我已经在网站上阅读了有关此问题的各种内容，但无法弄清楚。我正在为此应用程序使用预构建数据库。我正在为此应用程序使用 bean 形软糖。
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.quotes"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.quotes.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Logcat输出
根据logcat它是由SQLiteCantOpenDatabaseException引起的
06-10 23:07:01.831: E/Trace(4419): error opening trace file: No such file or directory (2)
06-10 23:07:03.611: E/SQLiteLog(4419): (14) cannot open file at line 30176 of [00bb9c9ce4]
06-10 23:07:03.621: E/SQLiteLog(4419): (14) os_unix.c:30176: (2) open(/data/data/com.example.quotes/databasesQuotesdb) -
06-10 23:07:03.641: E/SQLiteDatabase(4419): Failed to open database '/data/data/com.example.quotes/databasesQuotesdb'.
06-10 23:07:03.641: E/SQLiteDatabase(4419): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at com.example.quotes.DataBaseHelper.checkDataBase(DataBaseHelper.java:94)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at com.example.quotes.DataBaseHelper.createDataBase(DataBaseHelper.java:58)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at com.example.quotes.MainActivity.onCreate(MainActivity.java:34)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.Activity.performCreate(Activity.java:5104)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.os.Handler.dispatchMessage(Handler.java:99)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.os.Looper.loop(Looper.java:137)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at java.lang.reflect.Method.invokeNative(Native Method)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at java.lang.reflect.Method.invoke(Method.java:511)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-10 23:07:03.641: E/SQLiteDatabase(4419): at dalvik.system.NativeStart.main(Native Method)
06-10 23:07:03.731: E/SQLiteLog(4419): (14) cannot open file at line 30176 of [00bb9c9ce4]
06-10 23:07:03.731: E/SQLiteLog(4419): (14) os_unix.c:30176: (2) open(/data/data/com.example.quotes/databasesQuotesdb) -
06-10 23:07:03.781: E/SQLiteDatabase(4419): Failed to open database '/data/data/com.example.quotes/databasesQuotesdb'.
06-10 23:07:03.781: E/SQLiteDatabase(4419): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at com.example.quotes.DataBaseHelper.openDataBase(DataBaseHelper.java:145)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at com.example.quotes.MainActivity.onCreate(MainActivity.java:44)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.Activity.performCreate(Activity.java:5104)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.os.Handler.dispatchMessage(Handler.java:99)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.os.Looper.loop(Looper.java:137)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at java.lang.reflect.Method.invokeNative(Native Method)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at java.lang.reflect.Method.invoke(Method.java:511)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-10 23:07:03.781: E/SQLiteDatabase(4419): at dalvik.system.NativeStart.main(Native Method)
06-10 23:07:03.791: D/AndroidRuntime(4419): Shutting down VM
06-10 23:07:03.791: W/dalvikvm(4419): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
06-10 23:07:03.831: E/AndroidRuntime(4419): FATAL EXCEPTION: main
06-10 23:07:03.831: E/AndroidRuntime(4419): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.quotes/com.example.quotes.MainActivity}: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.os.Handler.dispatchMessage(Handler.java:99)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.os.Looper.loop(Looper.java:137)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-10 23:07:03.831: E/AndroidRuntime(4419): at java.lang.reflect.Method.invokeNative(Native Method)
06-10 23:07:03.831: E/AndroidRuntime(4419): at java.lang.reflect.Method.invoke(Method.java:511)
06-10 23:07:03.831: E/AndroidRuntime(4419): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-10 23:07:03.831: E/AndroidRuntime(4419): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-10 23:07:03.831: E/AndroidRuntime(4419): at dalvik.system.NativeStart.main(Native Method)
06-10 23:07:03.831: E/AndroidRuntime(4419): Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:804)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:789)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:669)
06-10 23:07:03.831: E/AndroidRuntime(4419): at com.example.quotes.DataBaseHelper.openDataBase(DataBaseHelper.java:145)
06-10 23:07:03.831: E/AndroidRuntime(4419): at com.example.quotes.MainActivity.onCreate(MainActivity.java:44)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.Activity.performCreate(Activity.java:5104)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-10 23:07:03.831: E/AndroidRuntime(4419): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
06-10 23:07:03.831: E/AndroidRuntime(4419): ... 11 more
06-10 23:07:04.083: D/dalvikvm(4419): GC_CONCURRENT freed 203K, 11% free 2676K/3000K, paused 25ms+18ms, total 306ms
06-10 23:07:07.811: I/Process(4419): Sending signal. PID: 4419 SIG: 9
DataBaseHelper.java
public class DataBaseHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.example.quotes/databases";
private static String DB_NAME = "Quotesdb";
// Table Names of Data Base.
static final String TABLE_Name = "Quotes";
// Contacts Table Columns names
//private static final String _Id = "_Id";
//private static final String quotes = "quotes";
//private static final String author = "author";
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 DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
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();
SQLiteDatabase db_Read = null;
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.
db_Read = this.getReadableDatabase();
db_Read.close();
try {
copyDataBase();
} catch (IOException e) {
//throw new Error("Error copying database");
e.toString();
}
}
}
/**
* 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) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
}
/*// Getting single contact
public List<Quotes> getQuote(int id) {
ArrayList<Quotes>();
getReadableDatabase();
Cursor cursor = db.query(TABLE_Name, new String[] { _Id,
qotes,author }, _Id + "=?", new String[] { String.valueOf(id) },
null, null, null, null);
//String query = "SELECT _Id, qotes, author From "+TABLE_Name;
//String query = "SELECT * From Quotes";
//Cursor cursor = db.rawQuery(query, null);
if (cursor != null)
cursor.moveToFirst();
Quotes quotes = new Quotes(Integer.parseInt(cursor.getString(0)),
cursor.getString(1),cursor.getString(2));
QuoteList.add(quotes);
return QuoteList;
}
*/
}
最佳答案
将此权限添加到项目的AndroidManifest.xml文件中的manifest标记(应为顶级标记)中。
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />