| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * 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. |
| * |
| */ |
| |
| package org.apache.tools.ant.types.selectors.modifiedselector; |
| |
| |
| import java.util.Iterator; |
| import java.util.Vector; |
| import java.util.Enumeration; |
| import java.util.Properties; |
| import java.io.File; |
| import java.io.BufferedInputStream; |
| import java.io.FileInputStream; |
| import java.io.BufferedOutputStream; |
| import java.io.FileOutputStream; |
| |
| |
| /** |
| * Use java.util.Properties for storing the values. |
| * The use of this Cache-implementation requires the use of the parameter |
| * <param name="cache.cachefile" .../> for defining, where to store the |
| * properties file. |
| * |
| * The ModifiedSelector sets the <i>cachefile</i> to the default value |
| * <i>cache.properties</i>. |
| * |
| * Supported <param>s are: |
| * <table> |
| * <tr> |
| * <th>name</th><th>values</th><th>description</th><th>required</th> |
| * </tr> |
| * <tr> |
| * <td> cache.cachefile </td> |
| * <td> <i>path to file</i> </td> |
| * <td> the name of the properties file </td> |
| * <td> yes </td> |
| * </tr> |
| * </table> |
| * |
| * @version 2003-09-13 |
| * @since Ant 1.6 |
| */ |
| public class PropertiesfileCache implements Cache { |
| |
| |
| // ----- member variables - configuration ----- |
| |
| |
| /** Where to store the properties? */ |
| private File cachefile = null; |
| |
| /** Object for storing the key-value-pairs. */ |
| private Properties cache = new Properties(); |
| |
| |
| // ----- member variables - internal use ----- |
| |
| |
| /** Is the cache already loaded? Prevents from multiple load operations. */ |
| private boolean cacheLoaded = false; |
| |
| /** Must the cache be saved? Prevents from multiple save operations. */ |
| private boolean cacheDirty = true; |
| |
| |
| // ----- Constructors ----- |
| |
| |
| /** Bean-Constructor. */ |
| public PropertiesfileCache() { |
| } |
| |
| /** |
| * Constructor. |
| * @param cachefile set the cachefile |
| */ |
| public PropertiesfileCache(File cachefile) { |
| this.cachefile = cachefile; |
| } |
| |
| |
| // ----- Cache-Configuration ----- |
| |
| |
| /** |
| * Setter. |
| * @param file new value |
| */ |
| public void setCachefile(File file) { |
| cachefile = file; |
| } |
| |
| |
| /** |
| * Getter. |
| * @return the cachefile |
| */ |
| public File getCachefile() { |
| return cachefile; |
| } |
| |
| /** |
| * This cache is valid if the cachefile is set. |
| * @return true if all is ok false otherwise |
| */ |
| public boolean isValid() { |
| return (cachefile != null); |
| } |
| |
| |
| // ----- Data Access |
| |
| |
| /** |
| * Load the cache from underlying properties file. |
| */ |
| public void load() { |
| if ((cachefile != null) && cachefile.isFile() && cachefile.canRead()) { |
| try { |
| BufferedInputStream bis = new BufferedInputStream( |
| new FileInputStream(cachefile)); |
| cache.load(bis); |
| bis.close(); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } |
| } |
| // after loading the cache is up to date with the file |
| cacheLoaded = true; |
| cacheDirty = false; |
| } |
| |
| /** |
| * Saves modification of the cache. |
| * Cache is only saved if there is one ore more entries. |
| * Because entries can not be deleted by this API, this Cache |
| * implementation checks the existence of entries before creating the file |
| * for performance optimisation. |
| */ |
| public void save() { |
| if (!cacheDirty) { |
| return; |
| } |
| if ((cachefile != null) && cache.propertyNames().hasMoreElements()) { |
| try { |
| BufferedOutputStream bos = new BufferedOutputStream( |
| new FileOutputStream(cachefile)); |
| cache.store(bos, null); |
| bos.flush(); |
| bos.close(); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } |
| } |
| cacheDirty = false; |
| } |
| |
| /** Deletes the cache and its underlying file. */ |
| public void delete() { |
| cache = new Properties(); |
| cachefile.delete(); |
| cacheLoaded = true; |
| cacheDirty = false; |
| } |
| |
| /** |
| * Returns a value for a given key from the cache. |
| * @param key the key |
| * @return the stored value |
| */ |
| public Object get(Object key) { |
| if (!cacheLoaded) { |
| load(); |
| } |
| try { |
| return cache.getProperty(String.valueOf(key)); |
| } catch (ClassCastException e) { |
| return null; |
| } |
| } |
| |
| /** |
| * Saves a key-value-pair in the cache. |
| * @param key the key |
| * @param value the value |
| */ |
| public void put(Object key, Object value) { |
| cache.put(String.valueOf(key), String.valueOf(value)); |
| cacheDirty = true; |
| } |
| |
| /** |
| * Returns an iterator over the keys in the cache. |
| * @return An iterator over the keys. |
| */ |
| public Iterator iterator() { |
| Vector v = new java.util.Vector(); |
| Enumeration en = cache.propertyNames(); |
| while (en.hasMoreElements()) { |
| v.add(en.nextElement()); |
| } |
| return v.iterator(); |
| } |
| |
| |
| // ----- additional ----- |
| |
| |
| /** |
| * Override Object.toString(). |
| * @return information about this cache |
| */ |
| public String toString() { |
| StringBuffer buf = new StringBuffer(); |
| buf.append("<PropertiesfileCache:"); |
| buf.append("cachefile=").append(cachefile); |
| buf.append(";noOfEntries=").append(cache.size()); |
| buf.append(">"); |
| return buf.toString(); |
| } |
| } |