import com.saxonica.config.EnterpriseConfiguration;
import com.saxonica.pull.PullFromIterator;
import com.saxonica.pull.PullNamespaceReducer;
import com.saxonica.pull.PullTracer;
import com.saxonica.pull.TreeWalker;
import net.sf.saxon.Configuration;
import net.sf.saxon.TransformerFactoryImpl;
import net.sf.saxon.value.Whitespace;
import net.sf.saxon.event.PipelineConfiguration;
import net.sf.saxon.event.Receiver;
import net.sf.saxon.lib.SerializerFactory;
import net.sf.saxon.event.Sink;
import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.lib.Validation;
import net.sf.saxon.pull.*;
import net.sf.saxon.query.DynamicQueryContext;
import net.sf.saxon.query.StaticQueryContext;
import net.sf.saxon.query.XQueryExpression;
import net.sf.saxon.tree.tiny.TinyBuilder;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.tree.linked.LinkedTreeBuilder;
import javax.xml.transform.*;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import java.io.*;
import java.util.Properties;
/**
* This class contains some examples of how to use the Pull interfaces
* in Saxon.
*/
public class PullExamples {
private Configuration config;
/**
* Serialize a document that is supplied via the pull interface
*/
public void serialize(PullProvider in, OutputStream out) throws XPathException, IOException {
Properties props = new Properties();
props.setProperty(OutputKeys.METHOD, "xml");
props.setProperty(OutputKeys.INDENT, "yes");
SerializerFactory sf = config.getSerializerFactory();
Receiver receiver = sf.getReceiver(new StreamResult(out),
in.getPipelineConfiguration(),
props);
new PullPushCopier(in, receiver).copy();
}
/**
* Validate a document that is supplied via the pull interface
* (This requires the schema-aware version of Saxon)
*/
public void validate(PullProvider in) throws XPathException, IOException {
EnterpriseConfiguration config = new EnterpriseConfiguration();
PipelineConfiguration pipe = in.getPipelineConfiguration();
pipe.setConfiguration(config);
pipe.setSchemaURIResolver(config.getSchemaURIResolver());
Receiver sink = new Sink(pipe);
Receiver validator = config.getDocumentValidator(
sink, in.getSourceLocator().getSystemId(), Validation.STRICT, Whitespace.NONE, null, -1);
new PullPushCopier(in, validator).copy();
System.out.println("Done.");
}
/**
* Transform a document supplied via the pull interface
*/
public void transform(PullProvider in, File stylesheet, OutputStream out) throws TransformerException {
TransformerFactory factory = new TransformerFactoryImpl();
Templates templates = factory.newTemplates(new StreamSource(stylesheet));
Transformer transformer = templates.newTransformer();
transformer.transform(
new PullSource(in),
new StreamResult(out)
);
}
/**
* Run a query against input that is supplied using the pull interface
*/
public void query(PullProvider in, String query, OutputStream out) throws XPathException {
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery(query);
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
dynamicContext.setContextItem(config.buildDocument(new PullSource(in)));
Properties props = new Properties();
props.setProperty(OutputKeys.INDENT, "yes");
exp.run(dynamicContext, new StreamResult(out), props);
}
/**
* Build a Saxon "tiny" tree from input supplied via the pull interface
*/
public NodeInfo build(PullProvider in) throws XPathException {
TinyBuilder builder = new TinyBuilder(in.getPipelineConfiguration());
new PullPushCopier(in, builder).copy();
return builder.getCurrentRoot();
}
/**
* Build a Saxon "standard" tree from input supplied via the pull interface
*/
public NodeInfo buildStandardTree(PullProvider in) throws XPathException {
PipelineConfiguration pipe = in.getPipelineConfiguration();
LinkedTreeBuilder builder = new LinkedTreeBuilder(pipe);
builder.open();
new PullPushCopier(in, builder).copy();
builder.close();
return builder.getCurrentRoot();
}
/**
* Get a PullProvider based on a StAX Parser for a given input file
*/
public PullProvider getParser(File input) throws FileNotFoundException, XPathException {
StaxBridge parser = new StaxBridge();
parser.setInputStream(input.toURI().toString(), new FileInputStream(input));
parser.setPipelineConfiguration(config.makePipelineConfiguration());
// For diagnostics, confirm which XMLStreamReader implementation is being used
//System.err.println("StAX parser: " + parser.getXMLStreamReader().getClass().getName());
return parser;
}
/**
* Get a PullProvider based on a document or element node in a Saxon tree
*/
public PullProvider getTreeWalker(NodeInfo root) {
return TreeWalker.makeTreeWalker(root);
}
/**
* Run a query to produce a sequence of element nodes, and get a PullProvider over the results
* of the query
*/
public PullProvider pullQueryResults(NodeInfo source, String query) throws XPathException {
final StaticQueryContext sqc = config.newStaticQueryContext();
final XQueryExpression exp = sqc.compileQuery(query);
final DynamicQueryContext dynamicContext = new DynamicQueryContext(config);
dynamicContext.setContextItem(source);
PullProvider pull = new PullFromIterator(exp.iterator(dynamicContext));
pull = new PullNamespaceReducer(pull);
pull.setPipelineConfiguration(config.makePipelineConfiguration());
return pull;
}
/**
* Create a copy of a document, filtered to remove all elements named "PRICE",
* together with their contents
*/
public void removePriceElements(PullProvider in, OutputStream out) throws IOException, XPathException {
final int priceElement = config.getNamePool().allocate("", "", "PRICE");
PullFilter filter = new PullFilter(in) {
public int next() throws XPathException {
currentEvent = super.next();
if (currentEvent == START_ELEMENT && getFingerprint() == priceElement) {
super.skipToMatchingEnd();
currentEvent = next();
}
return currentEvent;
}
};
serialize(filter, out);
}
/**
* Get the average price of books, by scanning a document and taking the average of the
* values of the PRICE elements
*/
public void displayAveragePrice(PullProvider in, OutputStream out) throws IOException, XPathException {
final int priceElement = config.getNamePool().allocate("", "", "PRICE");
double total = 0;
int count = 0;
while (true) {
int event = in.next();
if (event == PullProvider.END_OF_INPUT) {
break;
}
if (event == PullProvider.START_ELEMENT && in.getFingerprint() == priceElement) {
double value = config.getConversionRules().getStringToDoubleConverter().stringToNumber(in.getStringValue());
total += value;
count++;
}
}
double average = (count==0 ? Double.NaN : total/count);
String result = "<result>" + average + "</result>";
OutputStreamWriter writer = new OutputStreamWriter(out);
writer.write(result);
writer.flush();
}
/**
* Main program. Arguments:
* <ol>
* <li>Select examples. Each example is identified by a single letter. Use # to run all examples.
* <li>-s Source document</li>
* <li>-o Output file</li>
* <li>-xsl Stylesheet</li>
* <li>-q Query
* </ol>
*/
public static void main(String[] args) throws Exception {
String examples;
if (args.length < 1 || args[0].equals("#")) {
examples = "abcdefghijklmnopqrstuvwxyz";
} else {
examples = args[0];
}
File input = null;
OutputStream output = null;
String query = null;
File stylesheet = null;
for (int i=1; i<args.length; i++) {
if (args[i].equals("-s")) {
input = new File(args[++i]);
} else if (args[i].equals("-o")) {
output = new FileOutputStream(new File(args[++i]));
} else if (args[i].equals("-q")) {
query = readFile(new File(args[++i]));
} else if (args[i].equals("-xsl")) {
stylesheet = new File(args[++i]);
} else {
System.err.println("Unknown argument " + args[i]);
}
}
if (input==null) {
input = new File("data/books.xml");
}
if (output==null) {
output = System.out;
}
if (stylesheet==null) {
stylesheet = new File("styles/books.xsl");
}
if (query==null) {
query = readFile(new File("query/books.xq"));
}
PullExamples o = new PullExamples();
Configuration config = Configuration.newConfiguration();
config.setLazyConstructionMode(true);
//config.setLineNumbering(true);
o.config = config;
PipelineConfiguration pipe = config.makePipelineConfiguration();
for (int i=0; i<examples.length(); i++) {
char ex = examples.charAt(i);
switch (ex) {
case 'a': {
System.out.println("\n\n=== Serialize the input to the output ===\n");
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.serialize(p, output);
break;
}
case 'b': {
System.out.println("\n\n=== Validate the input ===\n");
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.validate(p);
break;
}
case 'c': {
System.out.println("\n\n=== Transform the input to the output ===\n");
if (stylesheet == null) {
System.err.println("** No stylesheet supplied");
break;
}
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.transform(p, stylesheet, output);
break;
}
case 'd': {
System.out.println("\n\n=== Run XQuery against the input ===\n");
// Needs Saxon Professional Edition
if ("HE".equals(config.getEditionCode())) {
System.err.println("Pull-mode query requires Saxon-PE");
} else {
if (query == null) {
query = "<result>{.}</result>";
}
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.query(p, query, output);
break;
}
}
case 'e': {
System.out.println("\n\n=== Remove PRICE elements from the input ===\n");
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.removePriceElements(p, output);
break;
}
case 'f': {
System.out.println("\n\n=== Compute average of PRICE elements in the input ===\n");
PullProvider p = o.getParser(input);
p.setPipelineConfiguration(pipe);
o.displayAveragePrice(p, output);
break;
}
case 'g': {
System.out.println("\n\n=== Obtain query results using a pull iterator ===\n");
NodeInfo node = config.buildDocument(new StreamSource(input));
PullProvider p = o.pullQueryResults(node,
"declare function local:f() {"+
"for $var1 in (<abc/>, <def/>)"+
"return <e xmlns:x='x1'><f xmlns:y='y1' xmlns:x='x2'>xyz</f></e>};"+
"local:f()"
);
o.serialize(new PullTracer(p), output);
break;
}
case 'h': {
System.out.println("\n\n=== Obtain query results using a pull iterator on a 'standard' tree ===\n");
PullProvider p1 = o.getParser(input);
p1.setPipelineConfiguration(pipe);
NodeInfo node = o.buildStandardTree(p1);
PullProvider p2 = o.pullQueryResults(node,
"//CATEGORIES"
);
o.serialize(p2, output);
}
}
}
}
/**
* Read the contents of a file into a string
*/
public static String readFile(File file) throws IOException {
Reader reader = new FileReader(file);
char[] buffer = new char[4096];
StringBuffer sb = new StringBuffer(4096);
while (true) {
int n = reader.read(buffer);
if (n>0) {
sb.append(buffer, 0, n);
} else {
break;
}
}
return sb.toString();
}
}
//
// 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.
//