<?xml version="1.0" encoding="UTF-8"?>
<Customers>
<customer>
<id>3</id>
<gender>female</gender>
<firstname>Jessica</firstname>
<lastname>Lim</lastname>
<phoneNumber>1234567</phoneNumber>
<address>
<primaryAddress>
<postalCode>350106</postalCode>
<addressLine1>#25-1</addressLine1>
<addressLine2>SHINSAYAMA 2-CHOME</addressLine2>
</primaryAddress>
<billingAddress>
<receiver>Ms Danielle</receiver>
<postalCode>350107</postalCode>
<addressLine1>#167</addressLine1>
<addressLine2>NORTH TOWER HARBOUR CITY</addressLine2>
</billingAddress>
</address>
</customer>
</Customers>

public void updateCustomer(int id,String lastname) {
try {
File xmlFile = new File(filename);
CustomersDocument doc = CustomersDocument.Factory.parse(xmlFile);
CustomerType[] customers = doc.getCustomers().getCustomerArray();

for (int i = 0; i < customers.length; i ) {
CustomerType customer = customers[i];
if(customer.getId()==id){
customer.setLastname(lastname);
break;
}
}
doc.save(xmlFile);
} catch (Exception ex) {
ex.printStackTrace();
}
}

main method:

public static void main(String[] args) {
String filename = "F://JavaTest//Eclipse//XMLBean//xml//customers_new.xml";

CustomerXMLBean customerXMLBean = new CustomerXMLBean(filename);

customerXMLBean.updateCustomer(3,"last");
}