javax.xml

## Class XMLConstants

- java.lang.Object
- - javax.xml.XMLConstants

-     public final class XMLConstants
      extends Object

  Utility class to contain basic XML values as constants.

  Since:
    1.5
  See Also:
    Extensible Markup Language (XML) 1.1, Extensible Markup Language (XML) 1.0 (Second Edition), XML 1.0 Second Edition Specification Errata, Namespaces in XML 1.1, Namespaces in XML, Namespaces in XML Errata, XML Schema Part 1: Structures

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static String` | `ACCESS_EXTERNAL_DTD` Property: accessExternalDTD
    `static String` | `ACCESS_EXTERNAL_SCHEMA` Property: accessExternalSchema
    `static String` | `ACCESS_EXTERNAL_STYLESHEET` Property: accessExternalStylesheet
    `static String` | `DEFAULT_NS_PREFIX` Prefix to use to represent the default XML Namespace.
    `static String` | `FEATURE_SECURE_PROCESSING` Feature for secure processing.
    `static String` | `NULL_NS_URI` Namespace URI to use to represent that there is no Namespace.
    `static String` | `RELAXNG_NS_URI` RELAX NG Namespace URI.
    `static String` | `W3C_XML_SCHEMA_INSTANCE_NS_URI` W3C XML Schema Instance Namespace URI.
    `static String` | `W3C_XML_SCHEMA_NS_URI` W3C XML Schema Namespace URI.
    `static String` | `W3C_XPATH_DATATYPE_NS_URI` W3C XPath Datatype Namespace URI.
    `static String` | `XML_DTD_NS_URI` XML Document Type Declaration Namespace URI as an arbitrary value.
    `static String` | `XML_NS_PREFIX` The official XML Namespace prefix.
    `static String` | `XML_NS_URI` The official XML Namespace name URI.
    `static String` | `XMLNS_ATTRIBUTE` The official XML attribute used for specifying XML Namespace declarations.
    `static String` | `XMLNS_ATTRIBUTE_NS_URI` The official XML attribute used for specifying XML Namespace declarations, `XMLConstants.XMLNS_ATTRIBUTE`, Namespace name URI.

  - ### Method Summary

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Field Detail

    - #### NULL_NS_URI

          public static final String NULL_NS_URI

      Namespace URI to use to represent that there is no Namespace.

      Defined by the Namespace specification to be "".

      See Also:
        Namespaces in XML, 5.2 Namespace Defaulting, Constant Field Values

    - #### DEFAULT_NS_PREFIX

          public static final String DEFAULT_NS_PREFIX

      Prefix to use to represent the default XML Namespace.

      Defined by the XML specification to be "".

      See Also:
        Namespaces in XML, 3. Qualified Names, Constant Field Values

    - #### XML_NS_URI

          public static final String XML_NS_URI

      The official XML Namespace name URI.

      Defined by the XML specification to be "`http://www.w3.org/XML/1998/namespace`".

      See Also:
        Namespaces in XML, 3. Qualified Names, Constant Field Values

    - #### XML_NS_PREFIX

          public static final String XML_NS_PREFIX

      The official XML Namespace prefix.

      Defined by the XML specification to be "`xml`".

      See Also:
        Namespaces in XML, 3. Qualified Names<, Constant Field Values

    - #### XMLNS_ATTRIBUTE_NS_URI

          public static final String XMLNS_ATTRIBUTE_NS_URI

      The official XML attribute used for specifying XML Namespace declarations, `XMLConstants.XMLNS_ATTRIBUTE`, Namespace name URI.

      Defined by the XML specification to be "`http://www.w3.org/2000/xmlns/`".

      See Also:
        Namespaces in XML, 3. Qualified Names, Namespaces in XML Errata, Constant Field Values

    - #### XMLNS_ATTRIBUTE

          public static final String XMLNS_ATTRIBUTE

      The official XML attribute used for specifying XML Namespace declarations.

      It is NOT valid to use as a prefix. Defined by the XML specification to be "`xmlns`".

      See Also:
        Namespaces in XML, 3. Qualified Names, Constant Field Values

    - #### W3C_XML_SCHEMA_NS_URI

          public static final String W3C_XML_SCHEMA_NS_URI

      W3C XML Schema Namespace URI.

      Defined to be "`http://www.w3.org/2001/XMLSchema`".

      See Also:
        XML Schema Part 1: Structures, 2.6 Schema-Related Markup in Documents Being Validated, Constant Field Values

    - #### W3C_XML_SCHEMA_INSTANCE_NS_URI

          public static final String W3C_XML_SCHEMA_INSTANCE_NS_URI

      W3C XML Schema Instance Namespace URI.

      Defined to be "`http://www.w3.org/2001/XMLSchema-instance`".

      See Also:
        XML Schema Part 1: Structures, 2.6 Schema-Related Markup in Documents Being Validated, Constant Field Values

    - #### W3C_XPATH_DATATYPE_NS_URI

          public static final String W3C_XPATH_DATATYPE_NS_URI

      W3C XPath Datatype Namespace URI.

      Defined to be "`http://www.w3.org/2003/11/xpath-datatypes`".

      See Also:
        XQuery 1.0 and XPath 2.0 Data Model, Constant Field Values

    - #### XML_DTD_NS_URI

          public static final String XML_DTD_NS_URI

      XML Document Type Declaration Namespace URI as an arbitrary value.

      Since not formally defined by any existing standard, arbitrarily define to be "`http://www.w3.org/TR/REC-xml`".

      See Also:
        Constant Field Values

    - #### RELAXNG_NS_URI

          public static final String RELAXNG_NS_URI

      RELAX NG Namespace URI.

      Defined to be "`http://relaxng.org/ns/structure/1.0`".

      See Also:
        RELAX NG Specification, Constant Field Values

    - #### FEATURE_SECURE_PROCESSING

          public static final String FEATURE_SECURE_PROCESSING

      Feature for secure processing.

      - `true` instructs the implementation to process XML securely. This may set limits on XML constructs to avoid conditions such as denial of service attacks.
      - `false` instructs the implementation to process XML in accordance with the XML specifications ignoring security issues such as limits on XML constructs to avoid conditions such as denial of service attacks.
      See Also:
        Constant Field Values

    - #### ACCESS_EXTERNAL_DTD

          public static final String ACCESS_EXTERNAL_DTD

      Property: accessExternalDTD

      Restrict access to external DTDs and external Entity References to the protocols specified. If access is denied due to the restriction of this property, a runtime exception that is specific to the context is thrown. In the case of `SAXParser` for example, `SAXException` is thrown.

      Value: a list of protocols separated by comma. A protocol is the scheme portion of a `URI`, or in the case of the JAR protocol, "jar" plus the scheme portion separated by colon. A scheme is defined as:

      > scheme = alpha *( alpha | digit | "+" | "-" | "." )
      > where alpha = a-z and A-Z.
      > And the JAR protocol:
      > jar[:scheme]
      > Protocols including the keyword "jar" are case-insensitive. Any whitespaces as defined by `Character.isSpaceChar(char)` in the value will be ignored. Examples of protocols are file, http, jar:file.

      Default value: The default value is implementation specific and therefore not specified. The following options are provided for consideration:

      > - an empty string to deny all access to external references;
      > - a specific protocol, such as file, to give permission to only the protocol;
      > - the keyword "all" to grant permission to all protocols.
      > When FEATURE_SECURE_PROCESSING is enabled, it is recommended that implementations restrict external connections by default, though this may cause problems for applications that process XML/XSD/XSL with external references.

      Granting all access: the keyword "all" grants permission to all protocols.

      System Property: The value of this property can be set or overridden by system property `javax.xml.accessExternalDTD`.

      ${JAVA_HOME}/lib/jaxp.properties: This configuration file is in standard `Properties` format. If the file exists and the system property is specified, its value will be used to override the default of the property.

      Since:
        1.7
      See Also:
        Constant Field Values

    - #### ACCESS_EXTERNAL_SCHEMA

          public static final String ACCESS_EXTERNAL_SCHEMA

      Property: accessExternalSchema

      Restrict access to the protocols specified for external reference set by the schemaLocation attribute, Import and Include element. If access is denied due to the restriction of this property, a runtime exception that is specific to the context is thrown. In the case of `SchemaFactory` for example, org.xml.sax.SAXException is thrown.

      Value: a list of protocols separated by comma. A protocol is the scheme portion of a `URI`, or in the case of the JAR protocol, "jar" plus the scheme portion separated by colon. A scheme is defined as:

      > scheme = alpha *( alpha | digit | "+" | "-" | "." )
      > where alpha = a-z and A-Z.
      > And the JAR protocol:
      > jar[:scheme]
      > Protocols including the keyword "jar" are case-insensitive. Any whitespaces as defined by `Character.isSpaceChar(char)` in the value will be ignored. Examples of protocols are file, http, jar:file.

      Default value: The default value is implementation specific and therefore not specified. The following options are provided for consideration:

      > - an empty string to deny all access to external references;
      > - a specific protocol, such as file, to give permission to only the protocol;
      > - the keyword "all" to grant permission to all protocols.
      > When FEATURE_SECURE_PROCESSING is enabled, it is recommended that implementations restrict external connections by default, though this may cause problems for applications that process XML/XSD/XSL with external references.

      Granting all access: the keyword "all" grants permission to all protocols.

      System Property: The value of this property can be set or overridden by system property `javax.xml.accessExternalSchema`

      ${JAVA_HOME}/lib/jaxp.properties: This configuration file is in standard java.util.Properties format. If the file exists and the system property is specified, its value will be used to override the default of the property.

      Since:
        1.7
      See Also:
        Constant Field Values

    - #### ACCESS_EXTERNAL_STYLESHEET

          public static final String ACCESS_EXTERNAL_STYLESHEET

      Property: accessExternalStylesheet

      Restrict access to the protocols specified for external references set by the stylesheet processing instruction, Import and Include element, and document function. If access is denied due to the restriction of this property, a runtime exception that is specific to the context is thrown. In the case of constructing new `Transformer` for example, `TransformerConfigurationException` will be thrown by the `TransformerFactory`.

      Value: a list of protocols separated by comma. A protocol is the scheme portion of a `URI`, or in the case of the JAR protocol, "jar" plus the scheme portion separated by colon. A scheme is defined as:

      > scheme = alpha *( alpha | digit | "+" | "-" | "." )
      > where alpha = a-z and A-Z.
      > And the JAR protocol:
      > jar[:scheme]
      > Protocols including the keyword "jar" are case-insensitive. Any whitespaces as defined by `Character.isSpaceChar(char)` in the value will be ignored. Examples of protocols are file, http, jar:file.

      Default value: The default value is implementation specific and therefore not specified. The following options are provided for consideration:

      > - an empty string to deny all access to external references;
      > - a specific protocol, such as file, to give permission to only the protocol;
      > - the keyword "all" to grant permission to all protocols.
      > When FEATURE_SECURE_PROCESSING is enabled, it is recommended that implementations restrict external connections by default, though this may cause problems for applications that process XML/XSD/XSL with external references.

      Granting all access: the keyword "all" grants permission to all protocols.

      System Property: The value of this property can be set or overridden by system property `javax.xml.accessExternalStylesheet`

      ${JAVA_HOME}/lib/jaxp.properties: This configuration file is in standard java.util.Properties format. If the file exists and the system property is specified, its value will be used to override the default of the property.

      Since:
        1.7
      See Also:
        Constant Field Values

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