/*
* 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.catalina.ha.deploy;
import java.io.File;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;
/**
* The <b>WarWatcher </b> watches the deployDir for changes made to the directory (adding new WAR files->deploy or
* remove WAR files->undeploy) and notifies a listener of the changes made.
*/
public class WarWatcher {
/*--Static Variables----------------------------------------*/
private static final Log log = LogFactory.getLog(WarWatcher.class);
private static final StringManager sm = StringManager.getManager(WarWatcher.class);
/*--Instance Variables--------------------------------------*/
/**
* Directory to watch for war files
*/
protected final File watchDir;
/**
* Parent to be notified of changes
*/
protected final FileChangeListener listener;
/**
* Currently deployed files
*/
protected final Map<String,WarInfo> currentStatus = new HashMap<>();
/*--Constructor---------------------------------------------*/
public WarWatcher(FileChangeListener listener, File watchDir) {
this.listener = listener;
this.watchDir = watchDir;
}
/*--Logic---------------------------------------------------*/
/**
* check for modification and send notification to listener
*/
public void check() {
if (log.isDebugEnabled()) {
log.debug(sm.getString("warWatcher.checkingWars", watchDir));
}
File[] list = watchDir.listFiles(new WarFilter());
if (list == null) {
log.warn(sm.getString("warWatcher.cantListWatchDir", watchDir));
list = new File[0];
}
// first make sure all the files are listed in our current status
for (File file : list) {
if (!file.exists()) {
log.warn(sm.getString("warWatcher.listedFileDoesNotExist", file, watchDir));
}
addWarInfo(file);
}
// Check all the status codes and update the FarmDeployer
for (Iterator<Map.Entry<String,WarInfo>> i = currentStatus.entrySet().iterator(); i.hasNext();) {
Map.Entry<String,WarInfo> entry = i.next();
WarInfo info = entry.getValue();
if (log.isTraceEnabled()) {
log.trace(sm.getString("warWatcher.checkingWar", info.getWar()));
}
int check = info.check();
if (check == 1) {
listener.fileModified(info.getWar());
} else if (check == -1) {
listener.fileRemoved(info.getWar());
// no need to keep in memory
i.remove();
}
if (log.isTraceEnabled()) {
log.trace(sm.getString("warWatcher.checkWarResult", Integer.valueOf(check), info.getWar()));
}
}
}
/**
* add cluster war to the watcher state
*
* @param warfile The WAR to add
*/
protected void addWarInfo(File warfile) {
WarInfo info = currentStatus.get(warfile.getAbsolutePath());
if (info == null) {
info = new WarInfo(warfile);
info.setLastState(-1); // assume file is non existent
currentStatus.put(warfile.getAbsolutePath(), info);
}
}
/**
* clear watcher state
*/
public void clear() {
currentStatus.clear();
}
/*--Inner classes-------------------------------------------*/
/**
* File name filter for war files
*/
protected static class WarFilter implements java.io.FilenameFilter {
@Override
public boolean accept(File path, String name) {
if (name == null) {
return false;
}
return name.endsWith(".war");
}
}
/**
* File information on existing WAR files
*/
protected static class WarInfo {
protected final File war;
protected long lastChecked;
protected long lastState = 0;
public WarInfo(File war) {
this.war = war;
this.lastChecked = war.lastModified();
if (!war.exists()) {
lastState = -1;
}
}
public boolean modified() {
return war.exists() && war.lastModified() > lastChecked;
}
public boolean exists() {
return war.exists();
}
/**
* Returns 1 if the file has been added/modified, 0 if the file is unchanged and -1 if the file has been removed
*
* @return int 1=file added; 0=unchanged; -1=file removed
*/
public int check() {
// file unchanged by default
int result = 0;
if (modified()) {
// file has changed - timestamp
result = 1;
lastState = result;
} else if ((!exists()) && (!(lastState == -1))) {
// file was removed
result = -1;
lastState = result;
} else if ((lastState == -1) && exists()) {
// file was added
result = 1;
lastState = result;
}
this.lastChecked = System.currentTimeMillis();
return result;
}
public File getWar() {
return war;
}
@Override
public int hashCode() {
return war.getAbsolutePath().hashCode();
}
@Override
public boolean equals(Object other) {
if (other instanceof WarInfo wo) {
return wo.getWar().equals(getWar());
} else {
return false;
}
}
protected void setLastState(int lastState) {
this.lastState = lastState;
}
}
}