Here you can find the source of getDouble(ResultSet resultSet, int columnIndex)
public static Double getDouble(ResultSet resultSet, int columnIndex) throws SQLException
//package com.java2s; //License from project: Open Source License import java.sql.ResultSet; import java.sql.SQLException; public class Main { public static Double getDouble(ResultSet resultSet, int columnIndex) throws SQLException { double value = resultSet.getDouble(columnIndex); return resultSet.wasNull() ? null : value; }/*from ww w. j a va 2 s . c o m*/ }