Module java.xml

module java.xml
Defines the Java API for XML Processing (JAXP), the Streaming API for XML (StAX), the Simple API for XML (SAX), and the W3C Document Object Model (DOM) API.

JAXP Lookup Mechanism

JAXP defines an ordered lookup procedure to determine the implementation class to load for the JAXP factories. Factories that support the mechanism are listed in the table below along with the method, System Property name, Configuration File, and System Default method to be used in the procedure.
JAXP Factories
Factory Method System Property Name Configuration File System Default
DatatypeFactory newInstance() javax.xml.datatype.DatatypeFactory jaxp.properties newDefaultInstance()
DocumentBuilderFactory newInstance() javax.xml.parsers.DocumentBuilderFactory jaxp.properties newDefaultInstance()
SAXParserFactory newInstance() javax.xml.parsers.SAXParserFactory jaxp.properties newDefaultInstance()
XMLEventFactory newFactory() javax.xml.stream.XMLEventFactory stax.properties and then jaxp.properties newDefaultFactory()
XMLInputFactory newFactory() javax.xml.stream.XMLInputFactory stax.properties and then jaxp.properties newDefaultFactory()
XMLOutputFactory newFactory() javax.xml.stream.XMLOutputFactory stax.properties and then jaxp.properties newDefaultFactory()
TransformerFactory newInstance() javax.xml.transform.TransformerFactory jaxp.properties newDefaultInstance()
SchemaFactory newInstance(schemaLanguage) javax.xml.validation.SchemaFactory:schemaLanguage[1] jaxp.properties newDefaultInstance()
XPathFactory newInstance(uri) DEFAULT_PROPERTY_NAME + ":uri"[2] jaxp.properties newDefaultInstance()
[1] where schemaLanguage is the parameter to the newInstance(schemaLanguage) method.

[2] where uri is the parameter to the newInstance(uri) method.

jaxp.properties

jaxp.properties is a configuration file in standard Properties format and typically located in the conf directory of the Java installation. It contains the fully qualified name of the implementation class with the key being the system property name defined in the table above.

The jaxp.properties file is read only once by the implementation and the values are then cached for future use. If the file does not exist when the first attempt is made to read from it, no further attempts are made to check for its existence. It is not possible to change the value of any property after it has been read for the first time.

stax.properties

stax.properties is a configuration file that functions the same as jaxp.properties except that it is only used by StAX factory lookup.

Lookup Procedure

The JAXP Factories follow the procedure described below in order to locate and load the implementation class:
Implementation Note:

Implementation Specific Features and Properties

In addition to the standard features and properties described within the public APIs of this module, the JDK implementation supports a further number of implementation specific features and properties. This section describes the naming convention, System Properties, jaxp.properties, scope and order, and processors to which a property applies. A table listing the implementation specific features and properties which the implementation currently supports can be found at the end of this note.

Naming Convention

The names of the features and properties are fully qualified, composed of a prefix and name.

Prefix

The prefix for JDK features and properties, as well as their corresponding System Properties if any, is defined as: 
     jdk.xml.

Name

A name may consist of one or multiple words that are case-sensitive. All letters of the first word are in lowercase, while the first letter of each subsequent word is capitalized.

An example of a property that indicates whether an XML document is standalone would thus have a format: 

     jdk.xml.isStandalone
and a corresponding System Property: 
     jdk.xml.isStandalone

System Properties

A property may have a corresponding System Property with the same name. A System Property should be set prior to the creation of a processor and may be cleared afterwards.

jaxp.properties

A system property can be specified in the jaxp.properties file to set the behavior for all invocations of the JDK. The format is system-property-name=value. For example: 
     jdk.xml.isStandalone=true

Scope and Order

The XMLConstants.FEATURE_SECURE_PROCESSING feature (hereafter referred to as secure processing) is required for XML processors including DOM, SAX, Schema Validation, XSLT, and XPath. When secure processing is set to true, security related features and properties, such as those flagged as "security: yes" (hereafter referred to as security properties) in table Implementation Specific Features and Properties, are enforced. Such enforcement includes setting security properties and features to more restrictive values and limits as shown in "Value"'s subcolumn "Enforced" in the tables. When secure processing is set to false, however, the property values will not be affected.

When the Java Security Manager is present, secure processing is set to true and can not be turned off. The security properties are therefore enforced.

Properties specified in the jaxp.properties file affect all invocations of the JDK, and will override their default values, or those that may have been set by secure processing.

System properties, when set, affect the invocation of the JDK and override the default settings or those that may have been set in jaxp.properties or by secure processing.

JAXP properties specified through JAXP factories or processors (e.g. SAXParser) take preference over system properties, the jaxp.properties file, as well as secure processing.

Processor Support

Features and properties may be supported by one or more processors. The following table lists the processors by IDs that can be used for reference.
Processors
ID Name How to set the property How to set the feature
DOM DOM Parser DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setAttribute(name, value); 		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setFeature(name, value);
SAX SAX Parser SAXParserFactory spf = SAXParserFactory.newInstance();
SAXParser parser = spf.newSAXParser();
parser.setProperty(name, value); 		SAXParserFactory spf = SAXParserFactory.newInstance();
spf.setFeature(name, value);
StAX StAX Parser XMLInputFactory xif = XMLInputFactory.newInstance();
xif.setProperty(name, value); 		XMLInputFactory xif = XMLInputFactory.newInstance();
xif.setProperty(name, value);
Validation XML Validation API SchemaFactory schemaFactory = SchemaFactory.newInstance(schemaLanguage);
schemaFactory.setProperty(name, value); 		SchemaFactory schemaFactory = SchemaFactory.newInstance(schemaLanguage);
schemaFactory.setFeature(name, value);
Transform XML Transform API TransformerFactory factory = TransformerFactory.newInstance();
factory.setAttribute(name, value); 		TransformerFactory factory = TransformerFactory.newInstance();
factory.setFeature(name, value);
XSLTC Serializer XSLTC Serializer Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(name, value);
DOMLS DOM Load and Save LSSerializer serializer = domImplementation.createLSSerializer();
serializer.getDomConfig().setParameter(name, value);
XPath XPath XPathFactory factory = XPathFactory.newInstance();
factory.setFeature(name, value);

Implementation Specific Features and Properties

The Implementation Specific Features and Properties reflect JDK's choice to manage the limitations on resources while complying with the API specification, or allow applications to alter behaviors beyond those required by the standards.

The table below lists the Implementation Specific Properties currently supported by the JDK. More properties may be added in the future if necessary.

Implementation Specific Properties
Full Name (prefix + name) [1] Description System Property [2] jaxp.properties [2] Value [3] Security [4] Supported Processor [5] Since [6]
Type Value Default Enforced
jdk.xml.entityExpansionLimit Limits the number of entity expansions. yes yes Integer A positive integer. A value less than or equal to 0 indicates no limit. If the value is not an integer, a NumberFormatException is thrown. 64000 64000 Yes DOM
SAX
StAX
Validation
Transform 		8
jdk.xml.elementAttributeLimit Limits the number of attributes an element can have. 10000 10000
jdk.xml.maxOccurLimit Limits the number of content model nodes that may be created when building a grammar for a W3C XML Schema that contains maxOccurs attributes with values other than "unbounded". 5000 5000
jdk.xml.totalEntitySizeLimit Limits the total size of all entities that include general and parameter entities. The size is calculated as an aggregation of all entities. 5x10^7 5x10^7
jdk.xml.maxGeneralEntitySizeLimit Limits the maximum size of any general entities. 0 0
jdk.xml.maxParameterEntitySizeLimit Limits the maximum size of any parameter entities, including the result of nesting multiple parameter entities. 10^6 10^6
jdk.xml.entityReplacementLimit Limits the total number of nodes in all entity references. 3x10^6 3x10^6
jdk.xml.maxElementDepth Limits the maximum element depth. 0 0
jdk.xml.maxXMLNameLimit Limits the maximum size of XML names, including element name, attribute name and namespace prefix and URI. 1000 1000
jdk.xml.isStandalone Indicates that the serializer should treat the output as a standalone document. The property can be used to ensure a newline is written after the XML declaration. Unlike the property xml-declaration, this property does not have an effect on whether an XML declaration should be written out. yes yes boolean true/false false N/A No DOMLS 17
jdk.xml.xsltcIsStandalone Indicates that the XSLTC serializer should treat the output as a standalone document. The property can be used to ensure a newline is written after the XML declaration. Unlike the property OMIT_XML_DECLARATION, this property does not have an effect on whether an XML declaration should be written out.

This property behaves similar to that for DOMLS above, except that it is for the XSLTC Serializer and its value is a String.

yes yes String yes/no no N/A No XSLTC Serializer 17
jdk.xml.cdataChunkSize Instructs the parser to return the data in a CData section in a single chunk when the property is zero or unspecified, or in multiple chunks when it is greater than zero. The parser shall split the data by linebreaks, and any chunks that are larger than the specified size to ones that are equal to or smaller than the size. yes yes Integer A positive integer. A value less than or equal to 0 indicates that the property is not specified. If the value is not an integer, a NumberFormatException is thrown. 0 N/A No SAX
StAX		 9
jdk.xml.extensionClassLoader Sets a non-null ClassLoader instance to be used for loading XSLTC java extension functions. no no Object A reference to a ClassLoader object. Null if the value is not specified. null N/A No Transform 9

The table below lists the Implementation Specific Features currently supported by the JDK. More features may be added in the future if necessary.

Implementation Specific Features
Full Name (prefix + name) [1] Description System Property [2] jaxp.properties [2] Value [3] Security [4] Supported Processor [5] Since [6]
Type Value Default Enforced
jdk.xml.enableExtensionFunctions Determines if XSLT and XPath extension functions are to be allowed. yes yes Boolean true or false. True indicates that extension functions are allowed; False otherwise. true false Yes Transform
XPath 		8
jdk.xml.overrideDefaultParser Enables the use of a 3rd party's parser implementation to override the system-default parser for the JDK's Transform, Validation and XPath implementations. true or false. True enables the use of 3rd party's parser implementations to override the system-default implementation during XML Transform, Validation or XPath operation. False disables the use of 3rd party's parser implementations. false false Yes Transform
Validation
XPath 		9
jdk.xml.resetSymbolTable Instructs the parser to reset its internal symbol table during each parse operation. true or false. True indicates that the SymbolTable associated with a parser needs to be reallocated during each parse operation.
False indicates that the parser's SymbolTable instance shall be reused during subsequent parse operations. 		false N/A No SAX 9

[1] The full name of a property should be used to set the property.

[2] A value "yes" indicates there is a corresponding System Property for the property, "no" otherwise.

[3] The value must be exactly as listed in this table, case-sensitive. The value of the corresponding System Property is the String representation of the property value. If the type is boolean, the system property is true only if it is "true"; If the type is String, the system property is true only if it is exactly the same string representing the positive value (e.g. "yes" for xsltcIsStandalone); The system property is false otherwise. If the type is Integer, the value of the System Property is the String representation of the value (e.g. "64000" for entityExpansionLimit).

[4] A value "yes" indicates the property is a Security Property. Refer to the Scope and Order on how secure processing may affect the value of a Security Property.

[5] One or more processors that support the property. The values of the field are IDs described in table Processors.

[6] Indicates the initial release the property is introduced.

Legacy Property Names (deprecated)

JDK releases prior to JDK 17 support the use of URI style prefix for properties. These legacy property names are deprecated as of JDK 17 and may be removed in future releases. If both new and legacy properties are set, the new property names take precedence regardless of how and where they are set. The overriding order as defined in Scope and Order thus becomes, in descending order:
  • The default value;
  • Value set by FEATURE_SECURE_PROCESSING;
  • Value set in jaxp.properties;
  • Value set as System Property;
  • Value set on factories or processors using legacy property names;
  • Value set on factories or processors using new property names.

The following table lists the properties and their corresponding legacy names.

Legacy Property Names (deprecated since 17)
Property Legacy Property Name(s)
jdk.xml.entityExpansionLimit http://www.oracle.com/xml/jaxp/properties/entityExpansionLimit
jdk.xml.elementAttributeLimit http://www.oracle.com/xml/jaxp/properties/elementAttributeLimit
jdk.xml.maxOccurLimit http://www.oracle.com/xml/jaxp/properties/maxOccurLimit
jdk.xml.totalEntitySizeLimit http://www.oracle.com/xml/jaxp/properties/totalEntitySizeLimit
jdk.xml.maxGeneralEntitySizeLimit http://www.oracle.com/xml/jaxp/properties/maxGeneralEntitySizeLimit
jdk.xml.maxParameterEntitySizeLimit http://www.oracle.com/xml/jaxp/properties/maxParameterEntitySizeLimit
jdk.xml.entityReplacementLimit http://www.oracle.com/xml/jaxp/properties/entityReplacementLimit
jdk.xml.maxElementDepth http://www.oracle.com/xml/jaxp/properties/maxElementDepth
jdk.xml.maxXMLNameLimit http://www.oracle.com/xml/jaxp/properties/maxXMLNameLimit
jdk.xml.isStandalone http://www.oracle.com/xml/jaxp/properties/isStandalone
jdk.xml.xsltcIsStandalone http://www.oracle.com/xml/is-standalone
http://www.oracle.com/xml/jaxp/properties/xsltcIsStandalone
jdk.xml.extensionClassLoader jdk.xml.transform.extensionClassLoader
jdk.xml.enableExtensionFunctions http://www.oracle.com/xml/jaxp/properties/enableExtensionFunctions
Since:
9