java-是否可以在JTable中的指定列上侦听数据更改？
作者：互联网
我正在用一种类似于excel的公式进行JTable,因为某些单元格是自动计算的.
我正在使用TableModelListener侦听数据更改,并在那里调用一个函数以遍历所有数据并计算每一行的值,如下所示.
我正在计算列号3“ uds”,它包含由colum件给出的整数.例如,如果件的值为“ 3”,则uds应该为“ 1”,或者如果件的值为“ 3-5”,uds应该为“ 2”
private void maths() {
// 0 1 2 3 4
// Descrip - Pieces - PVP - Uds - Total - Done
// Col 4 is Nº of "-" (col2 * col3)
int colDescrip = 0; int colPieces = 1; int colPvp = 2; int colUds = 3; int colTotal = 4; //Columnas
for(int row = 0; row < getTable().getRowCount(); row++) {
String pieces = getTable().getModel().getValueAt(row, colPiezas).toString();
if(pieces != "") {
Integer n = nOfHyphens(getTable().getModel().getValueAt(row, colPieces).toString());
System.out.println(n);
getTable().getModel().setValueAt(n, row, colUds); //Error here
}
System.out.println("Col 0: " + getTable().getModel().getValueAt(row, 0) + "." + getTable().getModel().getValueAt(row, 0).getClass());
System.out.println("Col 1: " + getTable().getModel().getValueAt(row, 1) + "." + getTable().getModel().getValueAt(row, 1).getClass());
System.out.println("Col 2: " + getTable().getModel().getValueAt(row, 2) + "." + getTable().getModel().getValueAt(row, 2).getClass());
System.out.println("Col 3: " + getTable().getModel().getValueAt(row, 3) + "." + getTable().getModel().getValueAt(row, 3).getClass());
System.out.println("Col 4: " + getTable().getModel().getValueAt(row, 4) + "." + getTable().getModel().getValueAt(row, 4).getClass());
System.out.println("#################");
}
}
private int nOfHyphens(String s) {
int t = 1;
char c = '-';
for(int i = 0; i < s.length(); i++)
if(s.charAt(i) == c)
t++;
return t;
}
此maths()函数在public void tableChanged(TableModelEvent arg0)内部调用,而我的问题是,每次它计算每一行的总数时,数据都会发生变化,当然,该事件一次又一次地调用,直到得到StackOverflowError,如何我可以预防吗？用数据制作一个JTable,用结果制作另一个JTable？还是只有在指定的列更改时才可以调用此事件？
谢谢.
编辑：添加完整代码
public class PresupuestoFrameNuevo extends JFrame{
private JPanel tableHolder;
private JPanel btnHolder;
private JPanel btnleft;
private JPanel btnright;
private JScrollPane jsp;
private JTable table;
private JButton addrow;
private JButton delrow;
private JButton save;
private JButton cancel;
private ButtonListener BL;
private TableListener TL;
public static void main(String args[]) {
new PresupuestoFrameNuevo();
}
public PresupuestoFrameNuevo() {
setSize(1000,600);
setTitle("Presupuesto nuevo");
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setLocationRelativeTo(null);
setLayout(new BorderLayout());
initComps();
drawComps();
setVisible(true);
}
private void initComps() {
setTable(new JTable(new PresupuestoModel()));
setJsp(new JScrollPane(getTable()));
getTable().getTableHeader().setReorderingAllowed(false);
getTable().getTableHeader().setResizingAllowed(false);
getTable().setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
getTable().setCellSelectionEnabled(true);
setTL(new TableListener());
getTable().getModel().addTableModelListener(getTL());
//Table width
getTable().getColumnModel().getColumn(0).setPreferredWidth(300); //Descrip
getTable().getColumnModel().getColumn(2).setMaxWidth(80);//pvp unidad
getTable().getColumnModel().getColumn(3).setMaxWidth(70);//unidades
getTable().getColumnModel().getColumn(4).setMaxWidth(80);//total
getTable().getColumnModel().getColumn(5).setMaxWidth(60);//hecho
setTableHolder(new JPanel());
setBtnHolder(new JPanel());
setBtnleft(new JPanel());
setBtnright(new JPanel());
getTableHolder().setLayout(new GridLayout(1,1));
getBtnHolder().setLayout(new GridLayout(1,2));
setBL(new ButtonListener());
setAddrow(new JButton("Add row"));
setDelrow(new JButton("Delete row")); //TODO
setSave(new JButton("Save")); //TODO
setCancel(new JButton("Cancel")); //TODO
getAddrow().addActionListener(getBL());
getDelrow().addActionListener(getBL());
getSave().addActionListener(getBL());
getCancel().addActionListener(getBL());
}
private void drawComps() {
getBtnleft().add(getAddrow());
getBtnleft().add(getDelrow());
getBtnright().add(getSave());
getBtnright().add(getCancel());
getBtnleft().setBorder(BorderFactory.createTitledBorder("Tools"));
getBtnright().setBorder(BorderFactory.createTitledBorder("Options"));
getTableHolder().add(getJsp());
getBtnHolder().add(getBtnleft());
getBtnHolder().add(getBtnright());
add(getBtnHolder(), BorderLayout.SOUTH);
add(getTableHolder(), BorderLayout.CENTER);
}
private class ButtonListener implements ActionListener{
@Override
public void actionPerformed(ActionEvent ae) {
if(ae.getSource() == addrow) {
((PresupuestoModel) getTable().getModel()).addRow();
}
else if(ae.getSource() == delrow) {
}
else if(ae.getSource() == save) {
}
else if(ae.getSource() == cancel) {
}
}
}
private class TableListener implements TableModelListener{
@Override
public void tableChanged(TableModelEvent e) {
System.out.println(e.getSource());
System.out.println(e.getSource().getClass());
System.out.println(e.getColumn());
/*if(e.getColumn() == 3) {
return;
}
else {
//maths();
}*/
}
private void maths() {
// 0 1 2 3 4
// Descrip - Piezas - PVP Unidad - Unidades - Total - Hecho
// Nº of "-" 2*3
int colDescrip = 0; int colPieces = 1; int colPvp = 2; int colUds = 3; int colTotal = 4; //Columnas
for(int row = 0; row < getTable().getRowCount(); row++) {
String pie = getTable().getModel().getValueAt(row, colPieces).toString();
if(pie != "") {
Integer n = nOfHyphens(getTable().getModel().getValueAt(row, colPieces).toString());
System.out.println(n);
getTable().getModel().setValueAt(n, row, colUds);
}
System.out.println("Col 0: " + getTable().getModel().getValueAt(row, 0) + "." + getTable().getModel().getValueAt(row, 0).getClass());
System.out.println("Col 1: " + getTable().getModel().getValueAt(row, 1) + "." + getTable().getModel().getValueAt(row, 1).getClass());
System.out.println("Col 2: " + getTable().getModel().getValueAt(row, 2) + "." + getTable().getModel().getValueAt(row, 2).getClass());
System.out.println("Col 3: " + getTable().getModel().getValueAt(row, 3) + "." + getTable().getModel().getValueAt(row, 3).getClass());
System.out.println("Col 4: " + getTable().getModel().getValueAt(row, 4) + "." + getTable().getModel().getValueAt(row, 4).getClass());
System.out.println("#################");
}
}
private int nOfHyphens(String s) {
int t = 1;
char c = '-';
for(int i = 0; i < s.length(); i++)
if(s.charAt(i) == c)
t++;
return t;
}
}
public JPanel getTableHolder() {
return tableHolder;
}
public void setTableHolder(JPanel tableHolder) {
this.tableHolder = tableHolder;
}
public JPanel getBtnHolder() {
return btnHolder;
}
public void setBtnHolder(JPanel btnHolder) {
this.btnHolder = btnHolder;
}
public JPanel getBtnleft() {
return btnleft;
}
public void setBtnleft(JPanel btnleft) {
this.btnleft = btnleft;
}
public JPanel getBtnright() {
return btnright;
}
public void setBtnright(JPanel btnright) {
this.btnright = btnright;
}
public JScrollPane getJsp() {
return jsp;
}
public void setJsp(JScrollPane jsp) {
this.jsp = jsp;
}
public JTable getTable() {
return table;
}
public void setTable(JTable table) {
this.table = table;
}
public JButton getAddrow() {
return addrow;
}
public void setAddrow(JButton addrow) {
this.addrow = addrow;
}
public JButton getDelrow() {
return delrow;
}
public void setDelrow(JButton delrow) {
this.delrow = delrow;
}
public JButton getSave() {
return save;
}
public void setSave(JButton save) {
this.save = save;
}
public JButton getCancel() {
return cancel;
}
public void setCancel(JButton cancel) {
this.cancel = cancel;
}
public ButtonListener getBL() {
return BL;
}
public void setBL(ButtonListener bL) {
BL = bL;
}
public TableListener getTL() {
return TL;
}
public void setTL(TableListener tL) {
TL = tL;
}
}
表格模型
public class PresupuestoModel extends AbstractTableModel {
private String[] cols = { "Description", "Pieces", "PVP U", "Uds", "Total", "Done" };
private Vector<Object[]> data;
public PresupuestoModel() {
setData(new Vector<Object[]>());
}
public void addRow() {
Object[] s = new Object[getCols().length];
for (int i = 0; i < getCols().length; i++) {
if (i != getCols().length - 1)
s[i] = "";
else
s[i] = new Boolean(false);
}
getData().add(s);
fireTableRowsInserted(getRowCount() - 1, getColumnCount());
}
public void deleteRow(int index) {
getData().remove(index);
fireTableRowsDeleted(index, index);
}
public String getColumnName(int n) {
return getCols()[n];
}
public boolean isCellEditable(int row, int col) {
if ((col == 3) || (col == 4))
return false;
else
return true;
}
public Class<?> getColumnClass(int c) {
if (c == getCols().length - 1) {
return Boolean.class;
}
else if((c == 2) || (c == 3)) {
return Integer.class;
}
else {
return String.class;
}
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
return (getData().get(rowIndex))[columnIndex];
}
public void setValueAt(Object value, int row, int col) {
System.out.println("Object: " + value + "." + value.getClass()+ "[" + row + "," + col + "]");
if(col == getCols().length - 1) {
(getData().get(row))[col] = value;
}
else if((col > 1) || (col < 5)) {
(getData().get(row))[col] = value;
}
else {
(getData().get(row))[col] = value.toString();
}
fireTableDataChanged();
}
@Override
public int getColumnCount() {
return getCols().length;
}
@Override
public int getRowCount() {
return getData().size();
}
public String[] getCols() {
return cols;
}
public void setCols(String[] cols) {
this.cols = cols;
}
public Vector<Object[]> getData() {
return data;
}
public void setData(Vector<Object[]> data) {
this.data = data;
}
}
解决方法:
TableModelEvent参数具有getColumn()方法,该方法将告诉您正在更改并导致事件的列.您可以使用if块,检查此方法返回的int值,如果忽略了列,则只需调用return即可；
public void tableChanged(TableModelEvent event) {
if (event.getColumn() == COLUMN_TO_IGNORE) {
return;
} else {
maths();
}
}
标签：stack-overflow,listener,swing,jtable,java 来源： https://codeday.me/bug/20191027/1945077.html