AmazonWebserviceClientFactoryBean.java

/*
 * Copyright 2013-2014 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.aws.core.config;

import com.amazonaws.AmazonWebServiceClient;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.client.builder.AwsAsyncClientBuilder;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.client.builder.ExecutorFactory;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.RegionUtils;
import com.amazonaws.regions.Regions;
import org.springframework.beans.factory.config.AbstractFactoryBean;
import org.springframework.cloud.aws.core.region.RegionProvider;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;

import java.lang.reflect.Method;
import java.util.concurrent.ExecutorService;

/**
 * {@link org.springframework.beans.factory.FactoryBean} class to create {@link AmazonWebServiceClient} instances. This class
 * is responsible to create the respective AmazonWebServiceClient classes because the configuration through Springs's
 * BeanFactory fails due to invalid properties inside the Webservice client classes (see
 * https://github.com/aws/aws-sdk-java/issues/325)
 *
 * @author Agim Emruli
 */
public class AmazonWebserviceClientFactoryBean<T extends AmazonWebServiceClient> extends AbstractFactoryBean<T> {

    private final Class<? extends AmazonWebServiceClient> clientClass;
    private final AWSCredentialsProvider credentialsProvider;
    private RegionProvider regionProvider;
    private Region customRegion;
    private ExecutorService executor;

    public AmazonWebserviceClientFactoryBean(Class<T> clientClass,
                                             AWSCredentialsProvider credentialsProvider) {
        this.clientClass = clientClass;
        this.credentialsProvider = credentialsProvider;
    }

    public AmazonWebserviceClientFactoryBean(Class<T> clientClass, AWSCredentialsProvider credentialsProvider, RegionProvider regionProvider) {
        this(clientClass, credentialsProvider);
        setRegionProvider(regionProvider);
    }

    @Override
    public Class<?> getObjectType() {
        return this.clientClass;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected T createInstance() throws Exception {

        String builderName = this.clientClass.getName() + "Builder";
        Class<?> className = ClassUtils.resolveClassName(builderName, ClassUtils.getDefaultClassLoader());

        Method method = ClassUtils.getStaticMethod(className, "standard");
        Assert.notNull(method, "Could not find standard() method in class:'" + className.getName() + "'");

        AwsClientBuilder<?, T> builder = (AwsClientBuilder<?, T>) ReflectionUtils.invokeMethod(method, null);

        if (this.executor != null) {
            AwsAsyncClientBuilder<?, T> asyncBuilder = (AwsAsyncClientBuilder<?, T>) builder;
            asyncBuilder.withExecutorFactory(new ExecutorFactory() {

                @Override
                public ExecutorService newExecutor() {
                    return AmazonWebserviceClientFactoryBean.this.executor;
                }
            });
        }

        if (this.credentialsProvider != null) {
            builder.withCredentials(this.credentialsProvider);
        }

        if (this.customRegion != null) {
            builder.withRegion(this.customRegion.getName());
        } else if (this.regionProvider != null) {
            builder.withRegion(this.regionProvider.getRegion().getName());
        } else {
            builder.withRegion(Regions.DEFAULT_REGION);
        }
        return builder.build();
    }

    public void setRegionProvider(RegionProvider regionProvider) {
        this.regionProvider = regionProvider;
    }

    public void setCustomRegion(String customRegionName) {
        this.customRegion = RegionUtils.getRegion(customRegionName);
    }

    public void setExecutor(ExecutorService executor) {
        this.executor = executor;
    }

    @Override
    protected void destroyInstance(T instance) throws Exception {
        instance.shutdown();
    }
}