Convert byte[] to ArrayList<String>

Question

I found a question here on SO: Convert ArrayList<String> to byte []

It is about converting ArrayList<String> to byte[] .

Now is it possible to convert byte[] to ArrayList<String> ?

Answer 1

Looks like nobody read the original question :)

If you used the method from the first answer to serialize each string separately, doing exactly the opposite will yield the required result:

    ByteArrayInputStream bais = new ByteArrayInputStream(byte[] yourData);
    ObjectInputStream ois = new ObjectInputStream(bais);
    ArrayList<String> al = new ArrayList<String>();
    try {
        Object obj = null;

        while ((obj = ois.readObject()) != null) {
            al.add((String) obj);
        }
    } catch (EOFException ex) { //This exception will be caught when EOF is reached
        System.out.println("End of file reached.");
    } catch (ClassNotFoundException ex) {
        ex.printStackTrace();
    } catch (FileNotFoundException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        //Close the ObjectInputStream
        try {
            if (ois != null) {
                ois.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

If your byte[] contains the ArrayList itself, you can do:

    ByteArrayInputStream bais = new ByteArrayInputStream(byte[] yourData);
    ObjectInputStream ois = new ObjectInputStream(bais);
    try {
        ArrayList<String> arrayList = ( ArrayList<String>) ois.readObject();
        ois.close();
    } catch (EOFException ex) { //This exception will be caught when EOF is reached
        System.out.println("End of file reached.");
    } catch (ClassNotFoundException ex) {
        ex.printStackTrace();
    } catch (FileNotFoundException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    } finally {
        //Close the ObjectInputStream
        try {
            if (ois!= null) {
                ois.close();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

Answer 2

Something like this should suffice, forgive any compile typos I've just rattled it out here:

for(int i = 0; i < allbytes.length; i++)
{
    String str = new String(allbytes[i]);
    myarraylist.add(str);
}

Answer 3

yeah its possible, take each item from byte array and convert to string, then add to arraylist

String str = new String(byte[i]);
arraylist.add(str);

Answer 4

it depends very much on the semantics you expect from such a method. The easiest way would be, new String(bytes, "US-ASCII") —and then split it into the details you want.

There are obviously some problems:

1. How can we be sure it's "US-ASCII" and not "UTF8" or, say, "Cp1251" ?
2. What is the string delimiter?
3. What if we want one of the strings to contain a delimiter?

And so on and so forth. But the easiest way is indeed to call String constructor—it'll be enough to get you started.