org.snmp4j.agent.cfg.EngineBootsCounterFile Maven / Gradle / Ivy
/*_############################################################################
_##
_## SNMP4J-Agent - EngineBootsCounterFile.java
_##
_## Copyright (C) 2005-2009 Frank Fock (SNMP4J.org)
_##
_## 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 org.snmp4j.agent.cfg;
import java.io.File;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import org.snmp4j.log.LogAdapter;
import org.snmp4j.log.LogFactory;
/**
* The EngineBootsCounterFile is a {@link EngineBootsProvider}
* that stores the boot counter in a file.
*
* @author Frank Fock
* @version 1.2
*/
public class EngineBootsCounterFile implements EngineBootsProvider {
private static final LogAdapter logger =
LogFactory.getLogger(EngineBootsCounterFile.class);
private File bootCounterFile;
private int boots = -1;
/**
* Creates the boot counter by using the specified file.
* @param bootCounterFile
* a file (does not have to exists yet but must be writable).
*/
public EngineBootsCounterFile(File bootCounterFile) {
this.bootCounterFile = bootCounterFile;
}
/**
* Returns the current engine boot counter value incremented by one.
*
* @return the last engine boots counter incremented by one.
*/
public int updateEngineBoots() {
boots = getLastEngineBoots();
boots++;
if (boots <= 0) {
boots = 1;
}
setEngineBoots(boots);
return boots;
}
/**
* Reads the engine boots counter from the corresponding input stream (file).
* @return
* the boots counter value read or zero if it could not be read.
*/
protected int getLastEngineBoots() {
FileInputStream fis = null;
try {
fis = new FileInputStream(bootCounterFile);
ObjectInputStream ois = new ObjectInputStream(fis);
int boots = ois.readInt();
if (logger.isInfoEnabled()) {
logger.info("Engine boots is: "+boots);
}
return boots;
}
catch (FileNotFoundException ex) {
logger.warn("Could not find boot counter file: "+bootCounterFile);
}
catch (IOException iox) {
if (logger.isDebugEnabled()) {
iox.printStackTrace();
}
logger.error("Failed to read boot counter: "+iox.getMessage());
}
finally {
if (fis != null) {
try {
fis.close();
}
catch (IOException ex1) {
logger.warn(ex1);
}
}
}
return 0;
}
protected void setEngineBoots(int engineBoots) {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(bootCounterFile);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeInt(engineBoots);
oos.close();
if (logger.isInfoEnabled()) {
logger.info("Wrote boot counter: " + engineBoots);
}
}
catch (FileNotFoundException fnfex) {
logger.error("Boot counter configuration file not found: "+
fnfex.getMessage());
}
catch (IOException iox) {
logger.error("Failed to write boot counter: "+iox.getMessage());
}
finally {
if (fos != null) {
try {
fos.close();
}
catch (IOException ex1) {
logger.warn(ex1);
}
}
}
}
public int getEngineBoots() {
if (boots < 0) {
boots = getLastEngineBoots();
}
return boots;
}
}