问题描述

java连接数据库 更新JTable问题

//下面是我的table
class Store_table

{
Object data[][];
Object name[]={"商品编号","商品名称","价格","上架日期","保质日期","库存"};
Store_table(String bq)
{

String url = "jdbc:sqlserver://127.0.0.1:1433;databaseName=Store;IntegratedSecurity=True";//
// Declare the JDBC objects.
Connection con=null;
Statement sql=null;
ResultSet rs=null; 

try {
    // Establish the connection.
    Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
    con = DriverManager.getConnection(url);    

    sql = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
    rs = sql.executeQuery("SELECT  * FROM 仓库 where 标签='"+bq+"'");
    rs.last();
    data=new Object[rs.getRow()][6];
    // Iterate through the data in the result set and display it.
    int i=0;
    rs.beforeFirst();
    while (rs.next()) {    

        long number=rs.getLong("商品编号");
        String name=rs.getString("商品名称");
        float price=rs.getFloat("价格");
        Date date=rs.getDate("上架日期");
        int staydate=rs.getInt("保质日期");
        int repertory=rs.getInt("库存");
        data[i][0]=number;
        data[i][1]=name;
        data[i][2]=price;
        data[i][3]=date;
        data[i][4]=staydate;
        data[i][5]=repertory;
        i++;

    }
}    

// Handle any errors that may have occurred.
catch (Exception e) {
    e.printStackTrace();    

}    

finally {
    if (rs != null)
        try {
            rs.close();
        } catch (Exception e) {
        }
    if (sql != null)
        try {
            sql.close();
        } catch (Exception e) {
        }
    if (con != null)
        try {
            con.close();
        } catch (Exception e) {
        }
} 

}

}

//我用JComboBox调用和更新JTable

        public void actionPerformed(ActionEvent arg0) {

            String a=comboBox.getSelectedItem().toString();

            store=new Store_table(a);
            //把store放进JTable
            ta=new JTable(store.data,store.name)
            {
                public boolean isCellEditable(int row, int column) {return false;};//设置列表数据不能修改
                };
            //把ta列表放进滚动列表
                ta.setModel(model);
            JScrollPane jsp=new JScrollPane(ta);
            //JScrollPane jsp=new JScrollPane(store);
            //getContentPane().add(jsp,BorderLayout.CENTER);
            ta.setBackground(Color.ORANGE);
            jsp.setBackground(Color.GRAY);
            //jsp.setBackground(Color.ORANGE);
            contentPane.add(jsp);
            jsp.setBounds(0, 41, 743, 252);

        }
    });

怎么让JTable在JComboBox改动的时候更新呢？
据说需要setModel 再repaint 再updateUI
可是具体怎么做呢？

解决方案

table不用每次都重新new一个，每次刷新用的都是同一个table, 所以new Jtable是在JComboBox的actionPerformed()之外，在动作之内只需更新table的model并repaint和updateUI. 你可以每次刷新都新建一个model:
DefaultTableModel model=new DefaultTableModel(store.data, store.name);
table.setModel(model);
table.repaint();
table.updateUI();
或者新建一个model类，在Store_table(String bq)里面将数据用list的方式保存：
public class StoreTableModel extends AbstractTableModel{

private String[] names = {"商品编号","商品名称","价格","上架日期","保质日期","库存"};
private List<Object> list = new ArrayList<Object>();

public StoreTableModel() {

}

public void setRowData(List list) {
    this.list = list;
    fireTableDataChanged();
}

@Override
public int getRowCount() {
    if(list.isEmpty())
        return -1;
    return list.size();
}

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

@Override
public String getColumnName(int columnIndex) {
    return names[columnIndex];
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    if (!list.isEmpty()) {
         return list.get(rowIndex)[columnIndex];
   }
    return null;
}

public boolean isCellEditable(int rowIndex, int columnIndex) {
    return false;
}

}