我在从资产复制数据库时遇到问题。当我的数据库有一个 300KB 的小示例时，它可以正常工作。但是当我的数据库达到 2.5mb 时，发生了错误。创建新的 AVD 后它工作正常。也许是模拟器的SD卡导致错误？因为当我在我的设备中安装我的应用程序时，它正在工作。
这是日志猫所说的：
07-23 18:12:51.522: E/AndroidRuntime(866): Uncaught handler: thread main exiting due to uncaught exception
07-23 18:12:51.531: E/AndroidRuntime(866): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.frux.kfcmobile/com.frux.kfcmobile.KFCmobileActivity}: android.database.sqlite.SQLiteException: no such table: first: , while compiling: SELECT * from first
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.os.Handler.dispatchMessage(Handler.java:99)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.os.Looper.loop(Looper.java:123)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread.main(ActivityThread.java:4363)
07-23 18:12:51.531: E/AndroidRuntime(866): at java.lang.reflect.Method.invokeNative(Native Method)
07-23 18:12:51.531: E/AndroidRuntime(866): at java.lang.reflect.Method.invoke(Method.java:521)
07-23 18:12:51.531: E/AndroidRuntime(866): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
07-23 18:12:51.531: E/AndroidRuntime(866): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
07-23 18:12:51.531: E/AndroidRuntime(866): at dalvik.system.NativeStart.main(Native Method)
07-23 18:12:51.531: E/AndroidRuntime(866): Caused by: android.database.sqlite.SQLiteException: no such table: first: , while compiling: SELECT * from first
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteProgram.native_compile(Native Method)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteProgram.compile(SQLiteProgram.java:110)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:49)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1220)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1193)
07-23 18:12:51.531: E/AndroidRuntime(866): at com.frux.kfcmobile.KFCmobileActivity.onCreate(KFCmobileActivity.java:42)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-23 18:12:51.531: E/AndroidRuntime(866): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
07-23 18:12:51.531: E/AndroidRuntime(866): ... 11 more
这是我的 DBHelper 代码：
public class DatabaseHelper extends SQLiteOpenHelper{
private static String DB_PATH = "/data/data/com.frux.kfcmobile/databases/";
private static String DB_NAME = "database";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static final int DATABASE_VERSION = 1;
public DatabaseHelper(Context context) {
// TODO Auto-generated constructor stub
super(context, DB_NAME, null, DATABASE_VERSION);
this.myContext = context;
}
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
this.getWritableDatabase();
this.close();
}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();
this.close();
try {
copyDataBase();
} catch (IOException e) {
//throw new Error("Error copying database message");
}
}
}
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;
}
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) {
}
}