convert between integer and string

The problem is like this:

Data transfer via socket. The sending side convert integer into string and the receiving side convert string back to integer. An exception appears when the receiving side wants to convert a text content into an integer. The exception is:

java.lang.NumberFormatException: null

at java.lang.Integer.parseInt(Integer.java:382)

at java.lang.Integer.parseInt(Integer.java:463)

The way I convert the integer into String (in an xml element creation method) is:

type.appendChild( document.createTextNode(new Integer(msg.type).toString()));

The way I convert the xml element String value back to integer is:

msgObj.type = Integer.parseInt(data.item(0).getNodeValue());//data.item(0).getNodeValue() returns a String value.

The run time exception occurs when doing the converting back to the integer. What could it be wrong?

Thanks.

[917 byte] By [ilikeit888] at [2007-9-27 18:58:22]