com.continuuity.weave.yarn.ResourceReportClient.java Source code

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Here is the source code for com.continuuity.weave.yarn.ResourceReportClient.java

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/*
 * Copyright 2012-2013 Continuuity,Inc.
 *
 * 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 com.continuuity.weave.yarn;

import com.continuuity.weave.api.ResourceReport;
import com.continuuity.weave.internal.json.ResourceReportAdapter;
import com.google.common.base.Charsets;
import com.google.common.io.Closeables;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;

/**
 * Package private class to get {@link ResourceReport} from the application master.
 */
final class ResourceReportClient {
    private static final Logger LOG = LoggerFactory.getLogger(ResourceReportClient.class);

    private final ResourceReportAdapter reportAdapter;
    private final URL resourceUrl;

    ResourceReportClient(URL resourceUrl) {
        this.resourceUrl = resourceUrl;
        this.reportAdapter = ResourceReportAdapter.create();
    }

    /**
     * Returns the resource usage of the application fetched from the resource endpoint URL.
     * @return A {@link ResourceReport} or {@code null} if failed to fetch the report.
     */
    public ResourceReport get() {
        try {
            Reader reader = new BufferedReader(new InputStreamReader(resourceUrl.openStream(), Charsets.UTF_8));
            try {
                return reportAdapter.fromJson(reader);
            } finally {
                Closeables.closeQuietly(reader);
            }
        } catch (Exception e) {
            LOG.error("Exception getting resource report from {}.", resourceUrl, e);
            return null;
        }
    }
}