Home » Android » json – android Cursor to JSONArray

json – android Cursor to JSONArray

Posted by: admin June 15, 2020 Leave a comment

Questions:

how can I “convert” a Cursor to a JSONArray?

my cursor as 3columns (_id, name, birth)

I’ve searched but I can’t not find any examples

How to&Answers:

You can’t convert the contents of a cursor directly into a JSONObject, but you can do that with some logic.

for eg: retrieve the Strings from the cursor, form a String which follows the JSON format, and use it to make a json object :

JSONObject jFromCursor=new JSONObject(string_in_JSON_format);

Answer:

Cursor to JSONArray

public JSONArray cur2Json(Cursor cursor) {

    JSONArray resultSet = new JSONArray();
    cursor.moveToFirst();
    while (cursor.isAfterLast() == false) {
        int totalColumn = cursor.getColumnCount();
        JSONObject rowObject = new JSONObject();   
        for (int i = 0; i < totalColumn; i++) {
            if (cursor.getColumnName(i) != null) {
                try {
                    rowObject.put(cursor.getColumnName(i),
                            cursor.getString(i));
                } catch (Exception e) {
                    Log.d(TAG, e.getMessage());
                }
            }
        }
        resultSet.put(rowObject);
        cursor.moveToNext();
    }

    cursor.close();
    return resultSet;

}

Answer:

private String cursorToString(Cursor crs) {
    JSONArray arr = new JSONArray();
    crs.moveToFirst();
    while (!crs.isAfterLast()) {
        int nColumns = crs.getColumnCount();
        JSONObject row = new JSONObject();
        for (int i = 0 ; i < nColumns ; i++) {
            String colName = crs.getColumnName(i);
            if (colName != null) {
                String val = "";
                try {
                    switch (crs.getType(i)) {
                    case Cursor.FIELD_TYPE_BLOB   : row.put(colName, crs.getBlob(i).toString()); break;
                    case Cursor.FIELD_TYPE_FLOAT  : row.put(colName, crs.getDouble(i))         ; break;
                    case Cursor.FIELD_TYPE_INTEGER: row.put(colName, crs.getLong(i))           ; break;
                    case Cursor.FIELD_TYPE_NULL   : row.put(colName, null)                     ; break;
                    case Cursor.FIELD_TYPE_STRING : row.put(colName, crs.getString(i))         ; break;
                    }
                } catch (JSONException e) {
                }
            }
        }
        arr.put(row);
        if (!crs.moveToNext())
            break;
    }
    crs.close(); // close the cursor
    return arr.toString();
}