Java Reference
In-Depth Information
The noargument
newTransformer()
method copies source input to the destina-
tionwithoutmakinganychanges.Thiskindoftransformationisknownasthe
identity
transformation
.
To change input, you need to specify a stylesheet, and you accomplish this task by
callingthefactory's
Transformer newTransformer(Source source)
meth-
od,wherethe
javax.xml.transform.Source
interfacedescribesasourceforthe
stylesheet. The following example demonstrates this task:
Transformer t = tf.newTransformer(new StreamSource(new
FileReader("recipe.xsl")));
This example creates a transformer that obtains a stylesheet from a file named
re-
cipe.xsl
via a
javax.xml.transform.stream.StreamSource
instance
connectedtoafilereader.Itiscustomarytousethe
.xsl
or
.xslt
extensiontoidenti-
fy XSLT stylesheet files.
The
newTransformer()
methodsthrow
TransformerConfigurationEx-
ception
whentheycannotreturna
Transformer
instancethatcorrespondstothe
factory configuration.
After obtaining a
Transformer
instance, you can call its
void setOut-
putProperty(String name, String value)
method to influence a trans-
formation. The
javax.xml.transform.OutputKeys
class declares constants
forfrequentlyusedkeys.Forexample,
OutputKeys.METHOD
isthekeyforspecify-
ingthemethodforoutputtingtheresulttree(asXML,HTML,plaintext,orsomething
else).
Tip
To set multiple properties in a single method call, create a
java.util.Properties
object and pass this object as an argument to
Trans-
former
's
void setOutputProperties(Properties prop)
method.
Properties set by
setOutputProperty()
and
setOutputProperties()
override the stylesheet's
xsl:output
instruction settings.
Before you can perform a transformation, you need to obtain instances of classes
thatimplementthe
Source
and
javax.xml.transform.Result
interfaces.You
then pass these instances to
Transformer
's
void transform(Source xm-
lSource, Result outputTarget)
method, which throws an instance of the
javax.xml.transform.TransformerException
class when a problem
arises during the transformation.
Thefollowingexampleshowsyouhowtoobtainasourceandaresult,andperform
the transformation:
