Java tutorial
//package com.java2s; /* * GeoTools - The Open Source Java GIS Toolkit * http://geotools.org * * (C) 2005-2008, Open Source Geospatial Foundation (OSGeo) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ public class Main { /** * Given an array of objects, traverses the array and determines the most * suitable data type to perform the calculation in. An empty object of * the correct class is returned; * * @param objects * */ static Object getObject(Object[] objects) { Class bestClass = bestClass(objects); if (bestClass == String.class) { return new String(""); //$NON-NLS-1$ } else if (bestClass == Double.class) { return new Double(0); } else if (bestClass == Float.class) { return new Float(0); } else if (bestClass == Long.class) { return new Long(0); } else if (bestClass == Integer.class) { return new Integer(0); } else { //it's a type we don't have here yet return null; } } /** * Determines the most appropriate class to use for a multiclass calculation. * * @param objects * @return the most */ static Class bestClass(Object[] objects) { boolean hasInt = false; boolean hasFloat = false; boolean hasLong = false; boolean hasDouble = false; boolean hasString = false; for (int i = 0; i < objects.length; i++) { if (objects[i] instanceof Double) { hasDouble = true; } else if (objects[i] instanceof Float) { hasFloat = true; } else if (objects[i] instanceof Long) { hasLong = true; } else if (objects[i] instanceof Integer) { hasInt = true; } else if (objects[i] instanceof String) { hasString = true; } } if (hasString) { return String.class; } else if (hasDouble) { return Double.class; } else if (hasFloat) { return Float.class; } else if (hasLong) { return Long.class; } else if (hasInt) { return Integer.class; } else { //it's a type we don't have here yet return null; } } }