Converting Integer String and int into one another

Here are all the different versions:

a) Convert an Integer to a String

Integer one = Integer.valueOf(1);
String oneAsString = one.toString();

b) Convert an int to a String

int one = 1;
String oneAsString = String.valueOf(one);

c) Convert a String to an Integer

String oneAsString = "1";
Integer one = Integer.valueOf(oneAsString);

d) Convert a String to an int

String oneAsString = "1";
int one = Integer.parseInt(oneAsString);