/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2011, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.core.boolex;
import java.util.ArrayList;
import java.util.List;
import org.codehaus.janino.ExpressionEvaluator;
import org.codehaus.janino.ScriptEvaluator;
/**
* Abstract class which sets the groundwork for janino based evaluations.
*
* @author Ceki Gülcü
*
* @param <E>
*/
abstract public class JaninoEventEvaluatorBase<E> extends EventEvaluatorBase<E> {
static Class EXPRESSION_TYPE = boolean.class;
static Class[] THROWN_EXCEPTIONS = new Class[1];
static public final int ERROR_THRESHOLD = 4;
static {
THROWN_EXCEPTIONS[0] = EvaluationException.class;
}
private String expression;
ScriptEvaluator scriptEvaluator;
private int errorCount = 0;
abstract protected String getDecoratedExpression();
abstract protected String[] getParameterNames();
abstract protected Class[] getParameterTypes();
abstract protected Object[] getParameterValues(E event);
protected List<Matcher> matcherList = new ArrayList<Matcher>();
@Override
public void start() {
try {
assert context != null;
scriptEvaluator = new ScriptEvaluator(getDecoratedExpression(), EXPRESSION_TYPE,
getParameterNames(), getParameterTypes(), THROWN_EXCEPTIONS);
super.start();
} catch (Exception e) {
addError(
"Could not start evaluator with expression [" + expression + "]", e);
}
}
public boolean evaluate(E event) throws EvaluationException {
if (!isStarted()) {
throw new IllegalStateException("Evaluator [" + name
+ "] was called in stopped state");
}
try {
Boolean result = (Boolean) scriptEvaluator.evaluate(getParameterValues(event));
return result.booleanValue();
} catch (Exception ex) {
errorCount++;
if (errorCount >= ERROR_THRESHOLD) {
stop();
}
throw new EvaluationException("Evaluator [" + name
+ "] caused an exception", ex);
}
}
public String getExpression() {
return expression;
}
public void setExpression(String expression) {
this.expression = expression;
}
public void addMatcher(Matcher matcher) {
matcherList.add(matcher);
}
public List getMatcherList() {
return matcherList;
}
}