Passing object to excel spreadsheet

[Martin Lira]

Hi,
I have a jsp that calls a bean to get some data from the database. The bean returns an ArrayList. The jsp process the ArrayList and displays it in TABLE. I need to provide the user facility of viewing the same data in an excel spreadsheet. How can i pass this ArrayList object to another jsp page with the excel stuff. I dont want to use session.setAttribute. I tried using the request.setAttribute but since I make another request on submit I cannot retrieve by request.getAttribute.

Thanks,
Martin

[Dmitry Melnik]

Out of your ArrayList you can generate a text in "comma separated values" (or CSV) format, which is viewable via Excel. You might need to make the URL end with ".csv"

[Martin Lira]

Actually I have a Hashtable and not an ArrayList. The hash table contains key/value pair ("Date", ArrayListOfValueObjectForThatDate).

-Martin

[Dmitry Melnik]

It does not matter if you know how to make a .csv file out of it

[Martin Lira]

Dmitry,
I dont know how to create a .csv from Hashtable key,values. Any sample code will really help.

thanks,
Martin

[Dmitry Melnik]

This should give you a general idea, optimize it as appropriate.

 
    public static String hashToCSV(String headers, Hashtable hash) {
        StringBuffer sb = new StringBuffer(headers);
 
        for(Enumeration keys=hash.keys(); keys.hasMoreElements(); ) {
            Object key = keys.nextElement();
            List value = (List)hash.get(key);
            boolean quoted = false;
            StringBuffer line = new StringBuffer();
 
/*
// Uncomment this block if you need keys in the output
 
            String keyString = key.toString();
            quoted = keyString.indexOf(',')>=0;
            if(quoted) line.append('"');
            line.append(keyString);
            if(quoted) line.append('"');
*/
            for(Iterator i=value.iterator(); i.hasNext(); ) {
                if(line.length()>0) line.append(',');
                String valueString = i.next().toString();
                quoted = valueString.indexOf(',')>=0;
                if(quoted) line.append('"');
                line.append(valueString);
                if(quoted) line.append('"');
            }
            sb.append(line);
            sb.append('\n');
        }
 
        return sb.toString();
    }