Need help with errors (Queue and Stack)

Question

can someone please help. I am getting these errors and i do not know what's wrong or how to fix them. A snippet from the program is below following is the errors I am getting. Please help. :(
public class test
private Stack opStack;
private Queue postfix;
private StringTokenizer str;
private String curValue;
public void Parser(String s)
opStack = new StackAr();
postfix = new QueueAr();
str = new StringTokenizer(s, "+-/*^() ", true);
opStack.push(new Integer(END));
class QueueAr implements Queue
private Object array[];
private int count, front, back;
static final int DEF_SIZE = 15;
private int increment (int x)
test.java:24: Variable DEF_SIZE can't be static in inner class test. QueueAr. Only members of interfaces and top-level classes can be static.
class QueueAr implements Queue
^
test.java:24: Interface Queue of inner class test. QueueAr not found.
class QueueAr implements Queue
^
test.java:12: Class Queue not found in type declaration.
private Queue postfix;
^
test.java:18: Class StackAr not found in type declaration.
opStack = new StackAr();

Answer 1

test.java:24: Variable DEF_SIZE can't be static in
inner class test. QueueAr. Only members of interfaces
and top-level classes can be static.
class QueueAr implements Queue
^You can't have static members in an inner class. Either Move DEF_SIZE to the outer class, or don't make it static. :-)
test.java:24: Interface Queue of inner class test.
QueueAr not found.
class QueueAr implements Queue
^
test.java:12: Class Queue not found in type
declaration.
private Queue postfix;
^You need to import the Queue class, whatever that is.
test.java:18: Class StackAr not found in type
declaration.
opStack = new StackAr();^
You need to import the StackAr class, whatever that is.