org.apache.hadoop.io.retry.RetryProxy Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hadoop.io.retry;
import java.lang.reflect.Proxy;
import java.util.Map;
/**
*
* A factory for creating retry proxies.
*
*/
public class RetryProxy {
/**
*
* Create a proxy for an interface of an implementation class
* using the same retry policy for each method in the interface.
*
* @param iface the interface that the retry will implement
* @param implementation the instance whose methods should be retried
* @param retryPolicy the policy for retrying method call failures
* @return the retry proxy
*/
public static Object create(Class iface, T implementation,
RetryPolicy retryPolicy) {
return RetryProxy.create(iface,
new DefaultFailoverProxyProvider(iface, implementation),
retryPolicy);
}
/**
* Create a proxy for an interface of implementations of that interface using
* the given {@link FailoverProxyProvider} and the same retry policy for each
* method in the interface.
*
* @param iface the interface that the retry will implement
* @param proxyProvider provides implementation instances whose methods should be retried
* @param retryPolicy the policy for retrying or failing over method call failures
* @return the retry proxy
*/
public static Object create(Class iface,
FailoverProxyProvider proxyProvider, RetryPolicy retryPolicy) {
return Proxy.newProxyInstance(
proxyProvider.getInterface().getClassLoader(),
new Class[] { iface },
new RetryInvocationHandler(proxyProvider, retryPolicy)
);
}
/**
* Create a proxy for an interface of an implementation class
* using the a set of retry policies specified by method name.
* If no retry policy is defined for a method then a default of
* {@link RetryPolicies#TRY_ONCE_THEN_FAIL} is used.
*
* @param iface the interface that the retry will implement
* @param implementation the instance whose methods should be retried
* @param methodNameToPolicyMap a map of method names to retry policies
* @return the retry proxy
*/
public static Object create(Class iface, T implementation,
Map methodNameToPolicyMap) {
return create(iface,
new DefaultFailoverProxyProvider(iface, implementation),
methodNameToPolicyMap,
RetryPolicies.TRY_ONCE_THEN_FAIL);
}
/**
* Create a proxy for an interface of implementations of that interface using
* the given {@link FailoverProxyProvider} and the a set of retry policies
* specified by method name. If no retry policy is defined for a method then a
* default of {@link RetryPolicies#TRY_ONCE_THEN_FAIL} is used.
*
* @param iface the interface that the retry will implement
* @param proxyProvider provides implementation instances whose methods should be retried
* @param methodNameToPolicyMap map of method names to retry policies
* @return the retry proxy
*/
public static Object create(Class iface,
FailoverProxyProvider proxyProvider,
Map methodNameToPolicyMap,
RetryPolicy defaultPolicy) {
return Proxy.newProxyInstance(
proxyProvider.getInterface().getClassLoader(),
new Class[] { iface },
new RetryInvocationHandler(proxyProvider, defaultPolicy,
methodNameToPolicyMap)
);
}
}