com.sun.syndication.fetcher.impl.DiskFeedInfoCache Maven / Gradle / Ivy
/*
* Copyright 2005 Sun Microsystems, Inc.
*
* Licensed 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 com.sun.syndication.fetcher.impl;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.URL;
import javax.swing.text.Utilities;
/**
* Disk based cache.
*/
public class DiskFeedInfoCache implements FeedFetcherCache {
protected String cachePath = null;
public DiskFeedInfoCache(String cachePath) {
this.cachePath = cachePath;
}
public SyndFeedInfo getFeedInfo(URL url) {
SyndFeedInfo info = null;
String fileName = cachePath + File.separator + "feed_"
+ replaceNonAlphanumeric(url.toString(),'_').trim();
FileInputStream fis;
try {
fis = new FileInputStream(fileName);
ObjectInputStream ois = new ObjectInputStream(fis);
info = (SyndFeedInfo)ois.readObject();
fis.close();
} catch (FileNotFoundException fnfe) {
// That's OK, we'l return null
} catch (ClassNotFoundException cnfe) {
// Error writing to cache is fatal
throw new RuntimeException("Attempting to read from cache", cnfe);
} catch (IOException fnfe) {
// Error writing to cache is fatal
throw new RuntimeException("Attempting to read from cache", fnfe);
}
return info;
}
public void setFeedInfo(URL url, SyndFeedInfo feedInfo) {
String fileName = cachePath + File.separator + "feed_"
+ replaceNonAlphanumeric(url.toString(),'_').trim();
FileOutputStream fos;
try {
fos = new FileOutputStream(fileName);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(feedInfo);
fos.flush();
fos.close();
} catch (Exception e) {
// Error writing to cache is fatal
throw new RuntimeException("Attempting to write to cache", e);
}
}
public static String replaceNonAlphanumeric(String str, char subst) {
StringBuffer ret = new StringBuffer(str.length());
char[] testChars = str.toCharArray();
for (int i = 0; i < testChars.length; i++) {
if (Character.isLetterOrDigit(testChars[i])) {
ret.append(testChars[i]);
} else {
ret.append( subst );
}
}
return ret.toString();
}
/**
* Clear the cache.
*/
public synchronized void clear() {
final File file = new File(this.cachePath);
//only do the delete if the directory exists
if( file.exists() && file.canWrite() ) {
//make the directory empty
final String[] files = file.list();
final int len = files.length;
for( int i=0; i