Cursor在AsyncTask的PreparedStatement上实现(Cursor implement on PreparedStatement in AsyncTask)

 所以我想实现一个光标到我的类，所以我可以填充我的数据网格（不知道这是否正确的方式来做到这一点，当我需要使用可调用SP和准备语句）得到一个 
 
 
 
 DataGridActivity.Itemnumber不是抽象的，并且不会覆盖Cursor中的抽象方法响应（Bundle） 
 
 
 我不知道如何实现这里的抽象方法，因为我正常使用getstring methode为我准备好的语句想知道是否有某种方式可以做到这一点，而不是使用光标填充我的网格 
 
public class Itemnumber extends AsyncTask<String,String,String> implements Cursor {
    String z = "";
    @Override
    protected void onPreExecute() {
    }
    @Override
    protected void onPostExecute(String r) {
    }

    @Override
    protected String doInBackground(String... params) {
        try {
            Connection con = connectionClass.CONN();
            if (con == null) {
                z = "Error in connection with SQL server";
            } else {
                PreparedStatement preparedStatement = null;
                String sqli = "select ID,ItemNumber,Trashed,Sold from [file].[Item] where [ItemNumber] =?";
                preparedStatement = con.prepareStatement(sqli);
                preparedStatement.setString(1, "test");
                ResultSet rs = preparedStatement.executeQuery();
                if (rs.next()) {
                } else {
                }
            }
        } catch (Exception ex) {
            z = "Exceptions";
        }
        return z;
    }
    @Override
    public Bundle respond(Bundle extras){
        moveToFirst();
        return Bundle.EMPTY;
    }
}
 
 
 我的Datagrid活动类 
 
Cursor csr = new Itemnumber();
//create DataTable object
DataTable dtDataSource = new DataTable();
//define column
dtDataSource.addAllColumns(new String[]{"column_1", "column_2","column_3", "column_4});
//create DataRow
DataTable.DataRow drRow;

//populate data from cursor into DataSource
if(csr.moveToFirst()){
    do{
        drRow = dtDataSource.newRow();
        drRow.set("column_1", csr.getString(csr.getColumnIndex("field_1")));
        drRow.set("column_2", csr.getString(csr.getColumnIndex("field_2")));
        drRow.set("column_2", csr.getString(csr.getColumnIndex("field_3")));
        drRow.set("column_4", csr.getString(csr.getColumnIndex("field_4")));

        dtDataSource.add(drRow);
    } while(csr.moveToNext());
    csr.close();
}        
/**
 *  Prepare the DataGrid
 */
//initialize DataGrid
DataGrid dg = (DataGrid)findViewById(R.id.datagrid);
//define column style, bond each DataGrid column by DataTable column
dg.addColumnStyles(new DataGrid.ColumnStyle[]{
        new DataGrid.ColumnStyle(getString(R.string.ID), "column_1", 80),
        new DataGrid.ColumnStyle(getString(R.string.ItemNumber), "column_2", 120),
        new DataGrid.ColumnStyle(getString(R.string.Trashed), "column_3", 100),
        new DataGrid.ColumnStyle(getString(R.string.Sold), "column_4", 150)    
});
//set the DataTable as source
dg.setDataSource(dtDataSource);
//generate the DataGrid
dg.refresh();

So I am trying to implement a Cursor to my class so i can populate my datagrid (not sure if that is the right way to do it when i need to use callable for SP and prepared statement) which i made from this guide here but i gets a 
 
 
 
DataGridActivity.Itemnumber is not abstract and does not override abstract method respond(Bundle) in Cursor
 
 
i am not sure how to implement the abstract method here as i normaly use getstring methode for my prepared statements wonder if there is somehow i could do that instead to populate my grid instead of using the Cursor
 
public class Itemnumber extends AsyncTask<String,String,String> implements Cursor {
    String z = "";
    @Override
    protected void onPreExecute() {
    }
    @Override
    protected void onPostExecute(String r) {
    }

    @Override
    protected String doInBackground(String... params) {
        try {
            Connection con = connectionClass.CONN();
            if (con == null) {
                z = "Error in connection with SQL server";
            } else {
                PreparedStatement preparedStatement = null;
                String sqli = "select ID,ItemNumber,Trashed,Sold from [file].[Item] where [ItemNumber] =?";
                preparedStatement = con.prepareStatement(sqli);
                preparedStatement.setString(1, "test");
                ResultSet rs = preparedStatement.executeQuery();
                if (rs.next()) {
                } else {
                }
            }
        } catch (Exception ex) {
            z = "Exceptions";
        }
        return z;
    }
    @Override
    public Bundle respond(Bundle extras){
        moveToFirst();
        return Bundle.EMPTY;
    }
}
 
 
My Datagrid activity class
 
Cursor csr = new Itemnumber();
//create DataTable object
DataTable dtDataSource = new DataTable();
//define column
dtDataSource.addAllColumns(new String[]{"column_1", "column_2","column_3", "column_4});
//create DataRow
DataTable.DataRow drRow;

//populate data from cursor into DataSource
if(csr.moveToFirst()){
    do{
        drRow = dtDataSource.newRow();
        drRow.set("column_1", csr.getString(csr.getColumnIndex("field_1")));
        drRow.set("column_2", csr.getString(csr.getColumnIndex("field_2")));
        drRow.set("column_2", csr.getString(csr.getColumnIndex("field_3")));
        drRow.set("column_4", csr.getString(csr.getColumnIndex("field_4")));

        dtDataSource.add(drRow);
    } while(csr.moveToNext());
    csr.close();
}        
/**
 *  Prepare the DataGrid
 */
//initialize DataGrid
DataGrid dg = (DataGrid)findViewById(R.id.datagrid);
//define column style, bond each DataGrid column by DataTable column
dg.addColumnStyles(new DataGrid.ColumnStyle[]{
        new DataGrid.ColumnStyle(getString(R.string.ID), "column_1", 80),
        new DataGrid.ColumnStyle(getString(R.string.ItemNumber), "column_2", 120),
        new DataGrid.ColumnStyle(getString(R.string.Trashed), "column_3", 100),
        new DataGrid.ColumnStyle(getString(R.string.Sold), "column_4", 150)    
});
//set the DataTable as source
dg.setDataSource(dtDataSource);
//generate the DataGrid
dg.refresh();

原文：https://stackoverflow.com/questions/41642997