我得到了
open failed: EACCES(权限被拒绝)
myOutput = new FileOutputStream(outFileName);
我检查了根目录，并尝试了android.permission.WRITE_EXTERNAL_STORAGE。
我该如何解决这个问题?
try {
InputStream myInput;
myInput = getAssets().open("XXX.db");
// Path to the just created empty db
String outFileName = "/data/data/XX/databases/"
+ "XXX.db";
// 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();
buffer = null;
outFileName = null;
}
catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
奇怪的是，在我的newFile之前加上斜杠“/”后，我的问题就解决了。我改了这个:
File myFile= new File(Environment.getExternalStorageDirectory() + "newFile");
:
File myFile= new File(Environment.getExternalStorageDirectory() + "/newFile");
更新:
正如评论中提到的，正确的做法是:
File myFile= new File(Environment.getExternalStorageDirectory(), "newFile");
添加gradle依赖项
implementation 'com.karumi:dexter:4.2.0'
在主活动中添加以下代码。
import com.karumi.dexter.Dexter;
import com.karumi.dexter.MultiplePermissionsReport;
import com.karumi.dexter.PermissionToken;
import com.karumi.dexter.listener.PermissionRequest;
import com.karumi.dexter.listener.multi.MultiplePermissionsListener;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
checkMermission();
}
}, 4000);
}
private void checkMermission(){
Dexter.withActivity(this)
.withPermissions(
android.Manifest.permission.READ_EXTERNAL_STORAGE,
android.Manifest.permission.WRITE_EXTERNAL_STORAGE,
android.Manifest.permission.ACCESS_NETWORK_STATE,
Manifest.permission.INTERNET
).withListener(new MultiplePermissionsListener() {
@Override
public void onPermissionsChecked(MultiplePermissionsReport report) {
if (report.isAnyPermissionPermanentlyDenied()){
checkMermission();
} else if (report.areAllPermissionsGranted()){
// copy some things
} else {
checkMermission();
}
}
@Override
public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
token.continuePermissionRequest();
}
}).check();
}
