これが役立つことを願っています
private void getAssetAppFolder(String dir) throws Exception{
{
File f = new File(sdcardlocation + "/" + dir);
if (!f.exists() || !f.isDirectory())
f.mkdirs();
}
AssetManager am=getAssets();
String [] aplist=am.list(dir);
for(String strf:aplist){
try{
InputStream is=am.open(dir+"/"+strf);
copyToDisk(dir,strf,is);
}catch(Exception ex){
getAssetAppFolder(dir+"/"+strf);
}
}
}
public void copyToDisk(String dir,String name,InputStream is) throws IOException{
int size;
byte[] buffer = new byte[2048];
FileOutputStream fout = new FileOutputStream(sdcardlocation +"/"+dir+"/" +name);
BufferedOutputStream bufferOut = new BufferedOutputStream(fout, buffer.length);
while ((size = is.read(buffer, 0, buffer.length)) != -1) {
bufferOut.write(buffer, 0, size);
}
bufferOut.flush();
bufferOut.close();
is.close();
fout.close();
}