Tuesday, April 10, 2012

Android: How to copy files in "assets" to sdcard?


I have a few files in the assets folder. I need to copy all of them to a folder say /sdcard/folder. I want to do this from within a thread. How do I do it?



Source: Tips4all

5 comments:

  1. If anyone else is having the same problem, this is how I did it

    private void CopyAssets() {
    AssetManager assetManager = getAssets();
    String[] files = null;
    try {
    files = assetManager.list("");
    } catch (IOException e) {
    Log.e("tag", e.getMessage());
    }
    for(String filename : files) {
    InputStream in = null;
    OutputStream out = null;
    try {
    in = assetManager.open(filename);
    out = new FileOutputStream("/sdcard/" + filename);
    copyFile(in, out);
    in.close();
    in = null;
    out.flush();
    out.close();
    out = null;
    } catch(Exception e) {
    Log.e("tag", e.getMessage());
    }
    }
    }
    private 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);
    }
    }


    Reference : Move file using Java - http://www.java2s.com/Code/Java/File-Input-Output/MoveaFile.htm

    ReplyDelete
  2. Based on your solution, I did something of my own to allow subfolders. Someone might find this helpful:

    ...

    copyFileOrDir("myrootdir");


    ...

    private void copyFileOrDir(String path) {
    AssetManager assetManager = this.getAssets();
    String assets[] = null;
    try {
    assets = assetManager.list(path);
    if (assets.length == 0) {
    copyFile(path);
    } else {
    String fullPath = "/data/data/" + this.getPackageName() + "/" + path;
    File dir = new File(fullPath);
    if (!dir.exists())
    dir.mkdir();
    for (int i = 0; i < assets.length; ++i) {
    copyFileOrDir(path + "/" + assets[i]);
    }
    }
    } catch (IOException ex) {
    Log.e("tag", "I/O Exception", ex);
    }
    }

    private void copyFile(String filename) {
    AssetManager assetManager = this.getAssets();

    InputStream in = null;
    OutputStream out = null;
    try {
    in = assetManager.open(filename);
    String newFileName = "/data/data/" + this.getPackageName() + "/" + filename;
    out = new FileOutputStream(newFileName);

    byte[] buffer = new byte[1024];
    int read;
    while ((read = in.read(buffer)) != -1) {
    out.write(buffer, 0, read);
    }
    in.close();
    in = null;
    out.flush();
    out.close();
    out = null;
    } catch (Exception e) {
    Log.e("tag", e.getMessage());
    }

    }

    ReplyDelete
  3. Good example. Answered my question of how to access files in the assets folder.

    Only change I would suggest is in the for loop. The following format would work too and is preferred:

    for(String filename : files) {
    InputStream in = null;
    OutputStream out = null;
    try {
    in = assetManager.open(filename);
    out = new FileOutputStream("/sdcard/" + filename);
    ...
    }

    ReplyDelete
  4. Use AssetManager, it allows to read the files in the assets. Then use regular Java IO to write the files to sdcard.

    Google is your friend, here's an example.

    ReplyDelete
  5. The solution above did not work due to some errors:


    directory creation did not work
    assets returned by Android contain also three folders: images, sounds and webkit
    Added way to deal with large files: Add extension .mp3 to the file in the assets folder in your project and during copy the target file will be without the .mp3 extension


    Here is the code (I left the Log statements but you can drop them now):

    final static String TARGET_BASE_PATH = "/sdcard/appname/voices/";

    private void copyFilesToSdCard() {
    copyFileOrDir(""); // copy all files in assets folder in my project
    }

    private void copyFileOrDir(String path) {
    AssetManager assetManager = this.getAssets();
    String assets[] = null;
    try {
    Log.i("tag", "copyFileOrDir() "+path);
    assets = assetManager.list(path);
    if (assets.length == 0) {
    copyFile(path);
    } else {
    String fullPath = TARGET_BASE_PATH + path;
    Log.i("tag", "path="+fullPath);
    File dir = new File(fullPath);
    if (!dir.exists() && !path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit"))
    if (!dir.mkdirs());
    Log.i("tag", "could not create dir "+fullPath);
    for (int i = 0; i < assets.length; ++i) {
    String p;
    if (path.equals(""))
    p = "";
    else
    p = path + "/";

    if (!path.startsWith("images") && !path.startsWith("sounds") && !path.startsWith("webkit"))
    copyFileOrDir( p + assets[i]);
    }
    }
    } catch (IOException ex) {
    Log.e("tag", "I/O Exception", ex);
    }
    }

    private void copyFile(String filename) {
    AssetManager assetManager = this.getAssets();

    InputStream in = null;
    OutputStream out = null;
    String newFileName = null;
    try {
    Log.i("tag", "copyFile() "+filename);
    in = assetManager.open(filename);
    if (filename.endsWith(".jpg")) // extension was added to avoid compression on APK file
    newFileName = TARGET_BASE_PATH + filename.substring(0, filename.length()-4);
    else
    newFileName = TARGET_BASE_PATH + filename;
    out = new FileOutputStream(newFileName);

    byte[] buffer = new byte[1024];
    int read;
    while ((read = in.read(buffer)) != -1) {
    out.write(buffer, 0, read);
    }
    in.close();
    in = null;
    out.flush();
    out.close();
    out = null;
    } catch (Exception e) {
    Log.e("tag", "Exception in copyFile() of "+newFileName);
    Log.e("tag", "Exception in copyFile() "+e.toString());
    }

    }

    ReplyDelete