Extending a tile source provider

The TileSourceProvider class. Custom tile format can be encapsulated as tile source for tiling, which possess the capability of creating and loading tileset and allows users to store tile as the extended format during tiling.

During extension, the TileSourceProvider class must be created under the com.supermap.services.tilesource.impl package. Otherwise, the tile format will not be able to be found during distributed tiling after deployment. The extension is as follows:

@TileSourceProviderAnnotation Labels the TileSourceInfo class, name, whether the tile is stored locally or not. infoType indicates tile source corresponding to the current tile provider, which is NationalCacheStandardTileSourceInfo Extended in Previous Section for this example. isLocal represents the storage type, with true indicating local disk storage and false indicating distributed storage.

During extension, unimplemented methods in the AbstractTileSourceProvider class should be noticed, including:

package com.supermap.services.tilesource.impl;
import static org.apache.commons.lang3.StringUtils.isEmpty;
import java.io.File;
import java.util.Collection;
import java.util.concurrent.ConcurrentHashMap;
import com.supermap.services.tilesource.ImageMetaData;
import com.supermap.services.tilesource.ImageTileInfo;
import com.supermap.services.tilesource.MetaData;
import com.supermap.services.tilesource.NationalCacheStandardTileSourceInfo;
import com.supermap.services.tilesource.TileSourceProviderAnnotation;
import com.supermap.services.tilesource.Tileset;
/**
 *
 * The provider corresponding to the map tile source
 *
 */
@TileSourceProviderAnnotation(infoType = com.supermap.services.tilesource.NationalCacheStandardTileSourceInfo.class, name = "NationalMap", isLocal = true)
public class NationalCacheStandardTileSourceProvider extends AbstractTileSourceProvider<NationalCacheStandardTileSourceInfo> {
        //Create tileset of standard format
    private ConcurrentHashMap<String, NationalCacheStandardTileset> tilesets = new ConcurrentHashMap<String, NationalCacheStandardTileset>();
    private File outputFile;
    @Override
    protected boolean doConnect(NationalCacheStandardTileSourceInfo tilesourceInfo) {
        String outputPath = tilesourceInfo.getOutputPath();
        if (isEmpty(outputPath)) {
            return false;
        }
        //Create tile storage directory
        outputFile = new File(outputPath);
        if (!outputFile.exists()) {
            outputFile.mkdirs();
        }
        //Store tiles to created directory
        File[] files = outputFile.listFiles();
        for (File file : files) {
            if (file.isDirectory()) {
                NationalCacheStandardTileset tileset = new NationalCacheStandardTileset(file);
                tilesets.put(tileset.getName(), tileset);
            }
        }
        return true;
    }
    //Cereate Tileset
    @Override
    protected Tileset<ImageMetaData, ImageTileInfo> doCreateTileset(MetaData metaData) {
        if (!(metaData instanceof ImageMetaData)) {
            throw new IllegalArgumentException("NationalCacheStandard TileSource only support ImageMetaData");
        }
        NationalCacheStandardTileset tileset = new NationalCacheStandardTileset(new File(outputFile, metaData.mapName));
        tilesets.put(tileset.getName(), tileset);
        return tileset;
    }
    //Create the connection to clear all Tilesets
    @Override
    protected boolean doDisConnect() {
        this.tilesets.clear();
        this.outputFile = null;
        return true;
    }
    //Get Tileset according to name
    @Override
    public Tileset<ImageMetaData, ImageTileInfo> getTileset(String name) {
        return tilesets.get(name);
    }
    //Get Tileset collection in Provider
    @Override
    public Tileset<ImageMetaData, ImageTileInfo>[] getTilesets() {
        Collection<NationalCacheStandardTileset> tilesets = this.tilesets.values();
        int size = tilesets.size();
        NationalCacheStandardTileset[] tilesetArray = new NationalCacheStandardTileset[size];
        tilesets.toArray(tilesetArray);
        return tilesetArray;
    }
    //Refresh the operation to load Tilesets that have not been loaded in the folder
    @Override
    public void refresh() {
        if (!connected.get()) {
            return;
        }
        try {
            lock.lock();
            File[] files = outputFile.listFiles();
            for (File file : files) {
                if (file.isDirectory()) {
                    NationalCacheStandardTileset tileset = new NationalCacheStandardTileset(file);
                    if (!tilesets.containsKey(tileset.getName())) {
                        tilesets.put(tileset.getName(), tileset);
                    }
                }
            }
        } finally {
            lock.unlock();
        }
    }
    //Acquire Tileset corresponding to MetaData. Determin whether it is matched Tilset according to map name
    @Override
    protected Tileset<?, ?> getCompatibleTileset(MetaData metaData) {
        if ((!(metaData instanceof ImageMetaData)) || metaData.mapName == null) {
            return null;
        }
        Collection<NationalCacheStandardTileset> tilesets = this.tilesets.values();
        for (NationalCacheStandardTileset tileset : tilesets) {
            if (tileset == null) {
                continue;
            }
            if (metaData.mapName.equals(tileset.getCacheName())) {
                return tileset;
            }
        }
        return null;
    }
}

Field/Method	Description
protected boolean doConnect(NationalCacheStandardTileSourceInfo tilesourceInfo)	Create and connect storage path to store tiles to the path.
protected Tileset<ImageMetaData, ImageTileInfo> doCreateTileset(MetaData metaData)	Create a tileset.
public Tileset<ImageMetaData, ImageTileInfo>[] getTilesets()	Get the Tileset collection in Provider.
public Tileset<ImageMetaData, ImageTileInfo> getTileset(String name)	Get a tileset according to the name.
public void refresh()	Refresh the opeation to load Tileset that has not been loaded in folder.
protected boolean doDisConnect()	Break the connection to clear all tilesets.