Java tutorial
//package com.java2s; /** * Copyright 2016 JustWayward Team * <p> * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * <p> * http://www.apache.org/licenses/LICENSE-2.0 * <p> * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.text.DecimalFormat; public class Main { public static String formatFileSizeToString(long fileLen) { DecimalFormat df = new DecimalFormat("0.00"); String fileSizeString = ""; if (fileLen < 1024) { fileSizeString = df.format((double) fileLen) + "B"; } else if (fileLen < 1048576) { fileSizeString = df.format((double) fileLen / 1024) + "K"; } else if (fileLen < 1073741824) { fileSizeString = df.format((double) fileLen / 1048576) + "M"; } else { fileSizeString = df.format((double) fileLen / 1073741824) + "G"; } return fileSizeString; } }