Use SRTM 1deg data from NASA servers

[GpsPrune.git] / src / tim / prune / function / srtm / Srtm3Source.java

diff --git a/src/tim/prune/function/srtm/Srtm3Source.java b/src/tim/prune/function/srtm/Srtm3Source.java
new file mode 100644 (file)
index 0000000..14fad59
--- /dev/null
+++ b/src/tim/prune/function/srtm/Srtm3Source.java
@@ -0,0 +1,164 @@
+package tim.prune.function.srtm;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.HttpURLConnection;
+
+import tim.prune.GpsPrune;
+import tim.prune.I18nManager;
+
+public class Srtm3Source extends SrtmSource {
+       /** 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"};
+       private byte[] _continents_lookup;
+
+
+       public Srtm3Source()
+       {
+               _continents_lookup = populateContinents();
+       }
+
+       public String getNameKey()
+       {
+               return "function.downloadsrtm." + getName();
+       }
+
+       public String getName()
+       {
+               return "SRTM3_v21";
+       }
+
+       protected String getSourceExtension()
+       {
+               return ".hgt.zip";
+       }
+
+       /**
+        * Read the dat file and get the contents
+        * @return byte array containing file contents
+        */
+       private static byte[] populateContinents()
+       {
+               InputStream in = null;
+               try
+               {
+                       // Need absolute path to dat file
+                       in = Srtm3Source.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;
+       }
+
+       /**
+        * Get the Url for the given tile
+        * @param inTile Tile to get
+        * @return URL
+        */
+       private URL buildUrl(SrtmTile inTile)
+               throws SrtmSourceException
+       {
+               
+               // Get byte from lookup array
+               int idx = (inTile.getLatitude() + 59)*360 + (inTile.getLongitude() + 180);
+               int dir;
+               try
+               {
+                       dir = _continents_lookup[idx];
+               }
+               catch (ArrayIndexOutOfBoundsException e)
+               {
+                       throw new SrtmSourceException("Could not find continent for tile "+inTile.getTileName());
+               }
+               try
+               {
+                       return new URL(URL_PREFIX + CONTINENTS[dir] + "/" + inTile.getTileName() + getSourceExtension());
+               }
+               catch (MalformedURLException e)
+               {
+                       throw new SrtmSourceException("Could not build URL for tile "+inTile.getTileName());
+               }
+       }
+
+       public boolean isReadyToUse()
+       {
+               return true;
+       }
+
+       public boolean downloadTile(SrtmTile inTile)
+               throws SrtmSourceException
+       {
+               int redirects = 5;
+               URL tileUrl = buildUrl(inTile);
+               File outputFile = getCacheFileName(inTile);
+               System.out.println("Download: Need to download: " + tileUrl);
+
+               try
+               {
+                       HttpURLConnection conn = (HttpURLConnection) tileUrl.openConnection();
+
+                       // Define streams
+                       FileOutputStream outStream = null;
+                       InputStream inStream = null;
+
+                       conn.setRequestProperty("User-Agent", "GpsPrune v" + GpsPrune.VERSION_NUMBER);
+
+                       int status = conn.getResponseCode();
+                       if (status == 200)
+                       {
+                               inStream = conn.getInputStream();
+                       }
+                       else if (status == 404)
+                       {
+                               throw new SrtmSourceException("Tile not found: "+conn.getURL());
+                       }
+                       else
+                       {
+                               throw new SrtmSourceException("Invalid response from server: " +status+conn.getContent());
+                       }
+
+                       outStream = new FileOutputStream(outputFile);
+
+                       int c;
+                       while ((c = inStream.read()) != -1)
+                       {
+                               outStream.write(c);
+                       }
+                       // Make sure streams are closed
+                       try {inStream.close();} catch (Exception e) {}
+                       try {outStream.close();} catch (Exception e) {}
+                       return true;
+               }
+               catch (IOException e)
+               {
+                       throw new SrtmSourceException("Error while downloading tile "+inTile.getTileName()+": "+e.getMessage());
+               }
+       }
+
+       public int getRowSize(SrtmTile inTile)
+       {
+               return 1201;
+       }
+}