+++ /dev/null
-package tim.prune.function.srtm;
-
-import java.io.InputStream;
-import java.net.MalformedURLException;
-import java.net.URL;
-import java.util.ArrayList;
-
-
-/**
- * Class to get the URLs of the SRTM tiles
- * using the srtmtiles.dat file
- */
-public abstract class TileFinder
-{
- /** URL prefix for all tiles */
- private static final String URL_PREFIX = "https://dds.cr.usgs.gov/srtm/version2_1/SRTM3/";
- /** Directory names for each continent */
- private static final String[] CONTINENTS = {"", "Eurasia", "North_America", "Australia",
- "Islands", "South_America", "Africa"};
-
-
- /**
- * Get the Urls for the given list of tiles
- * @param inTiles list of Tiles to get
- * @return array of URLs
- */
- public static URL[] getUrls(ArrayList<SrtmTile> inTiles)
- {
- if (inTiles == null || inTiles.size() < 1) {return null;}
- URL[] urls = new URL[inTiles.size()];
- // Read dat file into array
- byte[] lookup = readDatFile();
- for (int t=0; t<inTiles.size(); t++)
- {
- SrtmTile tile = inTiles.get(t);
- // Get byte from lookup array
- int idx = (tile.getLatitude() + 59)*360 + (tile.getLongitude() + 180);
- try
- {
- int dir = lookup[idx];
- if (dir > 0) {
- try {
- urls[t] = new URL(URL_PREFIX + CONTINENTS[dir] + "/" + tile.getTileName());
- } catch (MalformedURLException e) {} // ignore error, url stays null
- }
- } catch (ArrayIndexOutOfBoundsException e) {} // ignore error, url stays null
- }
- return urls;
- }
-
- /**
- * Read the dat file and get the contents
- * @return byte array containing file contents
- */
- private static byte[] readDatFile()
- {
- InputStream in = null;
- try
- {
- // Need absolute path to dat file
- in = TileFinder.class.getResourceAsStream("/tim/prune/function/srtm/srtmtiles.dat");
- if (in != null)
- {
- byte[] buffer = new byte[in.available()];
- in.read(buffer);
- in.close();
- return buffer;
- }
- }
- catch (java.io.IOException e) {
- System.err.println("Exception trying to read srtmtiles.dat : " + e.getMessage());
- }
- finally
- {
- try {
- in.close();
- }
- catch (Exception e) {} // ignore
- }
- return null;
- }
-}