如何正确使用android内部和外部存储？

Question

i am creating Download Manager app therefore my requirement is to store files on sdcard and phone internal storage if sdcard not available and access them later to open files from app. i have read almost every post to store files but it confuses me to decide which method is best to use because there are lot of different ways to do.i want to create folder inside external(if available) or internal then store files inside this folder.
Now here can anyone tell me what is best way to access sdcard if available otherwise internal storage

Answer 1

Storage options in android is the place where you need to go. You will know how to Checking media availability from there, more specifically external storage .

The sample code is

/* Checks if external storage is available for read and write */

public boolean isExternalStorageWritable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state)) {
        return true;
    }
    return false;
}

/* Checks if external storage is available to at least read */

public boolean isExternalStorageReadable() {
    String state = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(state) ||
        Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
        return true;
    }
    return false;
}

Use Environment to access ExternalStorageDirectory