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> ?
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1Why would you turn something into an array of bytes if you couldn't convert it back? And I don't know why you've accepted the answer you did. As it will not produce a list of strings equal to that which was used to create the byte array.Dunes– Dunes2011-12-15 17:19:56 +00:00Commented Dec 15, 2011 at 17:19
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possible duplicate of What is character encoding and why should I bother with itRaedwald– Raedwald2015-04-10 12:09:26 +00:00Commented Apr 10, 2015 at 12:09
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4 Answers
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();
}
}
}
Comments
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);
}
4 Comments
Brian
Np. Best ask that one as a new question Ali, with more examples of exactly what you're looking to achieve
Sid Malani
@Ali: Do you mean String[] to ArrayList<String> - if so, you can use Arrays.asList
iSun
@SidMalani : No, Just String to ArrayList<String>.
Sid Malani
@Ali Arrays.asList(string.split("")); I am assuming you want to split for each character. It I think will introduce a space in first element which you can easily remove.
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);
Comments
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:
- How can we be sure it's
"US-ASCII"and not"UTF8"or, say,"Cp1251"? - What is the string delimiter?
- 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.
