Using the request Object

To get all of the parameters available in the request object, and their values:

<%
  String[] params = request.getParameterValues();
  for (int i=0; i<params.length; i++)
  {
    String paramName = params[i];
    String paramValue = request.getParameter( paramName );
  }
%>

To obtain a record identifier from a request object sent by the platform:

<%
  String object_id = request.getParameter("object_id");
  String record_id = request.getParameter("record_id");
%>

Note: Although the object_id is alphanumeric, it can be used in any API that requires an object name.

To obtain a record identifier from a request object sent by a Custom Action button:

A Custom Action button can be applied to one record, or to several records at one time, if the user took advantage of the More Actions feature in the record list view. Because it can be applied to more than one record at a time, the process for obtaining record IDs differs somewhat.

Here is the code that does the job:

<%
    String object_id = request.getParameter("object_id");
    String selectedRecords = request.getParameter("selectedRecords"); 
    String filterCriteria = "";
    if (selectedRecords != null)
    {
		StringTokenizer st = new StringTokenizer(selectedRecords,",");
		while (st.hasMoreTokens())
		{
			if ( !"".equals(filterCriteria.trim()))
			{
				filterCriteria = " OR "
			}
			filterCriteria += "record_id = "+ st.nextToken();
		}
    }
    Result result;
    result = Functions.searchRecords(object_id , "record_id,name", filterCriteria);
    int resultCode = result.getCode();
    if (resultCode < 0)
    {
    }
    else if (resultCode == 0)
    {
        // No records found. Take action according to your business logic
    }
    else
    {
        //Records retrieved successfully
        ParametersIterator iterator = result.getIterator();
        while(iterator.hasNext())
        {
            Parameters params = iterator.next();
            String recordID = params.get("record_id");
            String recordName = params.get("name");
            // Take action according to your business logic
        }
    }
%>