Java Swing JTable数据收集在最后一个单元上失败

Question

I am trying to collect data from a JTable by using the method below to an array.

public String[][] getTableData (JTable table) {
    DefaultTableModel dtm = (DefaultTableModel) table.getModel();
    int nRow = dtm.getRowCount(), nCol = dtm.getColumnCount();      
    String[][] tableData = new String[nRow][nCol];
    for (int i = 0 ; i < nRow ; i++)
        for (int j = 0 ; j < nCol ; j++)
            tableData[i][j] = (String) dtm.getValueAt(i,j);
    return tableData;
}

Everything works fine but I am not able to get data of the last row last column. No error is given. When I change the loop range, I get an arrayoutBound error.

The method that returns is below:

public void setGrid(String data [][], String header []){
    dtm.setRowCount(0);
    dtm.setColumnCount(0);
    dtm.setDataVector(data, header);
    tbl1.getColumnModel().getColumn(0).setPreferredWidth(25);
}

I have edited the method like as below to get the data captured.

public String[][] getTableData (JTable table) {
    String dat= new String();
    DefaultTableModel dtm = (DefaultTableModel) table.getModel();
    int nRow = dtm.getRowCount(), nCol = dtm.getColumnCount();
    String[][] tableData = new String[nRow][nCol];
    for (int i = 0 ; i < nRow ; i++)
        for (int j = 0 ; j < nCol ; j++)
            dat=dat + (String) dtm.getValueAt(i,j);
            bb.Toplabel.setText("data is :" +dat);
            //tableData[i][j] = (String) dtm.getValueAt(i,j);
    return tableData;
}

The data displayed is null even though the cell has value.

Answer 1

You had it almost right but forgot to store dat in the array. Also casting object to the String doesn't make it String. Better way is to get String by toString() method or simply treat Object as String in other operator like plus(+). Here is right and simplified code:

public String[][] getTableData (JTable table) {
    DefaultTableModel dtm = (DefaultTableModel) table.getModel();
    int nRow = dtm.getRowCount(), nCol = dtm.getColumnCount();
    String[][] tableData = new String[nRow][nCol];
    for (int i = 0 ; i < nRow ; i++)
        for (int j = 0 ; j < nCol ; j++) {
            String dat=""+ dtm.getValueAt(i,j);// this will be always the String
            bb.Toplabel.setText("data is :" +dat);
            tableData[i][j] = dat;
        }
    return tableData;
}

One more thing - always use curly braces in your code. Even for one line in the loop. It will help you avoid errors when you add more lines of the code to the loop body.