Pro XML Development with Java Technology 2006 phần 7 ppsx

210 CHAPTER 7 ■ BINDING WITH XMLBEANS

try { //Create a cursor

CatalogDocument catalogDocument = CatalogDocument.Factory

.parse(xmlFile);

XmlCursor cursor = catalogDocument.newCursor();

//Move cursor to start of root Element

cursor.toFirstContentToken();

//Move cursor to first child element

cursor.toFirstChild();

//Add an Element

cursor.beginElement("journal");

//Add an attribute

cursor.insertAttributeWithValue("publisher", "IBM developerWorks");

cursor.dispose();

//Output modified document

System.out.println(catalogDocument.toString());

} catch (IOException e) {

} catch (XmlException e) {

}

}

//Method to navigate an XML document

public void navigateXMLDocument(File xmlFile) {

try { //Create a CatalogDocument object and create a cursor

CatalogDocument catalogDocument = CatalogDocument.Factory

.parse(xmlFile);

XmlCursor cursor = catalogDocument.newCursor();

//Move cursor to start of root Element

cursor.toFirstContentToken();

//Move cursor to start of first child Element

cursor.toFirstChild();

//Move cursor to start of article element

cursor.toFirstChild();

//Move cursor to start of title element

cursor.toFirstChild();

System.out.println(cursor.getTextValue());

//Dispose cursor

cursor.dispose();

} catch (IOException e) {

} catch (XmlException e) {

}

}

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CHAPTER 7 ■ BINDING WITH XMLBEANS 211

public static void main(String[] args) {

XMLBeansCursor xmlBeansCursor = new XMLBeansCursor();

File xmlFile = new File("catalog.xml");

xmlBeansCursor.navigateXMLDocument(xmlFile);

xmlBeansCursor.addElement(xmlFile);

xmlBeansCursor.selectWithXPath(xmlFile);

xmlBeansCursor.selectWithXQuery(xmlFile);

}

}

Summary

XMLBeans is an XML-to-Java binding and runtime framework that is similar to JAXB. You can use

the binding framework to bind an XML Schema to Java types. XMLBeans offers complete support for

all XML Schema constructs. You can use a binding configuration file to customize XML Schema to

Java type bindings. You can use the runtime framework to unmarshal and marshal an XML docu￾ment to and from Java objects that are instances of bound Java types.

In addition to marshaling and unmarshaling an XML document, XMLBeans offers low-level

navigational support through the XmlCursor API. Using the XmlCursor API, you can position a

cursor at a specified location and modify the document content at that location. This API also provides

support for addressing document content with XPath and querying an XML document using the

XQuery language.

In our opinion, JAXB 2.0 should be the default choice for an XML Schema to Java types binding

framework, mainly because of the following reasons:

• It is part of the Java standards.

• It offers support for the bidirectional mapping between XML Schema content and Java types.

However, the following pragmatic reasons may indicate XMLBeans to be the more appropriate

choice:

• You are looking for full XML Schema support, but you are not ready to move to J2SE 5.0.

• During the marshaling process, you want low-level control over the XML markup contained

in the marshaled XML document.

• During the unmarshaling process, you want to use XPath to address specific nodes within the

XML document, or you want to use the XQuery language to query the content of an XML

document.

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