我希望程序执行时。
要存储在手机中的一些资产文件， 我使用以下方法：
package com.example.copy_external;
public class MainActivity extends ActionBarActivity {
InputStream in;
OutputStream ou;
String path1 = Environment.getExternalStorageDirectory() + "/bbb" + "/" + "source";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Copy_sqlite(path1);
}
public void Copy_sqlite(String address) {
File f1=new File(Environment.getExternalStorageDirectory(),"bbb");
f1.mkdir();
final File f2= new File(address);
try {
in = getBaseContext().getAssets().open("detail.db");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(!f2.exists())
{
try {
try {
f2.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ou = new FileOutputStream(f2 );
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
CopyDB(in, ou);
Toast.makeText(getBaseContext(), "copy", Toast.LENGTH_LONG).show();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}//end
public void CopyDB(InputStream in, OutputStream ou) throws IOException
{
byte []buffer=new byte[1024];
int length;
while((length=in.read(buffer))>0)
{
try {
ou.write(buffer, 0, length);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
in.close();
ou.close();
}
}
此应用程序适用于很多手机。但是 某些型号的手机会出现此错误。 我真的不知道是什么问题？ 我很困惑。
logcat的：（详细）
03-08 23:55:16.054: W/System.err(1403): java.io.IOException: Permission denied
03-08 23:55:16.064: W/System.err(1403): at java.io.File.createNewFileImpl(Native Method)
03-08 23:55:16.064: W/System.err(1403): at java.io.File.createNewFile(File.java:1115)
03-08 23:55:16.064: W/System.err(1403): at com.example.copy_external.MainActivity.Copy_sqlite(MainActivity.java:56)
03-08 23:55:16.064: W/System.err(1403): at com.example.copy_external.MainActivity.onCreate(MainActivity.java:28)
03-08 23:55:16.064: W/System.err(1403): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
03-08 23:55:16.075: W/System.err(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1700)
03-08 23:55:16.075: W/System.err(1403): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1752)
03-08 23:55:16.075: W/System.err(1403): at android.app.ActivityThread.access$1500(ActivityThread.java:123)
03-08 23:55:16.075: W/System.err(1403): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:993)
03-08 23:55:16.084: W/System.err(1403): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 23:55:16.084: W/System.err(1403): at android.os.Looper.loop(Looper.java:126)
03-08 23:55:16.084: W/System.err(1403): at android.app.ActivityThread.main(ActivityThread.java:3997)
03-08 23:55:16.118: W/System.err(1403): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 23:55:16.118: W/System.err(1403): at java.lang.reflect.Method.invoke(Method.java:491)
03-08 23:55:16.118: W/System.err(1403): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
03-08 23:55:16.118: W/System.err(1403): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-08 23:55:16.118: W/System.err(1403): at dalvik.system.NativeStart.main(Native Method)
03-08 23:55:16.118: W/System.err(1403): java.io.FileNotFoundException: /mnt/sdcard/bbb/source (Permission denied)
03-08 23:55:16.124: W/System.err(1403): at org.apache.harmony.luni.platform.OSFileSystem.open(Native Method)
03-08 23:55:16.124: W/System.err(1403): at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:239)
03-08 23:55:16.124: W/System.err(1403): at java.io.FileOutputStream.<init>(FileOutputStream.java:101)
03-08 23:55:16.124: W/System.err(1403): at java.io.FileOutputStream.<init>(FileOutputStream.java:77)
03-08 23:55:16.124: W/System.err(1403): at com.example.copy_external.MainActivity.Copy_sqlite(MainActivity.java:61)
03-08 23:55:16.124: W/System.err(1403): at com.example.copy_external.MainActivity.onCreate(MainActivity.java:28)
03-08 23:55:16.124: W/System.err(1403): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
03-08 23:55:16.124: W/System.err(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1700)
03-08 23:55:16.124: W/System.err(1403): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1752)
03-08 23:55:16.124: W/System.err(1403): at android.app.ActivityThread.access$1500(ActivityThread.java:123)
03-08 23:55:16.124: W/System.err(1403): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:993)
03-08 23:55:16.134: W/System.err(1403): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 23:55:16.134: W/System.err(1403): at android.os.Looper.loop(Looper.java:126)
03-08 23:55:16.134: W/System.err(1403): at android.app.ActivityThread.main(ActivityThread.java:3997)
03-08 23:55:16.134: W/System.err(1403): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 23:55:16.134: W/System.err(1403): at java.lang.reflect.Method.invoke(Method.java:491)
03-08 23:55:16.134: W/System.err(1403): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
03-08 23:55:16.134: W/System.err(1403): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-08 23:55:16.134: W/System.err(1403): at dalvik.system.NativeStart.main(Native Method)
03-08 23:55:16.144: D/AndroidRuntime(1403): Shutting down VM
03-08 23:55:16.144: W/dalvikvm(1403): threadid=1: thread exiting with uncaught exception (group=0x40014760)
03-08 23:55:16.154: E/AndroidRuntime(1403): FATAL EXCEPTION: main
03-08 23:55:16.154: E/AndroidRuntime(1403): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.copy_external/com.example.copy_external.MainActivity}: java.lang.NullPointerException
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1736)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1752)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread.access$1500(ActivityThread.java:123)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:993)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.os.Handler.dispatchMessage(Handler.java:99)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.os.Looper.loop(Looper.java:126)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread.main(ActivityThread.java:3997)
03-08 23:55:16.154: E/AndroidRuntime(1403): at java.lang.reflect.Method.invokeNative(Native Method)
03-08 23:55:16.154: E/AndroidRuntime(1403): at java.lang.reflect.Method.invoke(Method.java:491)
03-08 23:55:16.154: E/AndroidRuntime(1403): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
03-08 23:55:16.154: E/AndroidRuntime(1403): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-08 23:55:16.154: E/AndroidRuntime(1403): at dalvik.system.NativeStart.main(Native Method)
03-08 23:55:16.154: E/AndroidRuntime(1403): Caused by: java.lang.NullPointerException
03-08 23:55:16.154: E/AndroidRuntime(1403): at com.example.copy_external.MainActivity.CopyDB(MainActivity.java:90)
03-08 23:55:16.154: E/AndroidRuntime(1403): at com.example.copy_external.MainActivity.Copy_sqlite(MainActivity.java:69)
03-08 23:55:16.154: E/AndroidRuntime(1403): at com.example.copy_external.MainActivity.onCreate(MainActivity.java:28)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
03-08 23:55:16.154: E/AndroidRuntime(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1700)
03-08 23:55:16.154: E/AndroidRuntime(1403): ... 11 more