私は自分のアプリで使用する sqlite ファイルを持っています。このチュートリアルに従って、自分の sqlite ファイルを使用します:リンク チュートリアル
このデータベースには多くの座標があり、すべての座標について、アクティビティのフラグメント マップにマークを付けています。デバイス (acer e330) でアプリケーションを起動すると、次のエラーが表示されます。
07-11 16:47:15.928: E/AndroidRuntime(11095): FATAL EXCEPTION: main
07-11 16:47:15.928: E/AndroidRuntime(11095): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.frank.nuova/com.frank.nuova.Offline}: android.database.sqlite.SQLiteException: no such table: linee: , while compiling: SELECT lat, long, via FROM linee
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread.access$600(ActivityThread.java:123)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.os.Handler.dispatchMessage(Handler.java:99)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.os.Looper.loop(Looper.java:137)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread.main(ActivityThread.java:4424)
07-11 16:47:15.928: E/AndroidRuntime(11095): at java.lang.reflect.Method.invokeNative(Native Method)
07-11 16:47:15.928: E/AndroidRuntime(11095): at java.lang.reflect.Method.invoke(Method.java:511)
07-11 16:47:15.928: E/AndroidRuntime(11095): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
07-11 16:47:15.928: E/AndroidRuntime(11095): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
07-11 16:47:15.928: E/AndroidRuntime(11095): at dalvik.system.NativeStart.main(Native Method)
07-11 16:47:15.928: E/AndroidRuntime(11095): Caused by: android.database.sqlite.SQLiteException: no such table: linee: , while compiling: SELECT lat, long, via FROM linee
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:68)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteProgram.compileSql(SQLiteProgram.java:143)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteProgram.compileAndbindAllArgs(SQLiteProgram.java:361)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:127)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:94)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:53)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1564)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1449)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1405)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1485)
07-11 16:47:15.928: E/AndroidRuntime(11095): at com.frank.nuova.DataSource.vediCoordinate(DataSource.java:21)
07-11 16:47:15.928: E/AndroidRuntime(11095): at com.frank.nuova.Offline.onCreate(Offline.java:40)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.Activity.performCreate(Activity.java:4465)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
07-11 16:47:15.928: E/AndroidRuntime(11095): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
07-11 16:47:15.928: E/AndroidRuntime(11095): ... 11 more
しかし、しばらくすると（10秒）動作するので、データベースの正しい座標で地図上に目に見えるマークを付けます。このアプリのデータベースに接続するための同じコードを使用して、自分のデータベースの座標をリストするスピナーを使用しようとしています。しかし、このアプリは以前のアプリと同じエラーですぐにクラッシュします。データベースへの接続の遅延の問題だと思いましたが、可能ですか?
これはアクティビティです:
public class Offline extends Activity {
MyOpenHelper o;
DataSource db;
LatLng pos;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_offline);
o=new MyOpenHelper(this);
try{
o.createDataBase();
}catch (IOException e){
throw new Error("Non posso creare il database");
}
try{
o.openDataBase();
}catch(SQLException sql){
sql.printStackTrace();
}
db=new DataSource(o);
ListView l=(ListView)findViewById(R.id.listView1);
Gps s=new Gps(getApplicationContext());
Location adesso=s.getLocation();
List<LatLng> vicini=db.piuvicino(adesso, db.vediCoordinate());
ArrayAdapter<LatLng> a=new ArrayAdapter<LatLng>(getApplicationContext(),android.R.layout.simple_list_item_1,vicini);
l.setAdapter(a);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.offline, menu);
return true;
}
}
この MyOpenHelper.java
public class MyOpenHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "";
private static String DB_NAME = "orari";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public MyOpenHelper(Context context) {
super(context, DB_NAME, null, 1);// 1? its Database Version
if(android.os.Build.VERSION.SDK_INT >= 4.2){
DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
} else {
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
}
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
// Add your public helper methods to access and get content from the database.
// You could return cursors by doing "return myDataBase.query(....)" so it'd be easy
// to you to create adapters for your views.
}
および DataSource.java
public class DataSource {
private MyOpenHelper oh;
private Cursor cu;
public DataSource(MyOpenHelper o){
oh=o;
}
public List<Coordinate> vediCoordinate(){
SQLiteDatabase db=oh.getReadableDatabase();
String c[]=new String[]{"lat","long","via"};
cu=db.query("linee", c, null, null, null, null, null);
int rows=cu.getCount();
LinkedList<Coordinate> risultato=new LinkedList<Coordinate>();
cu.moveToFirst();
for(int i=0;i<rows;i++){
risultato.add(i,new Coordinate(cu.getDouble(cu.getColumnIndex("lat")),cu.getDouble(cu.getColumnIndex("long")),cu.getString(cu.getColumnIndex("via"))));
cu.moveToNext();
}
cu.close();
return risultato;
}
public double distanza(Location l,LatLng m){
double startlat=l.getLatitude();
double startlon=l.getLongitude();
double endlat=l.getLatitude();
double endlon=l.getLongitude();
float[]res=new float[1];
Location.distanceBetween(startlat, startlon, endlat, endlon, res);
return res[0];
}
public List<LatLng> piuvicino(Location l,List<Coordinate> a){
LatLng b;
double dist=0;
LinkedList <LatLng> lista=new LinkedList<LatLng>();
for(int i=0;i<a.size();i++){
b=new LatLng(a.get(i).getLatitudine(), a.get(i).getLongitudine());
dist=distanza(l,b);
if (dist<0.5){
lista.add(new LatLng(a.get(i).getLatitudine(), a.get(i).getLongitudine()));
}
}
return lista;
}
}