The easiest most and most efficient way to update XML documents is to use non-extractive parsers (such as VTD-XML) because they support incremental content update. Suppose you have the following XML document, named test.xml. Below is a snippet that inserts two attribute name/value pairs into an XML document.

  <tag> hello world 

Now, here’s the Java code for doing the attribute insertion:

public class simpleApp2 {   public static void main(String[] s) throws Exception {      VTDGen vg = new VTDGen();      XMLModifier xm = new XMLModifier();      if (vg.parseFile("test.xml", false)){             VTDNav vn = vg.getNav();             xm.bind(vn);             xm.insertAttribute(" attr1='val1" attr2='val2'");             xm.output("new.xml");     }  }   }

The output, named new.xml, is shown below:

  hello world