import net.sf.saxon.Configuration;
import net.sf.saxon.Controller;
import net.sf.saxon.instruct.UserFunction;
import net.sf.saxon.om.*;
import net.sf.saxon.query.DynamicQueryContext;
import net.sf.saxon.query.QueryResult;
import net.sf.saxon.query.StaticQueryContext;
import net.sf.saxon.query.XQueryExpression;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.Int64Value;
import net.sf.saxon.value.Value;
import net.sf.saxon.xpath.XPathEvaluator;
import javax.xml.transform.*;
import javax.xml.transform.dom.DOMResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.Properties;
/**
* Some examples to show how the Saxon XQuery API should be used
*/
public class QueryAPIExamples {
/**
* Class is not instantiated, so give it a private constructor
*/
private QueryAPIExamples() {
}
/**
* Method main
* @param argv Command line arguments
* <p>Format: QueryAPIExamples [testname]</p>
* <p>where testname is one of the tests (for their names, see the source code)</p>
*/
public static void main(String argv[]) {
String test = "all";
if (argv.length > 0) {
test = argv[0];
}
if (test.equals("all") || test.equals("toStreamResult")) {
System.out.println("\n\n==== toStreamResult ====");
try {
exampleToStreamResult();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toSingleton")) {
System.out.println("\n\n==== toSingleton ====");
try {
exampleToSingleton();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toDOM")) {
System.out.println("\n\n==== toDOM ====");
try {
exampleToDOM();
} catch (Exception ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toSequence")) {
System.out.println("\n\n==== toSequence ====");
try {
exampleToSequence();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toSerializedSequence")) {
System.out.println("\n\n==== toSerializedSequence ====");
try {
exampleToSerializedSequence();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toWrappedSequence")) {
System.out.println("\n\n==== toWrappedSequence ====");
try {
exampleToWrappedSequence();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("toHTMLFile")) {
System.out.println("\n\n==== toHTMLFile ====");
try {
exampleToHTMLFile();
} catch (XPathException ex) {
handleException(ex);
} catch (IOException ex) {
System.err.println("Problem reading/writing files. Check that the current directory is the 'samples' directory");
handleException(ex);
}
}
if (test.equals("all") || test.equals("withParam")) {
System.out.println("\n\n==== withParam ====");
try {
exampleWithParam();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("pipeline")) {
System.out.println("\n\n==== pipeline ====");
try {
examplePipeline();
} catch (XPathException ex) {
handleException(ex);
}
}
if (test.equals("all") || test.equals("directFunction")) {
System.out.println("\n\n==== directFunction ====");
try {
exampleDirectFunction();
} catch (XPathException ex) {
handleException(ex);
}
}
}
/**
* Show a query producing a document as its result and serializing this
* directly to System.out
*/
public static void exampleToStreamResult() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("<a b='c'>{5+2}</a>");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final Properties props = new Properties();
props.setProperty(OutputKeys.METHOD, "xml");
props.setProperty(OutputKeys.INDENT, "yes");
exp.run(dynamicContext, new StreamResult(System.out), props);
}
/**
* Show a query producing a single atomic value as its result and returning the value
* to the Java application
*/
public static void exampleToSingleton() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("avg(for $i in 1 to 10 return $i*$i)");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final BigDecimal result = (BigDecimal)exp.evaluateSingle(dynamicContext);
System.out.println(result);
}
/**
* Show a query producing a DOM as its output. The DOM is then serialized using
* an identity transform
*/
public static void exampleToDOM() throws TransformerException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("<a xmlns='http://a/uri' xmlns:a='another.uri'>text</a>");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
DOMResult result = new DOMResult();
exp.run(dynamicContext, result, new Properties());
// now serialize the DOM
Transformer identity = TransformerFactory.newInstance().newTransformer();
identity.transform(new DOMSource(result.getNode()), new StreamResult(System.out));
}
/**
* Show a query producing a sequence as its result and returning the sequence
* to the Java application in the form of an iterator. For each item in the
* result, its string value is output.
*/
public static void exampleToSequence() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("for $i in 1 to 10 return ($i * $i)");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final SequenceIterator iter = exp.iterator(dynamicContext);
while (true) {
Item item = iter.next();
if (item == null) {
break;
}
System.out.println(item.getStringValue());
}
}
/**
* Show a query producing a sequence as its result and returning the sequence
* to the Java application in the form of an iterator. The sequence is treated
* as if it were the content of a document{...} constructor. Note that it must
* not contain free-standing attribute nodes.
*/
public static void exampleToSerializedSequence() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("<doc><chap><a>3</a></chap></doc>//a, <b>4</b>, 19");
Properties props = new Properties();
props.setProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final SequenceIterator iter = exp.iterator(dynamicContext);
QueryResult.serializeSequence(iter, config, System.out, props);
}
/**
* Show a query producing a sequence as its result and returning the sequence
* to the Java application in the form of an iterator. The sequence is then
* output by wrapping the items in a document, with wrapping elements indicating
* the type of each item, and serializing the resulting document.
*/
public static void exampleToWrappedSequence() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("<doc><chap><a>3</a></chap></doc>//a, <b>4</b>, attribute c {5}, 19");
Properties props = new Properties();
props.setProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
props.setProperty(OutputKeys.INDENT, "yes");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
final SequenceIterator iter = exp.iterator(dynamicContext);
final DocumentInfo doc = QueryResult.wrap(iter, config);
QueryResult.serialize(doc, new StreamResult(System.out), props);
}
/**
* Show how to run a query that is read from a file and that serializes its output
* as HTML to another file. The input to the query (the initial value of the context
* node) is supplied as the content of another file.
*/
public static void exampleToHTMLFile() throws XPathException, IOException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery(new FileReader("query/books-to-html.xq"));
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
dynamicContext.setContextItem(config.buildDocument(new StreamSource("data/books.xml")));
final Properties props = new Properties();
props.setProperty(OutputKeys.METHOD, "html");
props.setProperty(OutputKeys.DOCTYPE_PUBLIC, "-//W3C//DTD HTML 4.01 Transitional//EN");
exp.run(dynamicContext, new StreamResult(new File("booklist.html")), props);
}
/**
* Show a query that takes a parameter (external variable) as input.
* The query produces a single atomic value as its result and returns the value
* to the Java application. For the types of value that may be returned, and
* their mapping to XPath data types, see {@link XPathEvaluator#evaluate}
*/
public static void exampleWithParam() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery("declare variable $in as xs:integer external;" +
"$in * $in");
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
dynamicContext.setParameter("in", new Long(17));
final Long result = (Long)exp.evaluateSingle(dynamicContext);
System.out.println("17 * 17 = " + result);
}
/**
* Show how to run two queries in tandem. The second query is applied to the
* results of the first.
*/
public static void examplePipeline() throws XPathException {
final Configuration config = new Configuration();
// Compile the first query
final StaticQueryContext sqc1 = config.newStaticQueryContext();
final XQueryExpression exp1 = sqc1.compileQuery("declare variable $in as xs:integer external;" +
"document{ <a>{$in * $in}</a> }");
// Compile the second query (each query should have its own static context)
final StaticQueryContext sqc2 = config.newStaticQueryContext();
final XQueryExpression exp2 = sqc2.compileQuery("/a + 5");
// Run the first query
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
dynamicContext.setParameter("in", new Long(3));
final NodeInfo doc = (NodeInfo)exp1.evaluateSingle(dynamicContext);
// Run the second query
dynamicContext.clearParameters();
dynamicContext.setContextItem(doc);
final Object result = exp2.evaluateSingle(dynamicContext);
System.out.println("3*3 + 5 = " + result);
// The result is actually a java.lang.Double
}
/**
* Show a direct call from the Java application to a function defined in the
* Query. This is a very efficient way of invoking a query, but it does minimal
* checking of the supplied arguments
*/
public static void exampleDirectFunction() throws XPathException {
final Configuration config = new Configuration();
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp1 = sqc.compileQuery("declare namespace f='f.ns';" +
"declare function f:t1($v1 as xs:integer, $v2 as xs:untypedAtomic*) { " +
" $v1 div $v2" +
"};" +
"10");
final UserFunction fn1 = exp1.getStaticContext().getUserDefinedFunction("f.ns", "t1", 2);
if (fn1 == null) {
throw new IllegalStateException("Function f:t1() not found");
}
final Controller controller = exp1.newController();
final Value[] arglist = new Value[2];
arglist[0] = new Int64Value(10);
for (int i = 3; i < 10; i++) {
arglist[1] = new Int64Value(i);
final ValueRepresentation result = fn1.call(arglist, controller);
System.out.println(arglist[0] + " div " + arglist[1] + " = " + result);
}
}
/**
* Handle an exception thrown while running one of the examples
*
* @param ex the exception
*/
private static void handleException(Exception ex) {
System.out.println("EXCEPTION: " + ex);
ex.printStackTrace();
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");
// you may not use this file except in compliance with the License. You may obtain a copy of the
// License at http://www.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay.
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//