我正在尝试与本教程中的相同： http ://www.reigndesign.com/blog/using-your-own-sqlite-database-in-android-applications/ 但我面临一些困难。这是我的课：
public class TechAgrumeSQLiteHelper extends SQLiteOpenHelper {
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/test.test.test/databases/";
private static String DB_NAME = "Player_Club";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static final String TABLE_PLAYERS = "Player";
private static final int DATABASE_VERSION = 3;
// Contacts Table Columns names
private static final String KEY_CODE = "_id";
private static final String KEY_NOM = "nom_Player";
private static final String KEY_SURNOM = "surnom_Player";
private static final String KEY_AGE = "age_Player";
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public TechAgrumeSQLiteHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
Log.d("I'm here: ","I'm here!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
Log.d("Copy BD","database already exists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
}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();
Log.d("Copy BD","Datbase copied!!!!!!!!!!!!!!!!!!!!!!!!!!!");
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
}
/**
* 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_READONLY);
}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_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
// 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.
void addPlayer(Player player) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NOM, player.getNom_Player()); // Contact Name
values.put(KEY_SURNOM, player.getSurnom_Player()); // Contact Phone
values.put(KEY_AGE, player.getAge_Player()); // Contact Phone
// Inserting Row
db.insert(TABLE_PLAYERS, null, values);
db.close(); // Closing database connection
}
public List<Player> getAllPlayers() {
List<Player> playerList = new ArrayList<Player>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_PLAYERS;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Player player = new Player();
player.setCode_Player(Integer.parseInt(cursor.getString(0)));
player.setNom_Player(cursor.getString(1));
player.setSurnom_Player(cursor.getString(2));
player.setAge_Player(Integer.parseInt(cursor.getString(3)));
// Adding contact to list
playerList.add(player);
} while (cursor.moveToNext());
}
// return contact list
return playerList;
}
}
这是 MainActivity 类：
public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TechAgrumeSQLiteHelper db=new TechAgrumeSQLiteHelper(this);
//this.deleteDatabase("Player_Club.db");
// Inserting Contacts
Log.d("Insert: ", "Inserting ................................................");
db.addPlayer(new Player("nom1", "prénom1",25));
db.addPlayer(new Player("nom2", "prénom2",24));
db.addPlayer(new Player("nom3", "prénom3",26));
db.addPlayer(new Player("nom4", "prénom4",16));
// Reading all contacts
Log.d("Reading: ", "Reading all contacts..");
List<Player> player = db.getAllPlayers();
for (Player cn : player) {
String log = "Id: "+cn.getCode_Player()+" ,Name: " + cn.getNom_Player() + " ,Phone: " + cn.getSurnom_Player()+" ,Age: "+cn.getAge_Player();
// Writing Contacts to log
Log.d("Name: ", log);}}
}
它给了我这个错误：
D/I'm here: ( 6548): I'm here!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
D/KeyguardViewMediator( 216): setHidden false
D/Copy BD( 6548): database already exists!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
D/Insert: ( 6548): Inserting ................................................
I/SqliteDatabaseCpp( 6548): sqlite returned: error code = 1, msg = no such table: Player, db=/data/data/test.test.test/databases/webview.db
E/SQLiteDatabase( 6548): Error during inserting
E/SQLiteDatabase( 6548): android.database.sqlite.SQLiteException: no such table: Player: , while compiling: INSERT INTO Player(surnom_Player,nom_Player,age_Player) VALUES (?,?,?)
我去看看 Player_Club.db 是否真的存在：
adb shell
shell@android:/ $ run-as test.test.test
run-as test.test.test
<a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a> $ cd /data/data/test.test.test/databases
.test.test/databases <
<a href="mailto:shell@android:/data/data/test.test.test">shell@android:/data/data/test.test.test</a>/databases $ ls
ls
Player_Club.db
webview.db
webview.db-shm
webview.db-wal
从这些行我可以看出数据库确实存在，所以我不知道它为什么要在 webview.db 上寻找 Player 表？