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A library that implements the NRPE protocol for JAVA applications
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/*******************************************************************************
* Copyright (c) 2007, 2014 Massimiliano Ziccardi
*
* 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 it.jnrpe.utils.thresholds;
import it.jnrpe.plugins.Metric;
import it.jnrpe.utils.BadThresholdException;
import java.io.IOException;
import java.io.PushbackReader;
import java.io.StringReader;
import java.math.BigDecimal;
/**
* Utility class for evaluating thresholds. This class represent a Threshold
* specified using the old Nagios syntax.
*
* @author Massimiliano Ziccardi
* @version $Revision: 1.0 $
*/
public class LegacyRange {
/**
* The prefix to be used to interpret the boundary of this range.
*/
private Prefixes prefix = Prefixes.RAW;
/**
* When the current state is 'MINVAL', that means that the value we are
* parsing is the definition of the minimum value.
*/
private static final int MINVAL = 0;
/**
* When the current state is 'MAXVAL', that means that the value we are is
* the definition of the maximum value.
*/
private static final int MAXVAL = 1;
/**
* When the current state is 'END', that means that we have finished parsing
* the threshold definition.
*/
private static final int END = 99;
/**
* The mimimum value as parsed from the threshold definition.
*/
private BigDecimal minVal = null;
/**
* The maximum value as parsed from the threshold definition.
*/
private BigDecimal maxVal = null;
/**
* true if the threshold is negated.
*/
private boolean negateThreshold = false;
/**
* The current state of the threshold parser.
*/
private int curState = MINVAL;
/**
* The unparsed threshold string.
*/
private final String thresholdString;
/**
* Builds the object with the specified range.
* Sets the default prefix as {@link Prefixes#RAW}
*
* @param threshold
* The range
*
* @throws BadThresholdException
* -
*/
public LegacyRange(final String threshold) throws BadThresholdException {
thresholdString = threshold;
parseRange();
}
/**
* Builds the object with the specified range and sets the prefix as
* specified by prefix
*
* @param threshold
* The range
* @param prefix
* The prefix to be used to interpret the range boundary
* values
*
* @throws BadThresholdException
* -
*/
public LegacyRange(final String threshold, final Prefixes prefix) throws BadThresholdException {
thresholdString = threshold;
this.prefix = prefix;
parseRange();
}
/**
* Parses the range definition to evaluate the minimum and maximum
* thresholds.
*
* @throws BadThresholdException
* -
*/
private void parseRange() throws BadThresholdException {
PushbackReader reader = new PushbackReader(new StringReader(thresholdString));
StringBuilder currentParsedBuffer = new StringBuilder();
byte b = 0;
try {
while ((b = (byte) reader.read()) != -1) {
currentParsedBuffer.append((char) b);
if (b == '@') {
if (curState != MINVAL) {
throw new BadThresholdException("Unparsable threshold '" + thresholdString + "'. Error at char "
+ currentParsedBuffer.length() + ": the '@' should not be there.");
}
negateThreshold = true;
continue;
}
if (b == ':') {
switch (curState) {
case MINVAL:
if (minVal == null) {
minVal = new BigDecimal(0);
}
curState = MAXVAL;
currentParsedBuffer = new StringBuilder();
continue;
case MAXVAL:
throw new BadThresholdException("Unparsable threshold '" + thresholdString + "'. Error at char "
+ currentParsedBuffer.length() + ": the ':' should not be there.");
// m_iCurState = END;
// continue;
default:
curState = MAXVAL;
}
}
if (b == '~') {
switch (curState) {
case MINVAL:
minVal = new BigDecimal(Integer.MIN_VALUE);
currentParsedBuffer = new StringBuilder();
// m_iCurState = MAXVAL;
continue;
case MAXVAL:
maxVal = new BigDecimal(Integer.MAX_VALUE);
curState = END;
currentParsedBuffer = new StringBuilder();
continue;
default:
}
}
StringBuilder numberBuffer = new StringBuilder();
// while (i < vBytes.length &&
// Character.isDigit((char)vBytes[i]))
do {
numberBuffer.append((char) b);
} while (((b = (byte) reader.read()) != -1) && (Character.isDigit((char) b) || b == '+' || b == '-' || b == '.'));
if (b != -1) {
reader.unread(b);
}
String numberString = numberBuffer.toString();
if (numberString.trim().length() == 0 || "+".equals(numberString) || "-".equals(numberString)) {
throw new BadThresholdException("A number was expected after '" + currentParsedBuffer.toString()
+ "', but an empty string was found");
}
switch (curState) {
case MINVAL:
try {
minVal = new BigDecimal(numberString.trim());
} catch (NumberFormatException nfe) {
throw new BadThresholdException("Expected a number but found '" + numberString + "' instead [" + thresholdString + "]", nfe);
}
currentParsedBuffer = new StringBuilder();
continue;
case MAXVAL:
try {
maxVal = new BigDecimal(numberString.trim());
} catch (NumberFormatException nfe) {
throw new BadThresholdException("Expected a number but found '" + numberString + "' instead", nfe);
}
currentParsedBuffer = new StringBuilder();
continue;
default:
curState = END;
currentParsedBuffer = new StringBuilder();
}
// if (i < vBytes.length)
// i-=2;
}
} catch (IOException ioe) {
// Intentionally empty...
}
if (curState == MINVAL) {
maxVal = minVal;
minVal = new BigDecimal(0);
}
if (curState == MAXVAL && maxVal == null && !thresholdString.isEmpty() && thresholdString.charAt(0) == ':') {
throw new BadThresholdException("At least one of maximum or minimum " + "value must me specified (" + thresholdString + ")");
}
}
/**
* Returns true if the value falls inside the range.
*
* @param metric
* The metric to be checked
*
* @return true if the metric value value falls inside the
* range.
* false otherwise.
*/
public final boolean isValueInside(final Metric metric) {
BigDecimal value = metric.getMetricValue(prefix);
boolean bRes = true;
// Sets the minimum value of the range
if (minVal != null) {
bRes = bRes && (value.compareTo(minVal) >= 0);
}
// Sets the maximum value of the range
if (maxVal != null) {
bRes = bRes && (value.compareTo(maxVal) <= 0);
}
if (negateThreshold) {
return !bRes;
}
return bRes;
}
/**
* @return The original unparsed threshold string.
*/
final String getThresholdString() {
return thresholdString;
}
/**
* Method toString.
* @return String
*/
@Override
public String toString() {
return "LegacyRange [minVal=" + minVal + ", maxVal=" + maxVal + ", negateThreshold=" + negateThreshold + ", curState=" + curState
+ ", thresholdString=" + thresholdString + "]";
}
}