The StAXSource/StAXResult Classes
The main visible difference between the XXXSource and XXXResult classes is their constructors. Their "engines," along with their individual particularities, are not visible. Theoretically, you can use all these classes in the same manner, but you must always instantiate them properly. For example, the StAXSource class provides two constructors:
-
public StAXSource(XMLStreamReader XMLsr): Creates a StAXSource based on the XMLStreamReader, XMLsr;.
-
public StAXSource(XMLEventReader XMLer)throws XMLStreamException: Creates a StAXSource based on the XMLEventReader, XMLer;
As you can see, you can use the first constructor with the Cursor API and the second constructor with the Event Iterator API. A good description of the XMLStreamReader and XMLEventReader interfaces can be found here.
To sustain these two constructors, the StAXSource class provides the following four methods:
-
public void setSystemId(String system_id): Specifies the system identifier.
-
public String getSystemId(): Obtains the system identifier.
-
public XMLStreamReader getXMLStreamReader(): Obtains the XMLStreamReader for the current StAXSource.
-
public XMLEventReader getXMLEventReader(): Obtains the XMLStreamReader for the current StAXSource.
The StAXResult class comes with the following two constructors:
-
public StAXResult(XMLStreamWriter XMLsw): Creates a StAXResult based on the
-
public StAXResult(XMLEventWriter XMLew): Create a StAXResult based on the XMLEventWriter, XMLew.
You probably notice that one constructor is for the Cursor API and one is for the Event Iterator API—exactly like in the case of StAXSource. A good description of the XMLStreamWriter and XMLEventWriter interfaces can be found here.
For sustain these two constructors the StAXResult class provide the following four methods:
-
public void setSystemId(String system_id): Specifies the system identifier.
-
public String getSystemId(): Obtains the system identifier.
-
public XMLStreamWriter getXMLStreamWriter(): Obtain the XMLStreamWriter for the current StAXResult.
-
public XMLEventWriter getXMLEventWriter(): Obtains the XMLEventWriter for the current StAXResult.
Performing an XSLT Transformation with TrAX
Before you can perform an XSLT/TrAX transformation with the StAXSource and StAXResult classes, it's helpful to be familiar with what's involved in an XSLT/TrAX transformation. Here's a brief introductionto an XSLT/TrAX transformation (the following steps do not depend on the XXXSource and XXXResult classes):
- Obtaining a
javax.xml.transform.TransformerFactory object: TransformerFactory is an abstract factory class that provides an XSLT processor (you can use the default processor or one like Saxon, Xalan, etc). Instantiate this class bycalling the newInstance method:
//get a TransformerFactory object
TransformerFactory transfFactory=TransformerFactory.newInstance();
To indicate that you're using a different XSLT processor than the default, set the javax.xml.transform.TransformerFactory system property:
//setting the javax.xml.transform.TransformerFactory system property for the
Saxon processor System.setProperty("javax.xml.transform.TransformerFactory",
"org.apache.xalan.processor.TransformerFactoryImpl");
//setting the javax.xml.transform.TransformerFactory system property for the
Xalan processor System.setProperty("javax.xml.transform.TransformerFactory",
"net.sf.saxon.TransformerFactoryImpl");
- Provide a
javax.xml.transform.Source object for the XSL stylesheet. First, decide what kind of source you will use and then instantiate the proper XXXSource class.
- Obtain a
javax.xml.transform.Transformer object by calling the newTransformer method. This object will transform the source-tree into result-tree.
public abstract Transformer newTransformer(Source source) throws
TransformerConfigurationException
Pass the Source of the XSL stylesheet (the source argument) to the newTransformer method.
- Indicate the XML document for transformation by creating another Source object. Depending on the source type, you must instantiate the proper
XXXSource class.
- Obtain a
javax.xml.transform.Result object. First, decide what kind of result you will use and then instantiate the proper XXXResult class.
- Begin the transformation by calling the
Transformer.transform method. This method retrieves the Source of the XML document you want to transform and the Result of that transformation:
public abstract void transform(Source XMLs, Result result)throws
TransformerException
New on the Java Boutique:
New Review:
Time Management Made Easy with the Quartz Enterprise Job Scheduler
Why not just use the Java timer API? This open source scheduling
API boasts simplicity, ease-of-integration, a well-rounded feature
set, and it's free!
New Applet:
Reverse Complement
Reverse Complement is a simple applet that converts DNA or RNA
sequences into three useful formats.
Elsewhere on internet.com:
WebDeveloper Java
Lots of Java information on webdeveloper.com
WDVL Java
Thorough Java resource at the Web Developer's Virtual Library.
ScriptSearch Java
Hundreds of free Java code files to download.
jGuru: Your View of the Java Universe
Customizable portal with online training, FAQs, regular news updates, and tutorials.
|
