我正在尝试附加数据库 - 预填充信息到我的应用程序。我遵循了这个教程here但是当我尝试运行我的数据库助手时，我收到了一个错误。
这是我的帮助代码：
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class WorkoutsDatabaseHelper extends SQLiteOpenHelper {
private String DATABASE_PATH = "/src/main/assets/";
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "workoutsDatabase.db";
// Workouts table name
private static final String TABLE_WORKOUTS = "workouts";
// Workouts Table Columns names
private static final String KEY_ID = "_id";
private static final String KEY_WORKOUT_NAME = "workout_name";
private static final String KEY_HERO_LAST_NAME = "hero_last_name";
private static final String KEY_HERO_FIRST_NAME = "hero_first_name";
private static final String KEY_HERO_MIDDLE_NAME = "hero_middle_name";
private static final String KEY_HERO_DESCRIPTION = "hero_description";
private static final String KEY_DATE_ADDED = "date_added";
private static final String KEY_WORKOUT = "workout";
private static final String KEY_MEASUREMENT = "measurement";
private static final String KEY_PHOTO = "photo";
private SQLiteDatabase myDatabase;
private final Context myContext;
public WorkoutsDatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
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 an 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");
}
}
Log.d("Workouts DB", "Database Created");
}
//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 = DATABASE_PATH + DATABASE_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
} catch(SQLiteException e) {
// Database doesn'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(DATABASE_NAME);
// Path to the just created empty db
String outFileName = DATABASE_PATH + DATABASE_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 android.database.SQLException {
// Open the database
String myPath = DATABASE_PATH + DATABASE_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.
}
这是日志：
04-25 11:03:15.538 11852-11852/com.rcd.mypr D/OpenGLRenderer﹕ Enabling debug mode 0
04-25 11:03:15.610 11852-11852/com.rcd.mypr E/Adreno-ES20﹕ <gl_external_unsized_fmt_to_sized:2379>: QCOM> format, datatype mismatch
04-25 11:03:15.610 11852-11852/com.rcd.mypr E/Adreno-ES20﹕ <get_texture_formats:3009>: QCOM> Invalid format!
04-25 11:03:16.691 11852-11852/com.rcd.mypr E/SQLiteLog﹕ (14) cannot open file at line 30191 of [00bb9c9ce4]
04-25 11:03:16.691 11852-11852/com.rcd.mypr E/SQLiteLog﹕ (14) os_unix.c:30191: (2) open(/src/main/assets/workoutsDatabase.db) -
04-25 11:03:16.702 11852-11852/com.rcd.mypr E/SQLiteDatabase﹕ Failed to open database '/src/main/assets/workoutsDatabase.db'.
android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
at com.rcd.mypr.Workouts.WorkoutsDatabaseHelper.checkDatabase(WorkoutsDatabaseHelper.java:81)
at com.rcd.mypr.Workouts.WorkoutsDatabaseHelper.createDatabase(WorkoutsDatabaseHelper.java:54)
at com.rcd.mypr.Workouts.WorkoutsActivity.onCreate(WorkoutsActivity.java:53)
at android.app.Activity.performCreate(Activity.java:5248)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2173)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2269)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5102)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
04-25 11:03:16.742 11852-11852/com.rcd.mypr D/AndroidRuntime﹕ Shutting down VM
04-25 11:03:16.742 11852-11852/com.rcd.mypr W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x416d4d40)
04-25 11:03:16.745 11852-11852/com.rcd.mypr E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.rcd.mypr, PID: 11852
java.lang.Error: Error copying database
at com.rcd.mypr.Workouts.WorkoutsDatabaseHelper.createDatabase(WorkoutsDatabaseHelper.java:66)
at com.rcd.mypr.Workouts.WorkoutsActivity.onCreate(WorkoutsActivity.java:53)
at android.app.Activity.performCreate(Activity.java:5248)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1110)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2173)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2269)
at android.app.ActivityThread.access$800(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1210)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5102)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
我的数据库名为workoutsDatabase.db，它位于src / main / assets
中任何帮助都将不胜感激。
答案 0 :(得分：1)
显然您正在学习本教程，但您更改了输出数据库的路径名。您不能只选择要放置数据库的任何目录。事实上，对getReadableDatabase的调用将始终在：/ data / data /您的ANDROID MANIFEST /数据库中创建数据包，因此您需要将DATABASEPATH更改为。