Passing integer array from javascript to java

Hi Everyone,

I am having trouble passing an array between javascript and java.I am using DWR.

Demo.getData(userId,f1,f2,f3,CreateTable);

Demo is the java class I need to access and CreateTable is the fuction I need to pass my javascript arrays to.

f1,f2,f3 are my javascript arrays.

in Demo.java CreateTable is declared as :

public List CreateTable(int userId,int[] f1,int[] f2,int[] f3)

I need to pass the arrays of f1,f2 and f3 as Integer[] objects;
This is how I am trying to this:

Integer[] intObj = null;

if(f1!=null){
intObj = new Integer[f1.length];
for(int a=0;a<f1.length;a++){
intObj[a] = new Integer(filter[a]);
}
}

I have to then pass this to a hashmap:

HashMap<String,Integer[]> filters = new HashMap<String,Integer[]>();
filters.put("tagIds", intObj);

I get a java.lang.NullPointerException

However this works:
Integer[] tags = new Integer[]{1,2,3,4};
filters.put("tagIds",tags);

I am sure that the javascript array is being correctly passed to CreateTable()

Can some one point out what I am doing wrong?

Thanks,
Lavanya

It turns out my problem was not with passing arrays between javascript and java.

My objective was to convert int[]f1 to Integer[] f1 and pass this to another function.

It was possible that in some cases int[] f1 would be empty,
so I would directly pass 'null' the function.(intObj=null)

However the function I was calling did not know how to handle 'null'.So, now whenever int[] f1 is empty I pass:
Integer[] intObj = new Integer[]{}

So I guess the whole problem boils down to the difference between:
Integer[] intObj = new Integer[]{}
and
Integer[] intObj = null