Files
java-design-patterns/circuit-breaker/src/main/java/com/iluwatar/circuitbreaker/DelayedRemoteService.java
2020-10-01 21:09:39 +05:30

69 lines
2.6 KiB
Java

/*
* The MIT License
* Copyright © 2014-2019 Ilkka Seppälä
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package com.iluwatar.circuitbreaker;
/**
* This simulates the remote service It responds only after a certain timeout period (default set to
* 20 seconds).
*/
public class DelayedRemoteService implements RemoteService {
private final long serverStartTime;
private final int delay;
/**
* Constructor to create an instance of DelayedService, which is down for first few seconds.
*
* @param delay the delay after which service would behave properly, in seconds
*/
public DelayedRemoteService(long serverStartTime, int delay) {
this.serverStartTime = serverStartTime;
this.delay = delay;
}
public DelayedRemoteService() {
this.serverStartTime = System.nanoTime();
this.delay = 20;
}
/**
* Responds based on delay, current time and server start time if the service is down / working.
*
* @return The state of the service
*/
@Override
public String call() throws RemoteServiceException {
var currentTime = System.nanoTime();
//Since currentTime and serverStartTime are both in nanoseconds, we convert it to
//seconds by diving by 10e9 and ensure floating point division by multiplying it
//with 1.0 first. We then check if it is greater or less than specified delay and then
//send the reply
if ((currentTime - serverStartTime) * 1.0 / (1000 * 1000 * 1000) < delay) {
//Can use Thread.sleep() here to block and simulate a hung server
throw new RemoteServiceException("Delayed service is down");
}
return "Delayed service is working";
}
}