javax.xml.validation
class SchemaFactory

java.lang.Object javax.xml.validation.SchemaFactory

Most common way to construct:

String language = …;

SchemaFactory factory = SchemaFactory.newInstance(language);

Based on 37 examples

public abstract class SchemaFactory
extends Object

Factory that creates {@link Schema} objects. Entry-point to the validation API.

{@link SchemaFactory} is a schema compiler. It reads external representations of schemas and prepares them for validation.

The {@link SchemaFactory} class is not thread-safe. In other words, it is the application's responsibility to ensure that at most one thread is using a {@link SchemaFactory} object at any given moment. Implementations are encouraged to mark methods as synchronized to protect themselves from broken clients.

{@link SchemaFactory} is not re-entrant. While one of the newSchema methods is being invoked, applications may not attempt to recursively invoke the newSchema method, even from the same thread.

Schema Language

This spec uses a namespace URI to designate a schema language. The following table shows the values defined by this specification.

To be compliant with the spec, the implementation is only required to support W3C XML Schema 1.0. However, if it chooses to support other schema languages listed here, it must conform to the relevant behaviors described in this spec.

Schema languages not listed here are expected to introduce their own URIs to represent themselves. The {@link SchemaFactory} class is capable of locating other implementations for other schema languages at run-time.

Note that because the XML DTD is strongly tied to the parsing process and has a significant effect on the parsing process, it is impossible to define the DTD validation as a process independent from parsing. For this reason, this specification does not define the semantics for the XML DTD. This doesn't prohibit implentors from implementing it in a way they see fit, but users are warned that any DTD validation implemented on this interface necessarily deviate from the XML DTD semantics as defined in the XML 1.0.

SchemaFactory

protected SchemaFactory()

Constructor for derived classes.

The constructor does nothing.

Derived classes must create {@link SchemaFactory} objects that have null {@link ErrorHandler} and null {@link LSResourceResolver}.

getErrorHandler

public abstract ErrorHandler getErrorHandler()

Gets the current {@link ErrorHandler} set to this {@link SchemaFactory}.

Returns:

This method returns the object that was last set through the {@link #setErrorHandler(ErrorHandler)} method, or null if that method has never been called since this {@link SchemaFactory} has created.

getFeature

public boolean getFeature(String name)
                   throws SAXNotRecognizedException,
                          SAXNotSupportedException

Look up the value of a feature flag.

The feature name is any fully-qualified URI. It is possible for a {@link SchemaFactory} to recognize a feature name but temporarily be unable to return its value.

Implementors are free (and encouraged) to invent their own features, using names built on their own URIs.

Parameters:

name - The feature name, which is a non-null fully-qualified URI.

Returns:

The current value of the feature (true or false).

Throws:

SAXNotRecognizedException - If the feature value can't be assigned or retrieved.

SAXNotSupportedException - When the {@link SchemaFactory} recognizes the feature name but cannot determine its value at this time.

getProperty

public Object getProperty(String name)
                   throws SAXNotRecognizedException,
                          SAXNotSupportedException

Look up the value of a property.

The property name is any fully-qualified URI. It is possible for a {@link SchemaFactory} to recognize a property name but temporarily be unable to return its value.

{@link SchemaFactory}s are not required to recognize any specific property names.

Implementors are free (and encouraged) to invent their own properties, using names built on their own URIs.

Parameters:

name - The property name, which is a non-null fully-qualified URI.

Returns:

The current value of the property.

Throws:

SAXNotRecognizedException - If the property value can't be assigned or retrieved.

SAXNotSupportedException - When the XMLReader recognizes the property name but cannot determine its value at this time.

getResourceResolver

public abstract LSResourceResolver getResourceResolver()

Gets the current {@link LSResourceResolver} set to this {@link SchemaFactory}.

Returns:

This method returns the object that was last set through the {@link #setResourceResolver(LSResourceResolver)} method, or null if that method has never been called since this {@link SchemaFactory} has created.

isSchemaLanguageSupported

public abstract boolean isSchemaLanguageSupported(String schemaLanguage)

Is specified schema supported by this SchemaFactory?

Parameters:

schemaLanguage - Specifies the schema language which the returned SchemaFactory will understand. schemaLanguage must specify a valid schema language.

Returns:

true if SchemaFactory supports schemaLanguage, else false.

newInstance

public static final SchemaFactory newInstance(String schemaLanguage)

Lookup an implementation of the SchemaFactory that supports the specified schema language and return it.

To find a SchemaFactory object for a given schema language, this method looks the following places in the following order where "the class loader" refers to the context class loader:

1. If the system property "javax.xml.validation.SchemaFactory:schemaLanguage" is present (where schemaLanguage is the parameter to this method), then its value is read as a class name. The method will try to create a new instance of this class by using the class loader, and returns it if it is successfully created.
2. $java.home/lib/jaxp.properties is read and the value associated with the key being the system property above is looked for. If present, the value is processed just like above.

3. The class loader is asked for service provider provider-configuration files matching javax.xml.validation.SchemaFactory in the resource directory META-INF/services. See the JAR File Specification for file format and parsing rules. Each potential service provider is required to implement the method:

           {@link #isSchemaLanguageSupported(String schemaLanguage)}
        

   The first service provider found in class loader order that supports the specified schema language is returned.
4. Platform default SchemaFactory is located in a implementation specific way. There must be a platform default SchemaFactory for W3C XML Schema.

If everything fails, {@link IllegalArgumentException} will be thrown.

Tip for Trouble-shooting:

See {@link java.util.Properties#load(java.io.InputStream)} for exactly how a property file is parsed. In particular, colons ':' need to be escaped in a property file, so make sure schema language URIs are properly escaped in it. For example:

 http\://www.w3.org/2001/XMLSchema=org.acme.foo.XSSchemaFactory
 

Parameters:

schemaLanguage - Specifies the schema language which the returned SchemaFactory will understand. See the list of available schema languages for the possible values.

Returns:

New instance of a SchemaFactory

newInstance

public static SchemaFactory newInstance(String schemaLanguage,
                                        String factoryClassName,
                                        ClassLoader classLoader)

Obtain a new instance of a SchemaFactory from class name. SchemaFactory is returned if specified factory class name supports the specified schema language. This function is useful when there are multiple providers in the classpath. It gives more control to the application as it can specify which provider should be loaded.

Tip for Trouble-shooting

Setting the jaxp.debug system property will cause this method to print a lot of debug messages to System.err about what it is doing and where it is looking at.

If you have problems try:

 java -Djaxp.debug=1 YourProgram ....
 

Parameters:

schemaLanguage - Specifies the schema language which the returned SchemaFactory will understand. See the list of available schema languages for the possible values.

factoryClassName - fully qualified factory class name that provides implementation of javax.xml.validation.SchemaFactory.

classLoader - ClassLoader used to load the factory class. If null current Thread's context classLoader is used to load the factory class.

Returns:

New instance of a SchemaFactory

newSchema

public abstract Schema newSchema()
                          throws SAXException

Creates a special {@link Schema} object.

The exact semantics of the returned {@link Schema} object depend on the schema language for which this {@link SchemaFactory} is created.

Also, implementations are allowed to use implementation-specific property/feature to alter the semantics of this method.

Implementors and developers should pay particular attention to how the features set on this {@link SchemaFactory} are processed by this special {@link Schema}. In some cases, for example, when the {@link SchemaFactory} and the class actually loading the schema come from different implementations, it may not be possible for {@link SchemaFactory} features to be inherited automatically. Developers should make sure that features, such as secure processing, are explicitly set in both places.

W3C XML Schema 1.0

For XML Schema, this method creates a {@link Schema} object that performs validation by using location hints specified in documents.

The returned {@link Schema} object assumes that if documents refer to the same URL in the schema location hints, they will always resolve to the same schema document. This asusmption allows implementations to reuse parsed results of schema documents so that multiple validations against the same schema will run faster.

Note that the use of schema location hints introduces a vulnerability to denial-of-service attacks.

RELAX NG

RELAX NG does not support this operation.

Returns:

Always return non-null valid {@link Schema} object.

Throws:

SAXException - If this operation is supported but failed for some reason.

newSchema

public Schema newSchema(File schema)
                 throws SAXException

Parses the specified File as a schema and returns it as a Schema.

This is a convenience method for {@link #newSchema(Source schema)}.

Parameters:

schema - File that represents a schema.

Returns:

New Schema from parsing schema.

Throws:

SAXException - If a SAX error occurs during parsing.

newSchema

public Schema newSchema(Source schema)
                 throws SAXException

Parses the specified source as a schema and returns it as a schema.

This is a convenience method for {@link #newSchema(Source[] schemas)}.

Parameters:

schema - Source that represents a schema.

Returns:

New Schema from parsing schema.

Throws:

SAXException - If a SAX error occurs during parsing.

newSchema

public abstract Schema newSchema(Source[] schemas)
                          throws SAXException

Parses the specified source(s) as a schema and returns it as a schema.

The callee will read all the {@link Source}s and combine them into a single schema. The exact semantics of the combination depends on the schema language that this {@link SchemaFactory} object is created for.

When an {@link ErrorHandler} is set, the callee will report all the errors found in sources to the handler. If the handler throws an exception, it will abort the schema compilation and the same exception will be thrown from this method. Also, after an error is reported to a handler, the callee is allowed to abort the further processing by throwing it. If an error handler is not set, the callee will throw the first error it finds in the sources.

W3C XML Schema 1.0

The resulting schema contains components from the specified sources. The same result would be achieved if all these sources were imported, using appropriate values for schemaLocation and namespace, into a single schema document with a different targetNamespace and no components of its own, if the import elements were given in the same order as the sources. Section 4.2.3 of the XML Schema recommendation describes the options processors have in this regard. While a processor should be consistent in its treatment of JAXP schema sources and XML Schema imports, the behaviour between JAXP-compliant parsers may vary; in particular, parsers may choose to ignore all but the first <import> for a given namespace, regardless of information provided in schemaLocation.

If the parsed set of schemas includes error(s) as specified in the section 5.1 of the XML Schema spec, then the error must be reported to the {@link ErrorHandler}.

RELAX NG

For RELAX NG, this method must throw {@link UnsupportedOperationException} if schemas.length!=1.

Parameters:

schemas - inputs to be parsed. {@link SchemaFactory} is required to recognize {@link javax.xml.transform.sax.SAXSource}, {@link StreamSource}, {@link javax.xml.transform.stax.StAXSource}, and {@link javax.xml.transform.dom.DOMSource}. Input schemas must be XML documents or XML elements and must not be null. For backwards compatibility, the results of passing anything other than a document or element are implementation-dependent. Implementations must either recognize and process the input or thrown an IllegalArgumentException.

Returns:

Always return a non-null valid {@link Schema} object. Note that when an error has been reported, there is no guarantee that the returned {@link Schema} object is meaningful.

Throws:

SAXException - If an error is found during processing the specified inputs. When an {@link ErrorHandler} is set, errors are reported to there first. See {@link #setErrorHandler(ErrorHandler)}.

newSchema

public Schema newSchema(URL schema)
                 throws SAXException

Parses the specified URL as a schema and returns it as a Schema.

This is a convenience method for {@link #newSchema(Source schema)}.

Parameters:

schema - URL that represents a schema.

Returns:

New Schema from parsing schema.

Throws:

SAXException - If a SAX error occurs during parsing.

setErrorHandler

public abstract void setErrorHandler(ErrorHandler errorHandler)

Sets the {@link ErrorHandler} to receive errors encountered during the newSchema method invocation.

Error handler can be used to customize the error handling process during schema parsing. When an {@link ErrorHandler} is set, errors found during the parsing of schemas will be first sent to the {@link ErrorHandler}.

The error handler can abort the parsing of a schema immediately by throwing {@link SAXException} from the handler. Or for example it can print an error to the screen and try to continue the processing by returning normally from the {@link ErrorHandler}

If any {@link Throwable} (or instances of its derived classes) is thrown from an {@link ErrorHandler}, the caller of the newSchema method will be thrown the same {@link Throwable} object.

{@link SchemaFactory} is not allowed to throw {@link SAXException} without first reporting it to {@link ErrorHandler}.

Applications can call this method even during a {@link Schema} is being parsed.

When the {@link ErrorHandler} is null, the implementation will behave as if the following {@link ErrorHandler} is set:

 class DraconianErrorHandler implements {@link ErrorHandler} {
     public void fatalError( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
         throw e;
     }
     public void error( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
         throw e;
     }
     public void warning( {@link org.xml.sax.SAXParseException} e ) throws {@link SAXException} {
         // noop
     }
 }
 

When a new {@link SchemaFactory} object is created, initially this field is set to null. This field will NOT be inherited to {@link Schema}s, {@link Validator}s, or {@link ValidatorHandler}s that are created from this {@link SchemaFactory}.

Parameters:

errorHandler - A new error handler to be set. This parameter can be null.

setFeature

public void setFeature(String name,
                       boolean value)
                throws SAXNotRecognizedException,
                       SAXNotSupportedException

Set a feature for this SchemaFactory, {@link Schema}s created by this factory, and by extension, {@link Validator}s and {@link ValidatorHandler}s created by those {@link Schema}s.

Implementors and developers should pay particular attention to how the special {@link Schema} object returned by {@link #newSchema()} is processed. In some cases, for example, when the SchemaFactory and the class actually loading the schema come from different implementations, it may not be possible for SchemaFactory features to be inherited automatically. Developers should make sure that features, such as secure processing, are explicitly set in both places.

The feature name is any fully-qualified URI. It is possible for a {@link SchemaFactory} to expose a feature value but to be unable to change the current value.

All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature. When the feature is:

• true: the implementation will limit XML processing to conform to implementation limits. Examples include enity expansion limits and XML Schema constructs that would consume large amounts of resources. If XML processing is limited for security reasons, it will be reported via a call to the registered {@link ErrorHandler#fatalError(SAXParseException exception)}. See {@link #setErrorHandler(ErrorHandler errorHandler)}.
• false: the implementation will processing XML according to the XML specifications without regard to possible implementation limits.

Parameters:

name - The feature name, which is a non-null fully-qualified URI.

value - The requested value of the feature (true or false).

Throws:

SAXNotRecognizedException - If the feature value can't be assigned or retrieved.

SAXNotSupportedException - When the {@link SchemaFactory} recognizes the feature name but cannot set the requested value.

setProperty

public void setProperty(String name,
                        Object object)
                 throws SAXNotRecognizedException,
                        SAXNotSupportedException

Set the value of a property.

The property name is any fully-qualified URI. It is possible for a {@link SchemaFactory} to recognize a property name but to be unable to change the current value.

{@link SchemaFactory}s are not required to recognize setting any specific property names.

Parameters:

name - The property name, which is a non-null fully-qualified URI.

object - The requested value for the property.

Throws:

SAXNotRecognizedException - If the property value can't be assigned or retrieved.

SAXNotSupportedException - When the {@link SchemaFactory} recognizes the property name but cannot set the requested value.

setResourceResolver

public abstract void setResourceResolver(LSResourceResolver resourceResolver)

Sets the {@link LSResourceResolver} to customize resource resolution when parsing schemas.

{@link SchemaFactory} uses a {@link LSResourceResolver} when it needs to locate external resources while parsing schemas, although exactly what constitutes "locating external resources" is up to each schema language. For example, for W3C XML Schema, this includes files <include>d or <import>ed, and DTD referenced from schema files, etc.

Applications can call this method even during a {@link Schema} is being parsed.

When the {@link LSResourceResolver} is null, the implementation will behave as if the following {@link LSResourceResolver} is set:

 class DumbDOMResourceResolver implements {@link LSResourceResolver} {
     public {@link org.w3c.dom.ls.LSInput} resolveResource(
         String publicId, String systemId, String baseURI) {
         
         return null; // always return null
     }
 }
 

If a {@link LSResourceResolver} throws a {@link RuntimeException} (or instances of its derived classes), then the {@link SchemaFactory} will abort the parsing and the caller of the newSchema method will receive the same {@link RuntimeException}.

When a new {@link SchemaFactory} object is created, initially this field is set to null. This field will NOT be inherited to {@link Schema}s, {@link Validator}s, or {@link ValidatorHandler}s that are created from this {@link SchemaFactory}.

Parameters:

resourceResolver - A new resource resolver to be set. This parameter can be null.