org.springframework.cloud.netflix.ribbon.support.RetryableLoadBalancingClient.java Source code

Introduction

Here is the source code for org.springframework.cloud.netflix.ribbon.support.RetryableLoadBalancingClient.java

Source

/*
 *
 * Copyright 2013-2016 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.cloud.netflix.ribbon.support;

import java.io.IOException;
import org.apache.commons.lang.BooleanUtils;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.InterceptorRetryPolicy;
import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryPolicy;
import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryPolicyFactory;
import org.springframework.cloud.client.loadbalancer.ServiceInstanceChooser;
import org.springframework.cloud.netflix.feign.ribbon.FeignRetryPolicy;
import org.springframework.cloud.netflix.ribbon.RibbonLoadBalancerClient;
import org.springframework.cloud.netflix.ribbon.ServerIntrospector;
import org.springframework.http.HttpRequest;
import org.springframework.retry.RetryCallback;
import org.springframework.retry.policy.NeverRetryPolicy;
import org.springframework.retry.support.RetryTemplate;
import com.netflix.client.IResponse;
import com.netflix.client.RequestSpecificRetryHandler;
import com.netflix.client.RetryHandler;
import com.netflix.client.config.IClientConfig;
import com.netflix.loadbalancer.ILoadBalancer;
import com.netflix.loadbalancer.Server;

/**
 * A load balancing client which uses Spring Retry to retry failed requests.
 * @author Ryan Baxter
 */
public abstract class RetryableLoadBalancingClient<S extends ContextAwareRequest, T extends IResponse, D>
        extends AbstractLoadBalancingClient<S, T, D> implements ServiceInstanceChooser {

    protected LoadBalancedRetryPolicyFactory loadBalancedRetryPolicyFactory = new LoadBalancedRetryPolicyFactory.NeverRetryFactory();

    @Deprecated
    public RetryableLoadBalancingClient() {
        super();
    }

    @Deprecated
    public RetryableLoadBalancingClient(final ILoadBalancer lb) {
        super(lb);
    }

    public RetryableLoadBalancingClient(IClientConfig config, ServerIntrospector serverIntrospector) {
        super(config, serverIntrospector);
    }

    public RetryableLoadBalancingClient(D delegate, IClientConfig config, ServerIntrospector serverIntrospector) {
        super(delegate, config, serverIntrospector);
    }

    public RetryableLoadBalancingClient(IClientConfig iClientConfig, ServerIntrospector serverIntrospector,
            LoadBalancedRetryPolicyFactory loadBalancedRetryPolicyFactory) {
        this(iClientConfig, serverIntrospector);
        this.loadBalancedRetryPolicyFactory = loadBalancedRetryPolicyFactory;
    }

    /**
     * Executes a {@link S} using Spring Retry.
     * @param request The request to execute.
     * @param callback The retry callback to use.
     * @return The response.
     * @throws Exception Thrown if there is an error making the request and a retry cannot be completed successfully.
     */
    protected T executeWithRetry(S request, RetryCallback<T, IOException> callback) throws Exception {
        LoadBalancedRetryPolicy retryPolicy = loadBalancedRetryPolicyFactory.create(this.getClientName(), this);
        RetryTemplate retryTemplate = new RetryTemplate();
        boolean retryable = request.getContext() == null ? true
                : BooleanUtils.toBooleanDefaultIfNull(request.getContext().getRetryable(), true);
        retryTemplate.setRetryPolicy(retryPolicy == null || !retryable ? new NeverRetryPolicy()
                : new RetryPolicy(request, retryPolicy, this, this.getClientName()));
        return retryTemplate.execute(callback);
    }

    @Override
    public ServiceInstance choose(String serviceId) {
        Server server = this.getLoadBalancer().chooseServer(serviceId);
        return new RibbonLoadBalancerClient.RibbonServer(serviceId, server);
    }

    @Override
    public RequestSpecificRetryHandler getRequestSpecificRetryHandler(S request, IClientConfig requestConfig) {
        return new RequestSpecificRetryHandler(false, false, RetryHandler.DEFAULT, null);
    }

    static class RetryPolicy extends FeignRetryPolicy {
        public RetryPolicy(HttpRequest request, LoadBalancedRetryPolicy policy,
                ServiceInstanceChooser serviceInstanceChooser, String serviceName) {
            super(request, policy, serviceInstanceChooser, serviceName);
        }
    }

}