Processing XML - Java - page 812

which doesn't actually indent but at least causes line breaks). Wrap the document in a
DomSource object, and the output stream in a StreamResult object. Pass the wrapped input
and output into the Transformer 's transform() method, and it will convert the in-memory
tree to text and write it to the given StreamResult .

For example, suppose you want to generate a poem in XML. Example 20-14 shows what
running the program and letting the XML appear on the standard output might look like.

Example 20-14. DocWrite.java
$ java xml . DocWriteDOM
Writing the tree now ...
<? xml version = "1.0" encoding = "UTF-8" ?>
< Poem >
< Stanza >
< Line > Once , upon a midnight dreary </ Line >
< Line > While I pondered , weak and weary </ Line >
</ Stanza >
</ Poem >
$

The code for this is fairly short; see Example 20-15 for the code using DOM. Code for using
JDOM is similar but used JDOM's own classes; see DocWriteJDOM.java in the javasrc pro-
ject.

Example 20-15. DocWriteDOM.java
public

public class class DocWriteDOM DocWriteDOM {

public public static static void void main ( String [] av ) throws throws Exception {

DocWriteDOM dw = new new DocWriteDOM ();

Document doc = dw . makeDoc ();

System . out . println ( "Writing the tree now..." );
Transformer tx = TransformerFactory . newInstance (). newTransformer ();
tx . setOutputProperty ( OutputKeys . INDENT , "yes" );
tx . transform ( new

new DOMSource ( doc ), new new StreamResult ( System . out ));

}

/** Generate the XML document */
protected

protected Document makeDoc () {
try

try {
DocumentBuilderFactory fact = DocumentBuilderFactory . newInstance ();
DocumentBuilder parser = fact . newDocumentBuilder ();
Document doc = parser . newDocument ();