| /* |
| * Copyright 2009-2010 Rickard Öberg AB |
| * |
| * 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 org.qi4j.library.circuitbreaker; |
| |
| import java.beans.PropertyChangeEvent; |
| import java.beans.PropertyChangeListener; |
| import java.beans.PropertyVetoException; |
| import java.beans.VetoableChangeListener; |
| import java.io.IOException; |
| import java.util.concurrent.Callable; |
| import org.hamcrest.CoreMatchers; |
| import org.junit.Before; |
| import org.junit.Test; |
| |
| import static com.jayway.awaitility.Awaitility.await; |
| import static com.jayway.awaitility.Duration.ONE_SECOND; |
| import static org.hamcrest.core.Is.is; |
| import static org.junit.Assert.assertThat; |
| |
| /** |
| * JAVADOC |
| */ |
| public class CircuitBreakerTest |
| { |
| |
| private CircuitBreaker cb; |
| |
| @Before |
| public void createCircuitBreaker() |
| { |
| // START SNIPPET: direct |
| // Create a CircuitBreaker with a threshold of 3, a 250ms timeout, allowing IllegalArgumentExceptions |
| CircuitBreaker cb = new CircuitBreaker( 3, 250, CircuitBreakers.in( IllegalArgumentException.class ) ); |
| |
| // END SNIPPET: direct |
| |
| cb.addPropertyChangeListener( new PropertyChangeListener() |
| { |
| |
| public void propertyChange( PropertyChangeEvent evt ) |
| { |
| System.out.println( evt.getSource() + ":" + evt.getPropertyName() + "=" + evt.getOldValue() + " -> " + evt.getNewValue() ); |
| } |
| |
| } ); |
| |
| this.cb = cb; |
| } |
| |
| @Test |
| public void GivenCBWhenTripWithExceptionsAndTurnOnThenStatusIsOn() |
| throws PropertyVetoException |
| { |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // START SNIPPET: direct |
| // Service levels goes down but does not cause a trip |
| cb.throwable( new IOException() ); |
| |
| // END SNIPPET: direct |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // START SNIPPET: direct |
| // Service level goes down and causes a trip |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| |
| // END SNIPPET: direct |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.off ) ); |
| |
| // START SNIPPET: direct |
| // Turn on the CB again |
| cb.turnOn(); |
| |
| // END SNIPPET: direct |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| } |
| |
| @Test |
| public void GivenCBWhenAllowedExceptionsThenServiceLevelIsNormal() |
| throws PropertyVetoException |
| { |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // Service level goes down |
| cb.throwable( new IOException() ); |
| |
| // Service levels goes up |
| cb.throwable( new IllegalArgumentException() ); |
| |
| assertThat( cb.serviceLevel(), CoreMatchers.equalTo( 1.0 ) ); |
| } |
| |
| @Test |
| public void GivenCBWhenTripCBWithExceptionsAndTimeoutThenStatusIsOn() |
| throws PropertyVetoException |
| { |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // START SNIPPET: direct |
| // Service levels goes down and causes a trip |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| |
| // END SNIPPET: direct |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.off ) ); |
| |
| // START SNIPPET: direct |
| // Wait until timeout |
| |
| // END SNIPPET: direct |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.off ) ); |
| System.out.println( "Wait..." ); |
| await().atMost( ONE_SECOND ).until( circuitBreakerStatus(), is( CircuitBreaker.Status.on ) ); |
| |
| // START SNIPPET: direct |
| // CircuitBreaker is back on |
| |
| // END SNIPPET: direct |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| } |
| |
| private Callable<CircuitBreaker.Status> circuitBreakerStatus() |
| { |
| return new Callable<CircuitBreaker.Status>() |
| { |
| @Override |
| public CircuitBreaker.Status call() throws Exception |
| { |
| return cb.status(); |
| } |
| }; |
| } |
| |
| @Test |
| public void GivenCBWhenExceptionsAndSuccessesThenStatusIsOn() |
| throws PropertyVetoException |
| { |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // Service levels goes down and causes a trip |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| cb.success(); |
| cb.success(); |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| } |
| |
| @Test |
| public void GivenCBWhenTripCBWithExceptionsAndSuccessesThenStatusIsOff() |
| throws PropertyVetoException |
| { |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| // Service levels goes down and causes a trip |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| cb.success(); |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.off ) ); |
| } |
| |
| @Test |
| public void GivenCBWhenTripCBWithExceptionsAndGetStatusWithFailureThenStatusIsOff() |
| throws PropertyVetoException |
| { |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.on ) ); |
| |
| cb.addVetoableChangeListener( new VetoableChangeListener() |
| { |
| |
| public void vetoableChange( PropertyChangeEvent evt ) |
| throws PropertyVetoException |
| { |
| if ( evt.getNewValue() == CircuitBreaker.Status.on ) { |
| throw new PropertyVetoException( "Service is down", evt ); |
| } |
| } |
| |
| } ); |
| |
| // Service levels goes down and causes a trip |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| cb.throwable( new IOException() ); |
| |
| try { |
| System.out.println( "Wait..." ); |
| Thread.sleep( 300 ); |
| } catch ( InterruptedException e ) { |
| // Ignore |
| } |
| |
| assertThat( cb.status(), CoreMatchers.equalTo( CircuitBreaker.Status.off ) ); |
| assertThat( cb.lastThrowable().getMessage(), CoreMatchers.equalTo( "Service is down" ) ); |
| } |
| |
| } |