scriptella.core.OnErrorHandler Maven / Gradle / Ivy
/*
* Copyright 2006-2012 The Scriptella Project Team.
*
* 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 scriptella.core;
import scriptella.configuration.OnErrorEl;
import scriptella.configuration.ScriptEl;
import scriptella.spi.ProviderException;
import scriptella.util.ExceptionUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.regex.Pattern;
/**
* Error handler for scripting elements.
* This class maintains an internal copy of {@link #onerrorElements} for
* {@link ScriptEl} to allow calling {@link #onError(Throwable)} several times
* with different return result.
*
* @author Fyodor Kupolov
* @version 1.0
*/
public class OnErrorHandler {
private List onerrorElements;
//Stores error identifiers
/**
* Initialize error handler with the list of {@link OnErrorEl}.
*
* @param scriptEl scripting element configuration to get onerror info.
*/
public OnErrorHandler(ScriptEl scriptEl) {
List onerrorElements = scriptEl.getOnerrorElements();
if (onerrorElements != null && onerrorElements.size() > 0) {
this.onerrorElements = new ArrayList(onerrorElements);
}
}
/**
* Called on error to get a {@link OnErrorEl} with fallback script.
* Note: The returned OnErrorEl element is removed from internal list of elements to avoid
* handling the same error condition twice.
*
* @param throwable
* @return OnErrorEl matching error condition.
*/
public OnErrorEl onError(Throwable throwable) {
if (onerrorElements == null) {
return null;
}
//walks down the throwables chain
for (Throwable t = throwable; t != null; t = ExceptionUtils.getCause(t)) {
//iterates through elements
for (OnErrorEl onErrorEl : onerrorElements) {
Pattern type = onErrorEl.getType();
if (type != null && !type.matcher(t.getClass().getName()).find()) {
continue;
}
Pattern msg = onErrorEl.getMessage();
//if onerror has message, but exception hasn't or different message - skip this case
if (msg != null && (t.getMessage() == null || !msg.matcher(t.getMessage()).find())) {
continue;
}
Set codes = onErrorEl.getCodes();
if (codes != null && !codes.isEmpty()) {
Set errorCodes = getErrorCodes(t);
boolean match = false;
//check if onerror matches any error code for the throwable
for (String ec : errorCodes) {
if (codes.contains(ec)) {
match = true;
break;
}
}
if (!match) {
continue;
}
}
//Next time we should not visit this element
onerrorElements.remove(onErrorEl);
return onErrorEl;
}
}
return null;
}
/**
* @param t throwables chain.
* @return not null set of found error codes in throwable chain.
*/
protected Set getErrorCodes(Throwable t) {
if (t instanceof ProviderException) {
return ((ProviderException) t).getErrorCodes();
}
return Collections.emptySet();
}
}