Just some methods and their uses.

Integer intObj1 = Integer.valueOf(String s);

returns a wrapper object corresponding to the to the primitive
value represented by the String object passed as an arguement.

Also as crptcblade pointed out. There are two parstInt() methods
within the Integer class. If you interested in numbering systems

public static int parseInt(String s);
public static int parseInt(String s, int radix);

you can also use:

public static String toHexString(int i);