/*
* 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.sling.commons.testing.junit;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** JUnit Rule that implements retries, see tests for usage example */
public class RetryRule implements TestRule {
public static final int DEFAULT_DEFAULT_TIMEOUT_MSEC = 5000;
public static final int DEFAULT_DEFAULT_INTERVAL_MSEC = 500;
private static final Logger log = LoggerFactory.getLogger(RetryRule.class);
private final long defaultTimeout;
private final long defaultInterval;
/** Create a RetryRule with default values for default timeout and interval */
public RetryRule() {
this(DEFAULT_DEFAULT_TIMEOUT_MSEC, DEFAULT_DEFAULT_INTERVAL_MSEC);
}
/** Create a RetryRule with specific values for default timeout and interval */
public RetryRule(long defaultTimeout, long defaultInterval) {
this.defaultTimeout = defaultTimeout;
this.defaultInterval = defaultInterval;
}
@Override
public String toString() {
return new StringBuilder()
.append(getClass().getSimpleName())
.append(", default interval=")
.append(defaultInterval)
.append(" msec, default timeout=")
.append(defaultTimeout)
.append(" msec")
.toString();
}
public Statement apply(final Statement statement, final Description description) {
return new Statement() {
private Throwable eval(Statement stmt) {
try {
stmt.evaluate();
} catch(Throwable t) {
return t;
}
return null;
}
@Override
public void evaluate() throws Throwable {
int retries = 0;
Throwable t = eval(statement);
if(t != null) {
final Retry r = description.getAnnotation(Retry.class);
if(r != null) {
final long timeout = System.currentTimeMillis() + getTimeout(r.timeoutMsec());
while(System.currentTimeMillis() < timeout) {
retries++;
t = eval(statement);
if(t == null) {
break;
}
Thread.sleep(getInterval(r.intervalMsec()));
}
}
}
if(t != null) {
if(retries > 0) {
log.debug("{} fails after retrying {} time(s)", statement, retries);
}
throw t;
}
if(retries > 0) {
log.debug("{} succeeds after retrying {} time(s)", statement, retries);
}
}
};
}
long getTimeout(long ruleTimeout) {
return ruleTimeout > 0 ? ruleTimeout : defaultTimeout;
}
long getInterval(long ruleInterval) {
return ruleInterval > 0 ? ruleInterval : defaultInterval;
}
}