org.apache.ambari.view.weather.CityResourceProvider.java Source code

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Here is the source code for org.apache.ambari.view.weather.CityResourceProvider.java

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/**
 * 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.ambari.view.weather;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import org.apache.ambari.view.NoSuchResourceException;
import org.apache.ambari.view.ReadRequest;
import org.apache.ambari.view.ResourceAlreadyExistsException;
import org.apache.ambari.view.ResourceProvider;
import org.apache.ambari.view.SystemException;
import org.apache.ambari.view.UnsupportedPropertyException;
import org.apache.ambari.view.ViewContext;
import org.apache.commons.io.IOUtils;
import org.apache.http.client.utils.URIBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.inject.Inject;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Type;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * Resource provider for city resource of the weather view.
 */
public class CityResourceProvider implements ResourceProvider<CityResource> {

    /**
     * The logger.
     */
    protected final static Logger LOG = LoggerFactory.getLogger(CityResourceProvider.class);

    /**
     * The view context.
     */
    @Inject
    ViewContext viewContext;

    // ----- ResourceProvider --------------------------------------------------

    @Override
    public CityResource getResource(String resourceId, Set<String> propertyIds)
            throws SystemException, NoSuchResourceException, UnsupportedPropertyException {

        Map<String, String> properties = viewContext.getProperties();

        String units = properties.get("units");

        try {
            return getResource(resourceId, units, propertyIds);
        } catch (IOException e) {
            throw new SystemException("Can't get city resource " + resourceId + ".", e);
        }
    }

    @Override
    public Set<CityResource> getResources(ReadRequest request)
            throws SystemException, NoSuchResourceException, UnsupportedPropertyException {

        Set<CityResource> resources = new HashSet<CityResource>();

        Map<String, String> properties = viewContext.getProperties();

        String units = properties.get("units");
        String cityStr = properties.get("cities");
        String[] cities = cityStr.split(";");

        for (String city : cities) {
            try {
                resources.add(getResource(city, units, request.getPropertyIds()));
            } catch (IOException e) {
                throw new SystemException("Can't get city resource " + city + ".", e);
            }
        }
        return resources;
    }

    @Override
    public void createResource(String resourceId, Map<String, Object> stringObjectMap) throws SystemException,
            ResourceAlreadyExistsException, NoSuchResourceException, UnsupportedPropertyException {
        throw new UnsupportedOperationException("Creating city resources is not currently supported");
    }

    @Override
    public boolean updateResource(String resourceId, Map<String, Object> stringObjectMap)
            throws SystemException, NoSuchResourceException, UnsupportedPropertyException {
        throw new UnsupportedOperationException("Updating city resources is not currently supported");
    }

    @Override
    public boolean deleteResource(String resourceId)
            throws SystemException, NoSuchResourceException, UnsupportedPropertyException {
        throw new UnsupportedOperationException("Deleting city resources is not currently supported");
    }

    // ----- helper methods ----------------------------------------------------

    // Get a city resource from the given id.
    private CityResource getResource(String resourceId, String units, Set<String> propertyIds) throws IOException {
        CityResource resource = new CityResource();

        resource.setId(resourceId);
        resource.setUnits(units);
        if (isWeatherRequested(propertyIds)) {
            resource.setWeather(getWeatherProperty(resourceId, units));
        }
        return resource;
    }

    // Determine whether the weather property has been requested.
    private boolean isWeatherRequested(Set<String> propertyIds) {

        for (String propertyId : propertyIds) {
            if (propertyId.startsWith("weather")) {
                return true;
            }
        }
        return false;
    }

    // Populate the weather property.
    private Map<String, Object> getWeatherProperty(String city, String units) throws IOException {
        URIBuilder uriBuilder = new URIBuilder();
        uriBuilder.setScheme("http");
        uriBuilder.setHost("api.openweathermap.org");
        uriBuilder.setPath("/data/2.5/weather");
        uriBuilder.setParameter("q", city);
        uriBuilder.setParameter("units", units);

        String url = uriBuilder.toString();

        InputStream in = readFrom(url);
        try {
            Type mapType = new TypeToken<Map<String, Object>>() {
            }.getType();
            Map<String, Object> results = new Gson().fromJson(IOUtils.toString(in, "UTF-8"), mapType);

            ArrayList list = (ArrayList) results.get("weather");
            if (list != null) {
                Map weather = (Map) list.get(0);
                results.put("weather", weather);
                results.put("icon_src", "http://openweathermap.org/img/w/" + weather.get("icon"));
            }
            return results;
        } finally {
            in.close();
        }
    }

    // Get an input stream from the given URL spec.
    private static InputStream readFrom(String spec) throws IOException {
        URLConnection connection = new URL(spec).openConnection();

        connection.setConnectTimeout(5000);
        connection.setDoOutput(true);
        return connection.getInputStream();
    }
}