我正试图弄清楚如何使用其他网站上的示例更改模型后更新表窗口。一切正常但我无法想象一旦表模型发生变化后如何刷新窗口。
编辑：我使用了Bell的建议并重新安排了一些内容，以便构造函数调用我的getmodel3方法来填充表。我以为我可以使用setmodel方法来更改模型并更新表，但它没有像我想的那样工作。这就是我的想法，但不会发生：main方法使用从getmodel3方法传递的模型创建表的新实例。setmodel方法，使用getmodel4中返回的模型将不同的数据加载到新模型中。实际发生的是，创建一个新实例并使用从getmodel3返回的模型，然后setmodel方法运行并从一组不同的数据更新模型变量，但表格没有没有表现出变化。
public class myTable extends JFrame
{
public volatile DefaultTableModel model = (DefaultTableModel) myTable.getmodel3();
public void setmodel(DefaultTableModel newModel)
{
this.model = newModel;
}
public myTable()
{
JTable table = new JTable( model );
JScrollPane scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
getContentPane().add( buttonPanel, BorderLayout.SOUTH );
}
public static void main(String[] args)
{
myTable frame = new myTable();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
frame.setmodel(getmodel4());
}
这里的getmodel3与getmodel4相同，只是它们指向不同数据的不同数据库文件。
public static DefaultTableModel getmodel3(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model;
}
答案 0 :(得分：0)
您可以使用table.getModel()使用现有模型，并使用table.setModel(yourModel)设置新/现有模型
DefaultTableModel model = (DefaultTableModel) table.getModel();
// do modification here
table.setModel(model);
答案 1 :(得分：0)
好吧，在你的一些帮助下，我终于明白了。 setModel因为1而无法正常工作，我尝试使用它的方法范围无法访问，2我尝试创建自己的setter setmodel但我不知道是什么我在做 ：）。
最后，我在一个更容易到达的地方初始化，所以我没有在其他方法中弄乱对象。这是在调用main时加载表的工作结果，之后我可以调用update方法重新加载它。谢谢你们的帮助。
public class able extends JFrame
{
//initialize here for easy access. getmodel3() is the model getter method and
//returns the defaultTableModel object
private static able frame = new able();
private static JTable table = new JTable( getmodel3() );
//Start all main stuff here using the previously initialized objects.
public static void main(String[] args)
{
JScrollPane scrollPane = new JScrollPane( table );
frame.getContentPane().add( scrollPane );
JPanel buttonPanel = new JPanel();
frame.getContentPane().add( buttonPanel, BorderLayout.SOUTH );
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
}
public static void update()
{
table.setModel(getmodel3());
}
//This method makes the table model from sql result set and returns it.
//(found online somewhere thanks to whoever wrote it)
public static DefaultTableModel getmodel3(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model3 = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model3;
}
public static DefaultTableModel getmodel4(){
Vector<Object> columnNames = new Vector<Object>();
Vector<Object> data = new Vector<Object>();
try
{
// Connect to an Access Database
String url = "jdbc:sqlite:c:\\sqlite3\\test2.db";
Connection conn = DriverManager.getConnection(url);
// Read data from a table
String sql = "Select * from Tasks";
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery( sql );
ResultSetMetaData md = rs.getMetaData();
int columns = md.getColumnCount();
// Get column names
for (int i = 1; i <= columns; i++)
{
columnNames.addElement( md.getColumnName(i) );
}
// Get row data
while (rs.next())
{
Vector<Object> row = new Vector<Object>(columns);
for (int i = 1; i <= columns; i++)
{
row.addElement( rs.getObject(i) );
}
data.addElement( row );
}
rs.close();
stmt.close();
conn.close();
}
catch(Exception e)
{
System.out.println( e );
}
// Create table with database data
DefaultTableModel model3 = new DefaultTableModel(data, columnNames)
{
@Override
public Class getColumnClass(int column)
{
for (int row = 0; row < getRowCount(); row++)
{
Object o = getValueAt(row, column);
if (o != null)
{
return o.getClass();
}
}
return Object.class;
}
};
System.out.println("got model");
return model3;
}
}