件刷新.只要用新文件刷新JTable,它就会显示从那里删除的行.
要知道它为什么会发生,请看看你的RemoveUserFromFile(int index)方法while循环,如下所示：

while ((line = Ubr.readLine()) != null) //Reads the file till the end.
{
  if (line.trim().length() == 0) {
    continue;
  }
  if (!line.startsWith(String.valueOf(getValueAt(index,0)))) //If line starts with 86 don't write it to new `Uoutput.txt`. so all lines starting with 86 will be ignored.
  {
     Upw.println(line);//Lines starting with 86 is not written.
   }
 }

我希望你现在有充分的理由知道为什么有时从JTable中删除一条记录会从你的文件中删除两行或两行以上.
解决此问题的方法是以下列方式更改方法(RemoveRow和RemoveUserFromFile):(使用此修改后的代码)

public void RemoveRow(int rowIndex) {
    UserInformation temp = Udata.get(rowIndex);//Keep it as back up so that you could reconsolidate it to ArrayList in case RemoveUserFromFile return false
    Udata.remove(rowIndex);//remove the element from Udata on temporary basis.
    if (RemoveUserFromFile(rowIndex)) 
    {
          fireTableRowsDeleted(rowIndex,rowIndex);
    } 
    else 
    {
        Udata.add(rowIndex,temp);//re-insert temp in ArrayList as the file updation is failed.
        JOptionPane.showMessageDialog(null,"Unable to delete");
    }
}

public boolean RemoveUserFromFile(int index) 
{
    File Mf = new File("AllUserRecords.txt");
    File Tf = new File("Uoutput.txt");
    PrintWriter Upw = null;
    try 
    {
        Upw = new PrintWriter(new FileWriter(Tf));
        for (UserInformation uino : Udata )
        {
            Upw.print(uino.toString());//Don't use Upw.println because the toString() method of UserInformation class is already using n in last.
        }
        Upw.close();
        Mf.delete();
        Tf.renameTo(Mf);
        return true;
    } catch (FileNotFoundException e1) {
        return false;
    } catch (IOException ioe) {
        return false;
    }
    finally 
    {
        if (Upw != null)
        {
            try
            {
                Upw.close();
            }
            catch (Exception ex){}
        }
    }
}

我希望现在能解决你的问题……

注意：作为旁注.我想建议你在编写代码时坚持使用java命名约定.例如：类名始终以大写字母开头.变量名称始终以小写字母开头.常数(即最终变量)的所有字母都是大写的.还有很多其他的.看看oracle的official site.