1 /* ==================================================================== 2 * The Apache Software License, Version 1.1 3 * 4 * Copyright (c) 2000 The Apache Software Foundation. All rights 5 * reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 19 * 3. The end-user documentation included with the redistribution, 20 * if any, must include the following acknowledgment: 21 * "This product includes software developed by the 22 * Apache Software Foundation (http://www.apache.org/)." 23 * Alternately, this acknowledgment may appear in the software itself, 24 * if and wherever such third-party acknowledgments normally appear. 25 * 26 * 4. The names "Apache" and "Apache Software Foundation" must 27 * not be used to endorse or promote products derived from this 28 * software without prior written permission. For written 29 * permission, please contact apache@apache.org. 30 * 31 * 5. Products derived from this software may not be called "Apache", 32 * nor may "Apache" appear in their name, without prior written 33 * permission of the Apache Software Foundation. 34 * 35 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 36 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 37 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 38 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 39 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 40 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 41 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 42 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 43 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 44 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 45 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 46 * SUCH DAMAGE. 47 * ==================================================================== 48 * 49 * This software consists of voluntary contributions made by many 50 * individuals on behalf of the Apache Software Foundation. For more 51 * information on the Apache Software Foundation, please see 52 * <http://www.apache.org/>. 53 * 54 * Portions of this software are based upon public domain software 55 * originally written at the National Center for Supercomputing Applications, 56 * University of Illinois, Urbana-Champaign. 57 */ 58 59 package org.apache.poi.hpsf; 60 61 import java.util.*; 62 import org.apache.poi.hpsf.littleendian.*; 63 import org.apache.poi.hpsf.wellknown.*; 64 65 /** 66 * <p>Represents a section in a {@link PropertySet}.</p> 67 * 68 * @author Rainer Klute (klute@rainer-klute.de) 69 * @version $Id: Section.java,v 1.1 2002/02/14 04:00:59 mjohnson Exp $ 70 * @since 2002-02-09 71 */ 72 public class Section 73 { 74 75 /** 76 * <p>Maps property IDs to section-private PID strings. These 77 * strings can be found in the property with ID 0.</p> 78 */ 79 protected Map dictionary; 80 81 82 83 private ClassID formatID; 84 85 /** 86 * <p>Returns the format ID. The format ID is the "type" of the 87 * section.</p> 88 */ 89 public ClassID getFormatID() 90 { 91 return formatID; 92 } 93 94 95 96 private int offset; 97 98 /** 99 * <p>Returns the offset of the section in the stream.</p> 100 */ 101 public int getOffset() 102 { 103 return offset; 104 } 105 106 107 108 private int size; 109 110 /** 111 * <p>Returns the section's size in bytes.</p> 112 */ 113 public int getSize() 114 { 115 return size; 116 } 117 118 119 120 private int propertyCount; 121 122 /** 123 * <p>Returns the number of properties in this section.</p> 124 */ 125 public int getPropertyCount() 126 { 127 return propertyCount; 128 } 129 130 131 132 private Property[] properties; 133 134 /** 135 * <p>Returns this section's properties.</p> 136 */ 137 public Property[] getProperties() 138 { 139 return properties; 140 } 141 142 143 144 /** 145 * <p>Creates a {@link Section} instance from a byte array.</p> 146 * 147 * @param src Contains the complete property set stream. 148 * 149 * @param offset The position in the stream that points to the 150 * section's format ID. 151 */ 152 public Section(final byte[] src, int offset) 153 { 154 /* Read the format ID. */ 155 formatID = new ClassID(src, offset); 156 offset += ClassID.LENGTH; 157 158 /* Read the offset from the stream's start and positions to 159 * the section header. */ 160 this.offset = new DWord(src, offset).intValue(); 161 offset = this.offset; 162 163 /* Read the section length. */ 164 size = new DWord(src, offset).intValue(); 165 offset += DWord.LENGTH; 166 167 /* Read the number of properties. */ 168 propertyCount = new DWord(src, offset).intValue(); 169 offset += DWord.LENGTH; 170 171 /* Read the properties. The offset is positioned at the first 172 * entry of the property list. */ 173 properties = new Property[propertyCount]; 174 for (int i = 0; i < properties.length; i++) 175 { 176 final int id = new DWord(src, offset).intValue(); 177 offset += DWord.LENGTH; 178 179 /* Offset from the section. */ 180 final int sOffset = new DWord(src, offset).intValue(); 181 offset += DWord.LENGTH; 182 183 /* Calculate the length of the property. */ 184 int length; 185 if (i == properties.length - 1) 186 length = src.length - this.offset - sOffset; 187 else 188 length = 189 new DWord(src, offset + DWord.LENGTH).intValue() - sOffset; 190 191 /* Create it. */ 192 properties[i] = 193 new Property(id, src, this.offset + sOffset, length); 194 } 195 196 /* Extract the dictionary (if available). */ 197 dictionary = (Map) getProperty(0); 198 } 199 200 201 202 /** 203 * <p>Returns the value of the property with the specified ID. If 204 * the property is not available, <code>null</code> is returned 205 * and a subsequent call to {@link #wasNull} will return 206 * <code>true</code>.</p> 207 */ 208 protected Object getProperty(final int id) 209 { 210 wasNull = false; 211 for (int i = 0; i < properties.length; i++) 212 if (id == properties[i].getID()) 213 return properties[i].getValue(); 214 wasNull = true; 215 return null; 216 } 217 218 219 220 /** 221 * <p>Returns the value of the numeric property with the specified 222 * ID. If the property is not available, 0 is returned. A 223 * subsequent call to {@link #wasNull} will return 224 * <code>true</code> to let the caller distinguish that case from 225 * a real property value of 0.</p> 226 */ 227 protected int getPropertyIntValue(final int id) 228 { 229 final Integer i = (Integer) getProperty(id); 230 if (i != null) 231 return i.intValue(); 232 else 233 return 0; 234 } 235 236 237 238 private boolean wasNull; 239 240 /** 241 * <p>Checks whether the property which the last call to {@link 242 * #getPropertyIntValue} or {@link #getProperty} tried to access 243 * was available or not. This information might be important for 244 * callers of {@link #getPropertyIntValue} since the latter 245 * returns 0 if the property does not exist. Using {@link 246 * #wasNull} the caller can distiguish this case from a property's 247 * real value of 0.</p> 248 * 249 * @return <code>true</code> if the last call to {@link 250 * #getPropertyIntValue} or {@link #getProperty} tried to access a 251 * property that was not available, else <code>false</code>. 252 */ 253 public boolean wasNull() 254 { 255 return wasNull; 256 } 257 258 259 260 /** 261 * <p>Returns the PID string associated with a property ID. The ID 262 * is first looked up in the {@link Section}'s private 263 * dictionary. If it is not found there, the method calls {@link 264 * SectionIDMap#getPIDString}.</p> 265 */ 266 public String getPIDString(final int pid) 267 { 268 String s = null; 269 if (dictionary != null) 270 s = (String) dictionary.get(new Integer(pid)); 271 if (s == null) 272 s = SectionIDMap.getPIDString(getFormatID().getBytes(), pid); 273 if (s == null) 274 s = SectionIDMap.UNDEFINED; 275 return s; 276 } 277 278 } 279