 public boolean collectZips(XmlObject empDoc) {
// The query is designed to return results, so return
// true if it does.
boolean hasResults = false;
// The expression: Get the < zip > elements and return them as children
// of a new < zip-list > element.
String queryExpression =
"let $e := $this/xq:employees " +
"return " +
"< zip-list > " +
"{for $z in $e/xq:employee/xq:address/xq:zip " +
"return $z} " +
"< /zip-list >";
// Execute the query. Results will be copies of the XML queried against,
// stored as members of an XmlObject array.
XmlObject[] results =
empDoc.execQuery(m_namespaceDeclaration + queryExpression);
// Print the results.
if (results.length > 0)
{
hasResults = true;
System.out.println("The query results: \n");
System.out.println(results[0].toString() + "\n");
}
return hasResults;
}
Uses XQuery to retrieve work elements from the incoming XML, adding the
elements as children to a element.
This method demonstrates the following characteristics of the execQuery method:
- it supports XQuery.
- execQuery called from an XmlObject returns an array of XmlObject instances.
These are bound to copies of the received XML. |
public boolean updateWorkPhone(XmlObject empDoc) {
boolean hasResults = false;
// A cursor instance to query with.
XmlCursor empCursor = empDoc.newCursor();
// The expression: Get the < employee > elements with < state > elements whose
// value is "WA".
String queryExpression =
"for $e in $this/xq:employees/xq:employee " +
"let $s := $e/xq:address/xq:state " +
"where $s = 'WA' " +
"return $e//xq:phone[@location='work']";
// Execute the query. Results, if any, will be available at
// the position of the resultCursor in a new XML document.
XmlCursor resultCursor =
empCursor.execQuery(m_namespaceDeclaration + queryExpression);
System.out.println("The query results, < phone > element copies made " +
"from the received document: \n");
System.out.println(resultCursor.getObject().toString() + "\n");
// If there are results, the results will be children of the fragment root
// where the new cursor is positioned. This statement tests for children
// and moves the cursor if to the first if it exists.
if (resultCursor.toFirstChild())
{
hasResults = true;
// Use the cursor to loop through the results, printing each sibling
// < employee > element returned by the query.
int i = 0;
do
{
// Change the phone numbers.
XmlCursor editCursor = resultCursor.newCursor();
editCursor.toLastAttribute();
editCursor.toNextToken();
editCursor.removeXml();
editCursor.insertChars("(206)555-1234");
} while (resultCursor.toNextSibling());
resultCursor.toStartDoc();
System.out.println("The query results after changes: \n");
System.out.println(resultCursor.getObject().toString() + "\n");
System.out.println("The received document -- note that it is unchanged. " +
"Changes were made to the copy created by the execQuery method. \n");
System.out.println(empDoc + "\n");
}
return hasResults;
} Uses XQuery to retrieve work elements from the incoming XML, then
changes the number in the results.
This method demonstrates the following characteristics of the execQuery method:
- it supports XQuery.
- the XML it returns is a copy of the XML queried against; contrast this with
the selectPath method, which returns a portion of the original document.
Changes to returned XML do not impact the XML queried against.
- execQuery called from an XmlCursor returns a cursor positioned at
the STARTDOC token of a new XML fragment. Contrast this with the
XmlCursor.selectPath method, which stores results as "selections" in
the cursor used to execute the query. |
org.apache.xmlbeans.samples.xquery.ExecQuery