ByteSizeFormat


1   /*
2    * Copyright (c) 2001 - 2005 ivata limited.
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4    * -----------------------------------------------------------------------------
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29   * -----------------------------------------------------------------------------
30   * $Log: ByteSizeFormat.java,v $
31   * Revision 1.3  2005/04/11 16:54:15  colinmacleod
32   * Changed HTMLFormat to an interface (rather
33   * than an abstract class.)
34   *
35   * Revision 1.2  2005/04/09 17:19:59  colinmacleod
36   * Changed copyright text to GPL v2 explicitly.
37   *
38   * Revision 1.1.1.1  2005/03/10 17:51:35  colinmacleod
39   * Restructured ivata op around Hibernate/PicoContainer.
40   * Renamed ivata groupware.
41   *
42   * Revision 1.1  2004/09/30 15:16:01  colinmacleod
43   * Split off addressbook elements into security subproject.
44   *
45   * Revision 1.3  2004/03/21 21:16:08  colinmacleod
46   * Shortened name to ivata op.
47   *
48   * Revision 1.2  2004/02/01 22:00:33  colinmacleod
49   * Added full names to author tags
50   *
51   * Revision 1.1.1.1  2004/01/27 20:57:55  colinmacleod
52   * Moved ivata openportal to SourceForge..
53   *
54   * Revision 1.1.1.1  2003/10/13 20:50:09  colin
55   * Restructured portal into subprojects
56   *
57   * Revision 1.2  2003/06/19 07:46:41  jano
58   * fixing bug with int size
59   *
60   * Revision 1.1  2003/02/24 19:33:32  colin
61   * moved to jsp
62   *
63   * Revision 1.2  2003/02/04 17:43:46  colin
64   * copyright notice
65   *
66   * Revision 1.1  2002/09/18 16:34:46  colin
67   * first version used in email list
68   * -----------------------------------------------------------------------------
69   */
70  package com.ivata.groupware.web.format;
71  
72  import com.ivata.mask.util.StringHandling;
73  import com.ivata.mask.web.format.HTMLFormat;
74  
75  
76  /**
77   * <p>Format the size of a file or other object as bytes, kb, or Mb
78   * depending if the number is less than a kilobyte, or less than a
79   * megabyte in size..</p>
80   *
81   * @since 2002-09-18
82   * @author Colin MacLeod
83   * <a HREF='mailto:colin.macleod@ivata.com'>colin.macleod@ivata.com</a>
84   * @version $Revision: 1.3 $
85   */
86  public class ByteSizeFormat implements HTMLFormat {
87      /**
88       * <p>The size under which the number appears just as it is, a raw
89       * number. If the numer is greater than this size (but less than
90       * <code>megaSize</code>) it will be displayed as a multiple of this
91       * number.</p>
92       */
93      static final int kiloSize = 1024;
94      /**
95       * <p>The size above which the number appears as a multiple of this
96       * number, a multiple of <i>megabytes</i>.</p>
97       */
98      static final int megaSize = 1048576;
99      /**
100      * <p>The number of decimal places to show for <i>kilobyte</i> or
101      * <i>megabyte</i> sizes.</p>
102      */
103     private int decimals = 1;
104     /**
105      * <p>String to append to the number if it is expressed in
106      * <i>bytes</i>.</p>
107      */
108     private String   byteUnits = "";
109     /**
110      * <p>String to append to the number if it is expressed in
111      * <i>kilobytes</i>.</p>
112      */
113     private String   kiloUnits = "k";
114     /**
115      * <p>String to append to the number if it is expressed in
116      * <i>Megabytes</i>.</p>
117      */
118     private String   megaUnits = "M";
119     /**
120      * <p>The character to use as a decimal point.</p>
121      */
122     private char decimalCharacter = '.';
123 
124     /**
125      * <p>Convert  the number the given string represents according to
126      * whether or not the number represents just <i>bytes</i>,
127      * <i>kilobytes</i> or <i>megabytes<i>.</p>
128      *
129      * @param byteTextParam string number to convert.
130      * @return a string representing the size, expressed in the
131      * appropriate units.
132      */
133     public String   format(final String   byteTextParam) {
134         // first convert the string to an integer
135         Integer   bytesInteger = StringHandling.integerValue(byteTextParam);
136         int bytes;
137         String   byteText = byteTextParam;
138         if(bytesInteger == null) {
139             bytes = 0;
140         } else {
141             bytes = bytesInteger.intValue();
142         }
143         // is this less than the kilo size?
144         if(bytes < kiloSize) {
145             byteText = bytes + byteUnits;
146         } else {
147             // both the kilo and mega ranges need to do rounding
148             int rounding = 10;
149             for(int exp = 0; exp < decimals; ++exp) {
150                 rounding *= 10;
151             }
152             long newValue = (long) bytes * rounding;
153             String   units;
154             // if this is in the kilo range, divide by that amount
155             if(bytes < megaSize) {
156                 newValue /= kiloSize;
157                 units = kiloUnits;
158             } else {
159                 newValue /= megaSize;
160                 units = megaUnits;
161             }
162             // the clever bit - this does the rounding up or down whichever is
163             // nearest
164             newValue += 5;
165             newValue /= 10;
166 
167             // now to add the decimal point
168             String   noDecimal = Long.toString(newValue);
169             int length = noDecimal.length();
170             byteText = noDecimal.substring(0, length - decimals)
171                 + decimalCharacter
172                 + noDecimal.substring(length - decimals)
173                 + units;
174         }
175         return byteText;
176     }
177 
178     /**
179      * <p>The number of decimal places to show for <i>kilobyte</i> or
180      * <i>megabyte</i> sizes.</p>
181      *
182      * @return the current value of decimal places.
183      */
184     public final int getDecimals() {
185         return decimals;
186     }
187 
188     /**
189      * <p>The number of decimal places to show for <i>kilobyte</i> or
190      * <i>megabyte</i> sizes.</p>
191      *
192      * @param decimals the new value of decimal places to display.
193      */
194     public final void setDecimals(final int decimals) {
195         this.decimals = decimals;
196     }
197 
198     /**
199      * <p>String to append to the number if it is expressed in
200      * <i>bytes</i>.</p>
201      *
202      * @return the current value of byte units.
203      */
204     public final String   getByteUnits() {
205         return byteUnits;
206     }
207 
208     /**
209      * <p>String to append to the number if it is expressed in
210      * <i>bytes</i>.</p>
211      *
212      * @param byteUnits the new value of units to append to numbers
213      * expressed in bytes.
214      */
215     public final void setByteUnits(final String   byteUnits) {
216         this.byteUnits = byteUnits;
217     }
218 
219     /**
220      * <p>String to append to the number if it is expressed in
221      * <i>kilobytes</i>.</p>
222      *
223      * @return the current value of kilo units.
224      */
225     public final String   getKiloUnits() {
226         return kiloUnits;
227     }
228 
229     /**
230      * <p>String to append to the number if it is expressed in
231      * <i>kilobytes</i>.</p>
232      *
233      * @param kiloUnits the new value of units to append to numbers
234      * expressed in kilobytes.
235      */
236     public final void setKiloUnits(final String   kiloUnits) {
237         this.kiloUnits = kiloUnits;
238     }
239 
240     /**
241      * <p>String to append to the number if it is expressed in
242      * <i>Megabytes</i>.</p>
243      *
244      * @return the current value of mega units.
245      */
246     public final String   getMegaUnits() {
247         return megaUnits;
248     }
249 
250     /**
251      * <p>String to append to the number if it is expressed in
252      * <i>Megabytes</i>.</p>
253      *
254      * @param megaUnits the new value of units to append to numbers
255      * expressed in megabytes.
256      */
257     public final void setMegaUnits(final String   megaUnits) {
258         this.megaUnits = megaUnits;
259     }
260 
261     /**
262      * <p>The character to use as a decimal point.</p>
263      *
264      * @return the current value of decimal character.
265      */
266     public final char getDecimalCharacter() {
267         return decimalCharacter;
268     }
269 
270     /**
271      * <p>The character to use as a decimal point.</p>
272      *
273      * @param decimalCharacter the new value of decimal character.
274      */
275     public final void setDecimalCharacter(final char decimalCharacter) {
276         this.decimalCharacter = decimalCharacter;
277     }
278 }
279
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