Solution for android map app with offline use?

I did an offline map using the ESRI Android SDK and a custom tile layer. I used an ArcGIS server to generate a tile based map cache, then inserted those tiles into a SQLite database and query them based on row and column from there. It works great and if you need custom maps end to end, it is a very usable method.

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;   
}

}

Are you looking for Development for Mobile/Cell App? as the new Google Tablet comes with Offline Google Maps in vector format rather than raster tiles.

Google Honeycomb (Tablet) has full support of Google Maps Offline (Vector)

http://androidandme.com/2010/12/news/andy-rubin-demos-honeycomb-running-on-a-dual-core-motorola-tablet/

Video at the bottom explains and shows the application.

I have developed an application with offline maps for Android. The only free tool you would want to use is OSMDroid, otherwise ESRI. OSMDroid API is identical to Google's, so in case you want to switch from one to another, it's a breeze.

Check out this post, with a sample of how to integrate Google Maps into OSMDroid (it also gives you an idea how to use it in general).