CoverageMaximumValueSelectionStrategyImpl.java

/* (c) 2014 - 2016 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2014 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.wms.dimension.impl;

import java.io.IOException;
import java.util.Collections;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.geoserver.catalog.CoverageInfo;
import org.geoserver.catalog.DimensionInfo;
import org.geoserver.catalog.ResourceInfo;
import org.geoserver.catalog.util.ReaderDimensionsAccessor;
import org.geoserver.wms.dimension.AbstractDefaultValueSelectionStrategy;
import org.geotools.coverage.grid.io.GridCoverage2DReader;
import org.geotools.util.Converters;
import org.geotools.util.logging.Logging;

/**
 * Default implementation for selecting the default values for dimensions of 
 * coverage (raster) resources using the maximum domain value strategy.
 *  
 * @author Ilkka Rinne / Spatineo Inc for the Finnish Meteorological Institute
 *
 */
public class CoverageMaximumValueSelectionStrategyImpl extends AbstractDefaultValueSelectionStrategy {
    private static Logger LOGGER = Logging.getLogger(CoverageMaximumValueSelectionStrategyImpl.class);
    
    /**
     * Default constructor.
     */
    public CoverageMaximumValueSelectionStrategyImpl() {
    }

    @Override
    public Object getDefaultValue(ResourceInfo resource, String dimensionName,
            DimensionInfo dimension, Class clz) {
        Object retval = null;
        try {
            GridCoverage2DReader reader = (GridCoverage2DReader) ((CoverageInfo) resource)
                    .getGridCoverageReader(null, null);
            ReaderDimensionsAccessor dimAccessor = new ReaderDimensionsAccessor(reader);
           
            if (dimensionName.equals(ResourceInfo.TIME)) {
                retval = dimAccessor.getMaxTime();
            } else if (dimensionName.equals(ResourceInfo.ELEVATION)) {
                retval = dimAccessor.getMaxElevation();
            } else if (dimensionName.startsWith(ResourceInfo.CUSTOM_DIMENSION_PREFIX)){
                String custDimName = dimensionName.substring(ResourceInfo.CUSTOM_DIMENSION_PREFIX.length());
                // see if we have an optimize way to get the minimum
                String maximum = reader.getMetadataValue(custDimName.toUpperCase()
                        + "_DOMAIN_MAXIMUM");
                if (maximum != null) {
                    retval = maximum;
                }
                else {
                    // ok, get the full domain then
                    List<String> domain = dimAccessor.getDomain(custDimName);

                    if (domain.isEmpty()) {
                        retval = null;
                    } else {
                        //Just a lexical (string) sort. 
                        //Should we be prepared for numeric and date values?
                        Collections.sort(domain);
                        retval = domain.get(domain.size() - 1);
                    }
                }
            }

        } catch (IOException e) {
            LOGGER.log(Level.FINER, e.getMessage(), e);
        }            
        return Converters.convert(retval, clz);
    }          
}