下面是我从数据库创建表的代码。我想在最后添加一个不会在数据库中的复选框列。它只是前端的一部分。你能帮忙吗?
尽管选择了一行,但我的 getRow() 方法继续返回-1,有什么建议吗?
package Default;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.*;
import java.sql.*;
/**
* This class create JTable from Database table.
* User program needs to specify database connection and corresponding a table name.
*
*/
public class DBTable{
//private String table;
DefaultTableModel dm=new DefaultTableModel();
JTable t1=new JTable();
Object row[];
String c[];
int cols;
PreparedStatement pst;
ResultSet rs ;
public DBTable(Connection conn){
conn=Login.con;
}
/**
* This method return JTable object created from Database table having selected data and structur * as in original table into database.
* @param table Name of the database table to be coverted to JTable
* @param query Select query to specify selected columns and data to extracted from database table
* @return JTable object that consist of selected data and structure of Database table
* @throws java.lang.Exception Original object is deferent, e.i either SQLException or NullPointerException
*/
public JTable getTable(String table,String query)throws Exception{
JTable t1=new JTable();
DefaultTableModel dm=new DefaultTableModel();
Statement st= Login.con.createStatement();
ResultSet rs=st.executeQuery(query);
ResultSetMetaData rsmd=rs.getMetaData();
//Coding to get columns-
int cols=rsmd.getColumnCount();
String c[]=new String[cols];
for(int i=0;i<cols;i++){
c[i]=rsmd.getColumnName(i+1);
dm.addColumn(c[i]);
}
//get data from rows
Object row[]=new Object[cols];
while(rs.next()){
for(int i=0;i<cols;i++){
row[i]=rs.getString(i+1);
}
dm.addRow(row);
}
t1.setModel(dm);
return t1;
}
public int getRow(){
int row = t1.getSelectedRow();
JOptionPane.showMessageDialog(null, row);
return row;
}
public void deleteRow(String sql){
try {
String value = (String) t1.getValueAt(getRow(), 0);
JOptionPane.showMessageDialog(null, value);
pst = Login.con.prepareStatement(sql);
pst.setString(1, value);
((DefaultTableModel)t1.getModel()).removeRow(getRow());
pst.execute();
JOptionPane.showMessageDialog(null, "Deleted");
} catch (Exception e) {
e.printStackTrace();
JOptionPane.showMessageDialog(null, e);
}
}
}