J'ai créé une carte hors ligne à l'aide du SDK Android ESRI et d'une couche de tuiles personnalisée. J'ai utilisé un serveur ArcGIS pour générer un cache de carte basé sur des tuiles, puis j'ai inséré ces tuiles dans une base de données SQLite et les ai interrogées en fonction de la ligne et de la colonne à partir de là. Cela fonctionne très bien et si vous avez besoin de cartes personnalisées de bout en bout, c'est une méthode très utilisable.
package com.main.utilinspect;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.List;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonParser;
import android.content.Context;
import android.util.Log;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import com.esri.core.internal.c.d;
import com.esri.core.internal.c.h;
import com.esri.core.internal.c.l;
import com.esri.android.map.TiledServiceLayer;
public class OfflineDbTiledLayer extends TiledServiceLayer {
File workingDirectory;
String mapDefinition;
String databaseName;
private SQLiteDatabase database;
File blankImage;
byte[] blankImageBytes;
private final Object lock = new Object();
private static final String TAG = "OfflineTiledLayer";
public OfflineDbTiledLayer(Context paramContext, File workingDirectory, String mapDefinition, String databaseName) {
super("required");
this.workingDirectory = workingDirectory;
this.mapDefinition = mapDefinition;
this.databaseName = databaseName;
String databasePath = workingDirectory.getAbsolutePath() + File.separator + databaseName;
this.database = SQLiteDatabase.openDatabase(databasePath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
this.blankImage = new File(workingDirectory.getAbsolutePath() + File.separator + "blank.png");
RandomAccessFile raFile = null;
try {
raFile = new RandomAccessFile(this.blankImage, "r");
blankImageBytes = new byte[(int) raFile.length()];
raFile.readFully(blankImageBytes);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally {
if(raFile != null) {
try {
raFile.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
h h1 = null;
try
{
JsonParser paramJsonParser = new JsonFactory()
.createJsonParser(new File(workingDirectory.getAbsolutePath() + File.separator + mapDefinition));
paramJsonParser.nextToken();
h1 = h.a(paramJsonParser, "test");
}
catch(Exception ex){
}
setFullExtent(h1.f());
setDefaultSpatialReference(h1.c());
setInitialExtent(h1.e());
l l1;
List list;
int i;
double ad[] = new double[i = (list = (l1 = h1.d()).h).size()];
double ad1[] = new double[i];
for(int j = 0; j < list.size(); j++)
{
ad[j] = ((d)list.get(j)).b();
ad1[j] = ((d)list.get(j)).a();
}
setTileInfo(new com.esri.android.map.TiledServiceLayer.TileInfo(l1.f, ad, ad1, i, l1.c, l1.b, l1.a));
super.initLayer();
return;
}
private void openDatabase(){
if(!database.isOpen()){
String databasePath = workingDirectory.getAbsolutePath() + File.separator + databaseName;
this.database = SQLiteDatabase.openDatabase(databasePath, null, SQLiteDatabase.NO_LOCALIZED_COLLATORS);
}
}
private void closeDatabase(){
if(database.isOpen()){
this.database.close();
}
}
@Override
protected byte[] getTile(int level, int column, int row) throws Exception {
byte[] tileImage;
Log.i(TAG, "getTile");
Log.i(TAG, "getTile - retrieving tile");
synchronized(lock) {
Log.i(TAG, "getTile - entered synchronized block");
openDatabase();
// First check to see if the tile exists in the database
Cursor tileCursor = database.rawQuery("SELECT image FROM tiles WHERE level = " + Integer.toString(level) + " AND row = " + Integer.toString(row) + " AND column = " + Integer.toString(column), null);
if(tileCursor != null && tileCursor.getCount() > 0) {
tileCursor.moveToFirst();
tileImage = tileCursor.getBlob(0);
Log.i(TAG, "getTile - tile found, returning image");
}
else {
// The tile does not exist in the database, read the blank placeholder tile and serve it
tileImage = blankImageBytes;
Log.i(TAG, "getTile - tile not found returning blank");
}
tileCursor.close();
this.database.close();
}
Log.i(TAG, "getTile - exited synchronized block");
return tileImage;
}
}