On small stress getting Exhausted Resultset

[Dale Carnegie]

He,everybody!

My program works just fine for one user. But when I stress my application with 300 transactions per minute (avg 5/sec) i am getting an error (1 transaction of 300 failed).
When i stress with 1000 about 100 transactions are failed.
And I can't understand what's wrong.

The error:

java.sql.SQLException: Exhausted Resultset
        at oracle.jdbc.driver.OracleResultSetImpl.getString(OracleResultSetImpl.java:1091)
        at MyApp.selectSQL(MyApp.java:90)

Piece of code:

public static List selectSQL(String sql) {
		
		con= getConnection(login,password);
		
		List list = new ArrayList();
		
		try {
			Statement s = con.createStatement();
			ResultSet rs = s.executeQuery(sql);
			ResultSetMetaData rsmd = rs.getMetaData();
			int columns = rsmd.getColumnCount();

			List rec = new ArrayList();
			for (int i = 1; i <= columns; i++) {
				rec.add(rsmd.getColumnName(i));
			}
			
			list.add(rec);

			while (rs.next()) {
				rec = new ArrayList();
				for (int i = 1; i <= columns; i++) {
					rec.add(rs.getString(i));    // <- THIS IS 90s row where stack shows error
				}
				list.add(rec);
			}
			
			s.close();
			con.close();

			return list;

		} catch (SQLException e) {
			e.printStackTrace();
			
			try{
				con.close();
			}catch(Exception h){
			
			}
			
			
		}
		
	
		return list;
	}

Can't you tell me what may be wrong and how to troubleshoot this?

[Tom Reilly]

I assume that multiple threads can call the method you post. Can you post the implementation of getConnection()?