樹節點狀態的保存和加載

保存樹節點狀態至數據庫表中
this.addWindowListener(new WindowAdapter() {
    public void windowClosing(WindowEvent e) {
        String rows = "";
        TreePath rootPath = new TreePath(((TreeNode) tree.getModel().getRoot()));
        Enumeration enums = tree.getExpandedDescendants(rootPath);
        while (enums != null && enums.hasMoreElements()) {
            TreePath path = (TreePath) enums.nextElement();
            int row = tree.getRowForPath(path);
            rows += "," + row;
        }
        rows = (rows.startsWith(",") ? rows.substring(1) : rows);


        TreePath path  = tree.getSelectionPath();                
        int selectedRow = tree.getLeadSelectionRow();

        String sql = "if ((select count(1) from CompanyStatus where loginUser='"+ loginUser +"')>0) "  
                     + "update CompanyStatus set expandedRow='" + rows + "', selectedRow=" + selectedRow + " where loginUser='"+ loginUser +"'" 
                     + " else insert into CompanyStatus (loginUser, expandedRow, selectedRow) values('"+ loginUser +"','" + rows + "'," + selectedRow + ")";
        execute(sql);
    }
});

從數據庫中加載樹的狀態
public static void initCompanyStatus(JTree tree) {
    int selectedRow = -1;
    String[] expandedRow = {""};
    String sql = "select expandedRow, selectedRow from CompanyStatus where loginUser='"+ loginUser +"'";
    QueryDataSet dataset = executeQuery(sql);
    if(dataset.getRowCount() > 0) {
        expandedRow = dataset.getString("expandedRow").split(",");
        selectedRow = dataset.getInt("selectedRow");
    }

    for(int i=0; i<tree.getRowCount(); i++) {
        for(int j=0; j<expandedRow.length; j++) {
            if(expandedRow[j].equals("" + i)) {
                tree.expandRow(i);
                break;
            }
        }
    }

    tree.setSelectionRow(selectedRow);
}