我正在尝试测试使用自定义重试策略的重试模板。为了做到这一点，我正在使用这个例子：
基本上，我的目标是在我得到一些特定的 http 错误状态（例如 http 500 错误状态）时测试我的重试逻辑。
这是我的 junit 的 xml 上下文：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:int="http://www.springframework.org/schema/integration"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int-http="http://www.springframework.org/schema/integration/http"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/integration
http://www.springframework.org/schema/integration/spring-integration.xsd
http://www.springframework.org/schema/integration/http
http://www.springframework.org/schema/integration/http/spring-integration-http.xsd">
<bean id="retryTemplate_test" class="org.springframework.retry.support.RetryTemplate">
<property name="retryPolicy">
<bean
class="util.CustomRetryPolicy">
<property name="maxAttempts" value="5" />
</bean>
</property>
<property name="backOffPolicy">
<bean class="org.springframework.retry.backoff.ExponentialBackOffPolicy">
<property name="initialInterval" value="1000" />
<property name="multiplier" value="6" />
</bean>
</property>
</bean>
</beans>
CustomRetryPolicy就像：
public class CustomRetryPolicy extends ExceptionClassifierRetryPolicy {
private String maxAttempts;
@PostConstruct
public void init() {
this.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
@Override
public RetryPolicy classify(Throwable classifiable) {
Throwable exceptionCause = classifiable.getCause();
if (exceptionCause instanceof HttpStatusCodeException) {
int statusCode = ((HttpStatusCodeException) classifiable.getCause()).getStatusCode().value();
return handleHttpErrorCode(statusCode);
}
return neverRetry();
}
});
}
public void setMaxAttempts(String maxAttempts) {
this.maxAttempts = maxAttempts;
}
private RetryPolicy handleHttpErrorCode(int statusCode) {
RetryPolicy retryPolicy = null;
switch(statusCode) {
case 404 :
case 500 :
case 503 :
case 504 :
retryPolicy = defaultRetryPolicy();
break;
default :
retryPolicy = neverRetry();
break;
}
return retryPolicy;
}
private RetryPolicy neverRetry() {
return new NeverRetryPolicy();
}
private RetryPolicy defaultRetryPolicy() {
final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
simpleRetryPolicy.setMaxAttempts(Integer.valueOf(maxAttempts));
return simpleRetryPolicy;
}
}
我正在测试的 Java 类是：
@RunWith( SpringJUnit4ClassRunner.class )
@ContextConfiguration(locations = {"classpath:my_context_for_test.xml"})
public class RetryTemplateTest{
@Autowired
@Qualifier("retryTemplate_test")
RetryTemplate retryTemplate_test;
@Test
public void testRetry() throws Throwable {
Map<Class<? extends Throwable>, Boolean> r = new HashMap<>();
r.put(HttpStatusCodeException.class, true);
MockRetryCallback callback = new MockRetryCallback();
callback.setAttemptsBeforeSuccess(5);
retryTemplate_test.execute(callback);
assertEquals(5, callback.attempts);
}
private static class MockRetryCallback implements RetryCallback<Object, HttpStatusCodeException> {
private int attempts;
private int attemptsBeforeSuccess;
@SuppressWarnings("serial")
@Override
public Object doWithRetry(RetryContext status) throws HttpStatusCodeException {
this.attempts++;
if (this.attempts < this.attemptsBeforeSuccess) {
System.out.println("I'm here: "+ this.attempts);
throw new HttpStatusCodeException(HttpStatus.INTERNAL_SERVER_ERROR) {
};
}
return null;
}
public void setAttemptsBeforeSuccess(int attemptsBeforeSuccess) {
this.attemptsBeforeSuccess = attemptsBeforeSuccess;
}
}
}
我究竟做错了什么？我的理解是，使用回调，我正在模拟一个响应，并且我可以处理（使用我的自定义重试策略）该响应。还
[更新]
如果我尝试复制这个 junit，那么我会遇到同样的异常。最具体地说，当尝试在此处MockRetryCallback的类中实例化异常时，它会失败：
private Exception exceptionToThrow = new Exception();