ExceptionClassifierRetryPolicyTests.java

/*
 * Copyright 2006-2007 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
 *
 *      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.springframework.retry.policy;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNotSame;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;

import java.util.Collections;
import java.util.HashMap;

import org.junit.Test;
import org.springframework.classify.Classifier;
import org.springframework.retry.RetryContext;
import org.springframework.retry.RetryPolicy;

public class ExceptionClassifierRetryPolicyTests {

	private ExceptionClassifierRetryPolicy policy = new ExceptionClassifierRetryPolicy();

	@Test
	public void testDefaultPolicies() throws Exception {
		RetryContext context = policy.open(null);
		assertNotNull(context);
	}

	@Test
	public void testTrivialPolicies() throws Exception {
		policy.setPolicyMap(Collections.<Class<? extends Throwable>, RetryPolicy> singletonMap(Exception.class,
				new MockRetryPolicySupport()));
		RetryContext context = policy.open(null);
		assertNotNull(context);
		assertTrue(policy.canRetry(context));
	}

	@Test
	public void testNullPolicies() throws Exception {
		policy.setPolicyMap(new HashMap<Class<? extends Throwable>, RetryPolicy>());
		RetryContext context = policy.open(null);
		assertNotNull(context);
	}

	@Test
	public void testNullContext() throws Exception {
		policy.setPolicyMap(Collections.<Class<? extends Throwable>, RetryPolicy> singletonMap(Exception.class,
				new NeverRetryPolicy()));

		RetryContext context = policy.open(null);
		assertNotNull(context);

		assertTrue(policy.canRetry(context));
	}

	@SuppressWarnings("serial")
	@Test
	public void testClassifierOperates() throws Exception {

		RetryContext context = policy.open(null);
		assertNotNull(context);

		assertTrue(policy.canRetry(context));
		policy.registerThrowable(context, new IllegalArgumentException());
		assertFalse(policy.canRetry(context)); // NeverRetryPolicy is the
		// default

		policy.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
			public RetryPolicy classify(Throwable throwable) {
				if (throwable != null) {
					return new AlwaysRetryPolicy();
				}
				return new NeverRetryPolicy();
			}
		});

		// The context saves the classifier, so changing it now has no effect
		assertFalse(policy.canRetry(context));
		policy.registerThrowable(context, new IllegalArgumentException());
		assertFalse(policy.canRetry(context));

		// But now the classifier will be active in the new context...
		context = policy.open(null);
		assertTrue(policy.canRetry(context));
		policy.registerThrowable(context, new IllegalArgumentException());
		assertTrue(policy.canRetry(context));

	}

	int count = 0;

	@SuppressWarnings("serial")
	@Test
	public void testClose() throws Exception {
		policy.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
			public RetryPolicy classify(Throwable throwable) {
				return new MockRetryPolicySupport() {
					public void close(RetryContext context) {
						count++;
					}
				};
			}
		});
		RetryContext context = policy.open(null);

		// The mapped (child) policy hasn't been used yet, so if we close now
		// we don't incur the possible expense of creating the child context.
		policy.close(context);
		assertEquals(0, count); // not classified yet
		// This forces a child context to be created and the child policy is
		// then closed
		policy.registerThrowable(context, new IllegalStateException());
		policy.close(context);
		assertEquals(1, count); // now classified
	}

	@Test
	public void testRetryCount() throws Exception {
		ExceptionClassifierRetryPolicy policy = new ExceptionClassifierRetryPolicy();
		RetryContext context = policy.open(null);
		assertNotNull(context);
		policy.registerThrowable(context, null);
		assertEquals(0, context.getRetryCount());
		policy.registerThrowable(context, new RuntimeException("foo"));
		assertEquals(1, context.getRetryCount());
		assertEquals("foo", context.getLastThrowable().getMessage());
	}

	@Test
	public void testParent() throws Exception {
		ExceptionClassifierRetryPolicy policy = new ExceptionClassifierRetryPolicy();
		RetryContext context = policy.open(null);
		RetryContext child = policy.open(context);
		assertNotSame(child, context);
		assertSame(context, child.getParent());
	}

}