org.springframework.util.backoff.FixedBackOff Maven / Gradle / Ivy
/*
* Copyright 2002-2016 the original author or authors.
*
* 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
*
* https://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.springframework.util.backoff;
/**
* A simple {@link BackOff} implementation that provides a fixed interval
* between two attempts and a maximum number of retries.
*
* @author Stephane Nicoll
* @since 4.1
*/
public class FixedBackOff implements BackOff {
/**
* The default recovery interval: 5000 ms = 5 seconds.
*/
public static final long DEFAULT_INTERVAL = 5000;
/**
* Constant value indicating an unlimited number of attempts.
*/
public static final long UNLIMITED_ATTEMPTS = Long.MAX_VALUE;
private long interval = DEFAULT_INTERVAL;
private long maxAttempts = UNLIMITED_ATTEMPTS;
/**
* Create an instance with an interval of {@value #DEFAULT_INTERVAL}
* ms and an unlimited number of attempts.
*/
public FixedBackOff() {
}
/**
* Create an instance.
* @param interval the interval between two attempts
* @param maxAttempts the maximum number of attempts
*/
public FixedBackOff(long interval, long maxAttempts) {
this.interval = interval;
this.maxAttempts = maxAttempts;
}
/**
* Set the interval between two attempts in milliseconds.
*/
public void setInterval(long interval) {
this.interval = interval;
}
/**
* Return the interval between two attempts in milliseconds.
*/
public long getInterval() {
return interval;
}
/**
* Set the maximum number of attempts in milliseconds.
*/
public void setMaxAttempts(long maxAttempts) {
this.maxAttempts = maxAttempts;
}
/**
* Return the maximum number of attempts in milliseconds.
*/
public long getMaxAttempts() {
return maxAttempts;
}
@Override
public BackOffExecution start() {
return new FixedBackOffExecution();
}
private class FixedBackOffExecution implements BackOffExecution {
private long currentAttempts = 0;
@Override
public long nextBackOff() {
this.currentAttempts++;
if (this.currentAttempts <= getMaxAttempts()) {
return getInterval();
}
else {
return STOP;
}
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder("FixedBackOff{");
sb.append("interval=").append(FixedBackOff.this.interval);
String attemptValue = (FixedBackOff.this.maxAttempts == Long.MAX_VALUE ?
"unlimited" : String.valueOf(FixedBackOff.this.maxAttempts));
sb.append(", currentAttempts=").append(this.currentAttempts);
sb.append(", maxAttempts=").append(attemptValue);
sb.append('}');
return sb.toString();
}
}
}