Github user chtyim commented on a diff in the pull request: https://github.com/apache/twill/pull/61#discussion_r137130751 --- Diff: twill-core/src/main/java/org/apache/twill/internal/ResourceReportClient.java --- @@ -0,0 +1,116 @@ +/* + * 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.twill.internal; + +import com.google.common.base.Charsets; +import org.apache.twill.api.ResourceReport; +import org.apache.twill.api.ResourceReporter; +import org.apache.twill.api.TwillRunResources; +import org.apache.twill.internal.json.ResourceReportAdapter; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStreamReader; +import java.io.Reader; +import java.lang.reflect.Type; +import java.net.URL; +import java.util.Collection; +import java.util.Collections; +import java.util.List; +import java.util.Map; +import javax.annotation.Nullable; + +/** + * A {@link ResourceReporter} that fetches reports from the given set of URLs. + */ +public final class ResourceReportClient implements ResourceReporter { + + private static final Logger LOG = LoggerFactory.getLogger(ResourceReportClient.class); + + private final List<URL> resourceUrls; + + public ResourceReportClient(List<URL> resourceUrls) { + this.resourceUrls = resourceUrls; + } + + @Nullable + @Override + public ResourceReport getResourceReport() { + for (URL url : resourceUrls) { + try { + return fetchURL(url, "", ResourceReport.class); + } catch (IOException e) { + // Just log a trace as it's ok to not able to fetch resource report + LOG.trace("Exception raised when getting resource report from {}.", url, e); + } + } --- End diff -- That's the contract of the `ResourceReporter`. If the report is not available for whatever reason, it'll just return `null` / empty collection.
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