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Replace XMLReaderFactory with SAXParserFactory

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XMLReaderFactory has been marked as deprecated and without additional
configuration, and it's slower than SAXParserFactory.

Previously `XMLReaderFactory.createXMLReader()` is called upon every
request. This is an anti-pattern as mentioned in [1] and it can be very
slow since it loads the jar service file unless a parser has been
pre-assigned [2] (e.g. by setting org.xml.sax.driver).

SAXParserFactory uses a FactoryFinder [3] instead, which takes advantage
of a thread-local cache provided by ServiceLoader. Developers can still
pre-assign a factory by setting javax.xml.parsers.SAXParserFactory to
make it faster.

[1] https://bugs.openjdk.java.net/browse/JDK-6925410
[2] c8add223a1/src/java.xml/share/classes/org/xml/sax/helpers/XMLReaderFactory.java (L144-L148)
[3] 66c653c561/src/java.xml/share/classes/javax/xml/parsers/SAXParserFactory.java (L181-L185)

See gh-27239
This commit is contained in:
Frederick Zhang
2021-08-04 17:15:18 +10:00
committed by Stephane Nicoll
parent 32359c52b4
commit baed0785fd
8 changed files with 71 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
spring-oxm/src/main/java/org/springframework/oxm/jaxb/Jaxb2Marshaller.java
View File

@@ -42,6 +42,9 @@ import javax.xml.XMLConstants;
import javax.xml.datatype.Duration;
import javax.xml.datatype.XMLGregorianCalendar;
import javax.xml.namespace.QName;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamReader;
@@ -575,8 +578,7 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
}
}
@SuppressWarnings("deprecation")
private Schema loadSchema(Resource[] resources, String schemaLanguage) throws IOException, SAXException {
private Schema loadSchema(Resource[] resources, String schemaLanguage) throws IOException, SAXException, ParserConfigurationException {
if (logger.isDebugEnabled()) {
logger.debug("Setting validation schema to " +
StringUtils.arrayToCommaDelimitedString(this.schemaResources));
@@ -584,8 +586,11 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
Assert.notEmpty(resources, "No resources given");
Assert.hasLength(schemaLanguage, "No schema language provided");
Source[] schemaSources = new Source[resources.length];
XMLReader xmlReader = org.xml.sax.helpers.XMLReaderFactory.createXMLReader();
xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
saxParserFactory.setNamespaceAware(true);
saxParserFactory.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
SAXParser saxParser = saxParserFactory.newSAXParser();
XMLReader xmlReader = saxParser.getXMLReader();
for (int i = 0; i < resources.length; i++) {
Resource resource = resources[i];
Assert.isTrue(resource != null && resource.exists(), () -> "Resource does not exist: " + resource);
@@ -854,7 +859,6 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
}
}
@SuppressWarnings("deprecation")
private Source processSource(Source source) {
if (StaxUtils.isStaxSource(source) || source instanceof DOMSource) {
return source;
@@ -881,17 +885,20 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
try {
if (xmlReader == null) {
xmlReader = org.xml.sax.helpers.XMLReaderFactory.createXMLReader();
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
saxParserFactory.setNamespaceAware(true);
saxParserFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", !isSupportDtd());
String name = "http://xml.org/sax/features/external-general-entities";
saxParserFactory.setFeature(name, isProcessExternalEntities());
SAXParser saxParser = saxParserFactory.newSAXParser();
xmlReader = saxParser.getXMLReader();
}
xmlReader.setFeature("http://apache.org/xml/features/disallow-doctype-decl", !isSupportDtd());
String name = "http://xml.org/sax/features/external-general-entities";
xmlReader.setFeature(name, isProcessExternalEntities());
if (!isProcessExternalEntities()) {
xmlReader.setEntityResolver(NO_OP_ENTITY_RESOLVER);
}
return new SAXSource(xmlReader, inputSource);
}
catch (SAXException ex) {
catch (SAXException | ParserConfigurationException ex) {
logger.info("Processing of external entities could not be disabled", ex);
return source;
}

17
spring-oxm/src/main/java/org/springframework/oxm/support/AbstractMarshaller.java
View File

@@ -26,6 +26,8 @@ import java.io.Writer;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamReader;
@@ -188,12 +190,15 @@ public abstract class AbstractMarshaller implements Marshaller, Unmarshaller {
* Create an {@code XMLReader} that this marshaller will when passed an empty {@code SAXSource}.
* @return the XMLReader
* @throws SAXException if thrown by JAXP methods
* @throws ParserConfigurationException if thrown by JAXP methods
*/
@SuppressWarnings("deprecation")
protected XMLReader createXmlReader() throws SAXException {
XMLReader xmlReader = org.xml.sax.helpers.XMLReaderFactory.createXMLReader();
xmlReader.setFeature("http://apache.org/xml/features/disallow-doctype-decl", !isSupportDtd());
xmlReader.setFeature("http://xml.org/sax/features/external-general-entities", isProcessExternalEntities());
protected XMLReader createXmlReader() throws SAXException, ParserConfigurationException {
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
saxParserFactory.setNamespaceAware(true);
saxParserFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", !isSupportDtd());
saxParserFactory.setFeature("http://xml.org/sax/features/external-general-entities", isProcessExternalEntities());
SAXParser saxParser = saxParserFactory.newSAXParser();
XMLReader xmlReader = saxParser.getXMLReader();
if (!isProcessExternalEntities()) {
xmlReader.setEntityResolver(NO_OP_ENTITY_RESOLVER);
}
@@ -431,7 +436,7 @@ public abstract class AbstractMarshaller implements Marshaller, Unmarshaller {
try {
saxSource.setXMLReader(createXmlReader());
}
catch (SAXException ex) {
catch (SAXException | ParserConfigurationException ex) {
throw new UnmarshallingFailureException("Could not create XMLReader for SAXSource", ex);
}
}

8
spring-oxm/src/test/java/org/springframework/oxm/AbstractUnmarshallerTests.java
View File

@@ -22,6 +22,8 @@ import java.io.StringReader;
import javax.xml.namespace.QName;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;
@@ -98,9 +100,11 @@ public abstract class AbstractUnmarshallerTests<U extends Unmarshaller> {
}
@Test
@SuppressWarnings("deprecation") // on JDK 9
public void unmarshalSAXSource() throws Exception {
XMLReader reader = org.xml.sax.helpers.XMLReaderFactory.createXMLReader();
SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
saxParserFactory.setNamespaceAware(true);
SAXParser saxParser = saxParserFactory.newSAXParser();
XMLReader reader = saxParser.getXMLReader();
SAXSource source = new SAXSource(reader, new InputSource(new StringReader(INPUT_STRING)));
Object flights = unmarshaller.unmarshal(source);
testFlights(flights);