| 1 | package org.apache.velocity.runtime.resource; |
| 2 | |
| 3 | /* |
| 4 | * Copyright 2001,2004 The Apache Software Foundation. |
| 5 | * |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | */ |
| 18 | |
| 19 | import org.apache.velocity.runtime.RuntimeServices; |
| 20 | import org.apache.velocity.runtime.RuntimeConstants; |
| 21 | |
| 22 | import org.apache.velocity.runtime.resource.loader.ResourceLoader; |
| 23 | |
| 24 | import org.apache.velocity.exception.ResourceNotFoundException; |
| 25 | import org.apache.velocity.exception.ParseErrorException; |
| 26 | |
| 27 | /** |
| 28 | * This class represent a general text resource that |
| 29 | * may have been retrieved from any number of possible |
| 30 | * sources. |
| 31 | * |
| 32 | * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a> |
| 33 | * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| 34 | * @version $Id: Resource.java,v 1.12.4.1 2004/03/03 23:23:01 geirm Exp $ |
| 35 | */ |
| 36 | public abstract class Resource |
| 37 | { |
| 38 | protected RuntimeServices rsvc = null; |
| 39 | |
| 40 | /** |
| 41 | * The template loader that initially loaded the input |
| 42 | * stream for this template, and knows how to check the |
| 43 | * source of the input stream for modification. |
| 44 | */ |
| 45 | protected ResourceLoader resourceLoader; |
| 46 | |
| 47 | /** |
| 48 | * The number of milliseconds in a minute, used to calculate the |
| 49 | * check interval. |
| 50 | */ |
| 51 | protected static final long MILLIS_PER_SECOND = 1000; |
| 52 | |
| 53 | /** |
| 54 | * How often the file modification time is checked (in seconds). |
| 55 | */ |
| 56 | protected long modificationCheckInterval = 0; |
| 57 | |
| 58 | /** |
| 59 | * The file modification time (in milliseconds) for the cached template. |
| 60 | */ |
| 61 | protected long lastModified = 0; |
| 62 | |
| 63 | /** |
| 64 | * The next time the file modification time will be checked (in |
| 65 | * milliseconds). |
| 66 | */ |
| 67 | protected long nextCheck = 0; |
| 68 | |
| 69 | /** |
| 70 | * Name of the resource |
| 71 | */ |
| 72 | protected String name; |
| 73 | |
| 74 | /** |
| 75 | * Character encoding of this resource |
| 76 | */ |
| 77 | protected String encoding = RuntimeConstants.ENCODING_DEFAULT; |
| 78 | |
| 79 | /** |
| 80 | * Resource might require ancillary storage of some kind |
| 81 | */ |
| 82 | protected Object data = null; |
| 83 | |
| 84 | /** |
| 85 | * Default constructor |
| 86 | */ |
| 87 | public Resource() |
| 88 | { |
| 89 | } |
| 90 | |
| 91 | public void setRuntimeServices( RuntimeServices rs ) |
| 92 | { |
| 93 | rsvc = rs; |
| 94 | } |
| 95 | |
| 96 | /** |
| 97 | * Perform any subsequent processing that might need |
| 98 | * to be done by a resource. In the case of a template |
| 99 | * the actual parsing of the input stream needs to be |
| 100 | * performed. |
| 101 | * |
| 102 | * @return Whether the resource could be processed successfully. |
| 103 | * For a {@link org.apache.velocity.Template} or {@link |
| 104 | * org.apache.velocity.runtime.resource.ContentResource}, this |
| 105 | * indicates whether the resource could be read. |
| 106 | * @exception ResourceNotFoundException Similar in semantics as |
| 107 | * returning <code>false</code>. |
| 108 | */ |
| 109 | public abstract boolean process() |
| 110 | throws ResourceNotFoundException, ParseErrorException, Exception; |
| 111 | |
| 112 | public boolean isSourceModified() |
| 113 | { |
| 114 | return resourceLoader.isSourceModified(this); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Set the modification check interval. |
| 119 | * @param interval The interval (in seconds). |
| 120 | */ |
| 121 | public void setModificationCheckInterval(long modificationCheckInterval) |
| 122 | { |
| 123 | this.modificationCheckInterval = modificationCheckInterval; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Is it time to check to see if the resource |
| 128 | * source has been updated? |
| 129 | */ |
| 130 | public boolean requiresChecking() |
| 131 | { |
| 132 | /* |
| 133 | * short circuit this if modificationCheckInterval == 0 |
| 134 | * as this means "don't check" |
| 135 | */ |
| 136 | |
| 137 | if (modificationCheckInterval <= 0 ) |
| 138 | { |
| 139 | return false; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * see if we need to check now |
| 144 | */ |
| 145 | |
| 146 | return ( System.currentTimeMillis() >= nextCheck ); |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * 'Touch' this template and thereby resetting |
| 151 | * the nextCheck field. |
| 152 | */ |
| 153 | public void touch() |
| 154 | { |
| 155 | nextCheck = System.currentTimeMillis() + ( MILLIS_PER_SECOND * modificationCheckInterval); |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * Set the name of this resource, for example |
| 160 | * test.vm. |
| 161 | */ |
| 162 | public void setName(String name) |
| 163 | { |
| 164 | this.name = name; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Get the name of this template. |
| 169 | */ |
| 170 | public String getName() |
| 171 | { |
| 172 | return name; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * set the encoding of this resource |
| 177 | * for example, "ISO-8859-1" |
| 178 | */ |
| 179 | public void setEncoding( String encoding ) |
| 180 | { |
| 181 | this.encoding = encoding; |
| 182 | } |
| 183 | |
| 184 | /** |
| 185 | * get the encoding of this resource |
| 186 | * for example, "ISO-8859-1" |
| 187 | */ |
| 188 | public String getEncoding() |
| 189 | { |
| 190 | return encoding; |
| 191 | } |
| 192 | |
| 193 | |
| 194 | /** |
| 195 | * Return the lastModifed time of this |
| 196 | * template. |
| 197 | */ |
| 198 | public long getLastModified() |
| 199 | { |
| 200 | return lastModified; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Set the last modified time for this |
| 205 | * template. |
| 206 | */ |
| 207 | public void setLastModified(long lastModified) |
| 208 | { |
| 209 | this.lastModified = lastModified; |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * Return the template loader that pulled |
| 214 | * in the template stream |
| 215 | */ |
| 216 | public ResourceLoader getResourceLoader() |
| 217 | { |
| 218 | return resourceLoader; |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * Set the template loader for this template. Set |
| 223 | * when the Runtime determines where this template |
| 224 | * came from the list of possible sources. |
| 225 | */ |
| 226 | public void setResourceLoader(ResourceLoader resourceLoader) |
| 227 | { |
| 228 | this.resourceLoader = resourceLoader; |
| 229 | } |
| 230 | |
| 231 | /** |
| 232 | * Set arbitrary data object that might be used |
| 233 | * by the resource. |
| 234 | */ |
| 235 | public void setData(Object data) |
| 236 | { |
| 237 | this.data = data; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * Get arbitrary data object that might be used |
| 242 | * by the resource. |
| 243 | */ |
| 244 | public Object getData() |
| 245 | { |
| 246 | return data; |
| 247 | } |
| 248 | } |