拷贝asserts资源目录下的文件

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
AssetManager assets = getAssets();
try {
InputStream is = assets.open("hello.txt");
File file = new File("/data/data/" + getPackageName() + "/databases");
if (!file.exists()) {
file.mkdirs();
}
FileOutputStream fos = new FileOutputStream(new File(file, "hello.txt"));
byte[] buff = new byte[1024 * 8];
int len = -1;
while ((len = is.read(buff)) != -1) {
fos.write(buff, 0, len);
}
fos.close();
is.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}