[英]java refresh JTable when query changed
我正在構建一個SQL DB GUI。 我遇到的問題是,當用戶從SHOW TABLES雙擊表時,它不會更新顯示新表結果的表。
這是我的代碼:
JTabbedPane tabbedPane = new JTabbedPane();
Statement stat = Gui.getStat();
private JPanel panel;
private String query;
public static void main(String[] args) {
showTables();
}
public void showTables() throws SQLException{
ResultSet showTablesResult = null;
query = "abc";
try {
showTablesResult = stat.executeQuery("SHOW TABLES");
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, "Error connecting to databse");
}
displayResultSet(showTablesResult);
}
public void displayResultSet(ResultSet rs) throws SQLException{
JTable table = new JTable(buildTableModel(rs)){
private static final long serialVersionUID = 1L;
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
panel.add(new JScrollPane(table));
table.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent e){
if(e.getClickCount() == 2){
if(query == "abc"){
//get value in selected cell
String selectedData = null;
int[] selectedRow = table.getSelectedRows();
int[] selectedColumns = table.getSelectedColumns();
for (int i = 0; i < selectedRow.length; i++) {
for (int j = 0; j < selectedColumns.length; j++) {
selectedData = (String) table.getValueAt(selectedRow[i], selectedColumns[j]);
}
}
try {
viewTable(selectedData);
} catch (SQLException e1) {
e1.printStackTrace();
}
}
}
}
});
}
public void viewTable(String tName) throws SQLException{
ResultSet showTablesResult = null;
query = "123";
try {
showTablesResult = stat.executeQuery("SELECT * FROM " +tName);
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, "Error connecting to databse");
}
displayResultSet(showTablesResult);
}
public static DefaultTableModel buildTableModel(ResultSet rs)
throws SQLException {
ResultSetMetaData metaData = rs.getMetaData();
Vector<String> columnNames = new Vector<String>();
int columnCount = metaData.getColumnCount();
for (int column = 1; column <= columnCount; column++) {
columnNames.add(metaData.getColumnName(column));
}
Vector<Vector<Object>> data = new Vector<Vector<Object>>();
while (rs.next()) {
Vector<Object> vector = new Vector<Object>();
for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
vector.add(rs.getObject(columnIndex));
}
data.add(vector);
}
return new DefaultTableModel(data, columnNames);
}
我該如何解決這個問題使其起作用? 我認為可能有一個重繪或刷新表之類的函數,但我找不到它。
謝謝 :)
panel.add(new JScrollPane(table));
默認情況下,組件的大小為(0,0),因此無需繪制任何內容。
從可見的GUI添加(或刪除)組件時,您需要調用布局管理器,以便在面板上為組件指定大小/位置。 基本代碼是:
panel.add(...);
panel.revalidate();
panel.repaint();
但是,當使用邏輯“刷新”表時,這樣做容易得多:
table.setModel( your updated TableModel );
無需每次都重新創建JScrollPane和JTable。
正如camickr所說,不需要每次都重新創建JTable和TableModel
我會這樣做:
從viewTable(...)方法中刪除displayResultSet(...),只需將其替換為以下內容:
Vector<Vector<Object>> newDataVector = //fill with new data
defaultTableModel.setDataVector(newDataVector, columnIdentifiers);
defaultTableModel.fireTableDataChanged();
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