java file execution 1

[yytan]

may i know how to exe follow java prog?

-- source code --

import java.util.Iterator;
import java.lang.reflect.Array;

public class ArrayIterator implements Iterator {
private final int size;
private int cursor;
private final Object array;
private ArrayIterator(Object array) {
this.array = array;
this.size = Array.getLength(array);
}
public static Iterator getInstance(Object obj) {
Class type = obj.getClass();
if (!type.isArray()) {
throw new IllegalArgumentException("Invalid type: " + type);
} else {
return new ArrayIterator(obj);
}
}
public void remove() {
throw new UnsupportedOperationException();
}
public boolean hasNext() {
return (cursor < size);
}
public Object next() {
return Array.get(array, cursor++);
}
public static void main(String args[]) {
loop(ArrayIterator.getInstance(args));
int intArray[] = {10, 20, 30, 40, 50};
loop(ArrayIterator.getInstance(intArray));
try {
loop(ArrayIterator.getInstance("Hello, World!"));
} catch (IllegalArgumentException e) {
System.err.println("Bad arg: " + e.getMessage());
}
}
private static void loop(Iterator iter) {
while (iter.hasNext()) {
System.out.println(iter.next());
}
System.out.println("-------");
}
}

 

[sedj]

java -cp . ArrayIterator

--------------------------------------------------
Free Database Connection Pooling Software

http://www.primrose.org.uk

 

[yytan]

dear sedj;

when java -cp . ArrayIterator

it shown

D:\>java ArrayIterator
-------
10
20
30
40
50
-------
Bad arg: Invalid type: class java.lang.String

rgd/ yoke yew

 

[sedj]

Well, yes - you have coded it to do that -

if (!type.isArray()) {
throw new IllegalArgumentException("Invalid type: " + type);
}

When you pass a String to it in this line :

loop(ArrayIterator.getInstance("Hello, World!"));


--------------------------------------------------
Free Database Connection Pooling Software

http://www.primrose.org.uk

 

[yytan]

ahh ok ok..

10s sedj

rgd/ yoke yew