I'm trying to create a android app.
I use InputStream inputStream=getAssets().open("book.txt");
to read the book.txt
;
I just want get the MappedByteBuffer object from InputStream ;
who konws?
========= ===========
I use FileInputStream fis = (FileInputStream) inputStream;
cause an error! here is the error log:
10-27 10:45:55.830: D/dalvikvm(9243): GC_EXTERNAL_ALLOC freed 22K, 53% free 2577K/5379K, external 1916K/2428K, paused 62ms 10-27 10:45:55.940: D/dalvikvm(9243): GC_EXTERNAL_ALLOC freed 2K, 53% free 2577K/5379K, external 2516K/2516K, paused 69ms 10-27 10:45:56.230: I/fileName(9243): sahala.txt 10-27 10:45:56.240: D/szipinf(9243): Initializing inflate state 10-27 10:45:56.240: D/AndroidRuntime(9243): Shutting down VM 10-27 10:45:56.240: W/dalvikvm(9243): threadid=1: thread exiting with uncaught exception (group=0x40015560) 10-27 10:45:56.260: E/AndroidRuntime(9243): FATAL EXCEPTION: main 10-27 10:45:56.260: E/AndroidRuntime(9243): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.silenceper.bookdemo/com.silenceper.book.shl.activity.ReadBookActivity}: java.lang.ClassCastException: android.content.res.AssetManager$AssetInputStream 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread.access$1500(ActivityThread.java:117) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.os.Handler.dispatchMessage(Handler.java:99) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.os.Looper.loop(Looper.java:123) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread.main(ActivityThread.java:3683) 10-27 10:45:56.260: E/AndroidRuntime(9243): at java.lang.reflect.Method.invokeNative(Native Method) 10-27 10:45:56.260: E/AndroidRuntime(9243): at java.lang.reflect.Method.invoke(Method.java:507) 10-27 10:45:56.260: E/AndroidRuntime(9243): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 10-27 10:45:56.260: E/AndroidRuntime(9243): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 10-27 10:45:56.260: E/AndroidRuntime(9243): at dalvik.system.NativeStart.main(Native Method) 10-27 10:45:56.260: E/AndroidRuntime(9243): Caused by: java.lang.ClassCastException: android.content.res.AssetManager$AssetInputStream 10-27 10:45:56.260: E/AndroidRuntime(9243): at com.silenceper.book.shl.utils.BookPageFactory.openBookFromInputStream(BookPageFactory.java:83) 10-27 10:45:56.260: E/AndroidRuntime(9243): at com.silenceper.book.shl.activity.ReadBookActivity.initBookData(ReadBookActivity.java:71) 10-27 10:45:56.260: E/AndroidRuntime(9243): at com.silenceper.book.shl.activity.ReadBookActivity.onCreate(ReadBookActivity.java:58) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 10-27 10:45:56.260: E/AndroidRuntime(9243): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 10-27 10:45:56.260: E/AndroidRuntime(9243): ... 11 more
Updated
To do this you need to first copy your asset to a file and then apply the technique below to a file. If your asset is more than 1MB you will require to split it - Load files bigger than 1M from assets folder
You can't do this with an InputStream
. You should instead get a FileInputStream
for your book.txt
or cast your inputStream
and then get a FileChannel
from it:
try {
FileInputStream fis = (FileInputStream) inputStream;
FileChannel channel = fis.getChannel();
ByteBuffer buffer = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
byte[] bytes = new byte[102];
buffer.get(bytes);
System.out.println(new String(bytes));
} catch (IOException e) {
e.printStackTrace();
}
I had the similar need of doing this. Here is what I did:
1) Open resource file with asset manager and write a regular file to /data/data/com.yourpackage/files directory. Sample code:
private void prepareModelFile() throws IOException {
AssetManager assetManager = getAssets();
String configDir = getFilesDir().getAbsolutePath();
InputStream stream = assetManager.open("mytestfile_in_assets.data");
mTFLiteModelFile = configDir +"/mytestfilename.data";
OutputStream output = new BufferedOutputStream(new FileOutputStream(mTFLiteModelFile));
copyFile(stream, output);
}
public static void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1) {
out.write(buffer, 0, read);
}
in.close();;
out.close();
}
2) Now you have the file copied out of assets, you can use the following way to create a MappedByteBuffer. Example:
FileInputStream inputStream = new FileInputStream(mTFLiteModelFile);
FileChannel fileChannel = inputStream.getChannel();
MappedByteBuffer myMappedBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel.size());
Hope this helps.
David
由于许多原因,您无法执行此操作,其中大多数都暗示该问题没有道理。
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