lib/jtar/org/kamranzafar/jtar/TarUtils.java

   1 /**
   2  * Copyright 2012 Kamran Zafar
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 package org.kamranzafar.jtar;
  19
  20 import java.io.File;
  21
  22 /**
  23  * @author Kamran
  24  *
  25  */
  26 public class TarUtils {
  27         /**
  28          * Determines the tar file size of the given folder/file path
  29          *
  30          * @param path
  31          * @return
  32          */
  33         public static long calculateTarSize(File path) {
  34                 return tarSize(path) + TarConstants.EOF_BLOCK;
  35         }
  36
  37         private static long tarSize(File dir) {
  38                 long size = 0;
  39
  40                 if (dir.isFile()) {
  41                         return entrySize(dir.length());
  42                 } else {
  43                         File[] subFiles = dir.listFiles();
  44
  45                         if (subFiles != null && subFiles.length > 0) {
  46                                 for (File file : subFiles) {
  47                                         if (file.isFile()) {
  48                                                 size += entrySize(file.length());
  49                                         } else {
  50                                                 size += tarSize(file);
  51                                         }
  52                                 }
  53                         } else {
  54                                 // Empty folder header
  55                                 return TarConstants.HEADER_BLOCK;
  56                         }
  57                 }
  58
  59                 return size;
  60         }
  61
  62         private static long entrySize(long fileSize) {
  63                 long size = 0;
  64                 size += TarConstants.HEADER_BLOCK; // Header
  65                 size += fileSize; // File size
  66
  67                 long extra = size % TarConstants.DATA_BLOCK;
  68
  69                 if (extra > 0) {
  70                         size += (TarConstants.DATA_BLOCK - extra); // pad
  71                 }
  72
  73                 return size;
  74         }
  75
  76         public static String trim(String s, char c) {
  77                 StringBuffer tmp = new StringBuffer(s);
  78                 for (int i = 0; i < tmp.length(); i++) {
  79                         if (tmp.charAt(i) != c) {
  80                                 break;
  81                         } else {
  82                                 tmp.deleteCharAt(i);
  83                         }
  84                 }
  85
  86                 for (int i = tmp.length() - 1; i >= 0; i--) {
  87                         if (tmp.charAt(i) != c) {
  88                                 break;
  89                         } else {
  90                                 tmp.deleteCharAt(i);
  91                         }
  92                 }
  93
  94                 return tmp.toString();
  95         }
  96 }