javax.xml.transform.Transformer Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// $Id: Transformer.java 446598 2006-09-15 12:55:40Z jeremias $
package javax.xml.transform;
import java.util.Properties;
/**
* An instance of this abstract class can transform a
* source tree into a result tree.
*
* An instance of this class can be obtained with the
* {@link TransformerFactory#newTransformer TransformerFactory.newTransformer}
* method. This instance may then be used to process XML from a
* variety of sources and write the transformation output to a
* variety of sinks.
*
* An object of this class may not be used in multiple threads
* running concurrently. Different Transformers may be used
* concurrently by different threads.
*
* A Transformer may be used multiple times. Parameters and
* output properties are preserved across transformations.
*
* @author Jeff Suttor
* @version $Revision: 446598 $, $Date: 2006-09-15 08:55:40 -0400 (Fri, 15 Sep 2006) $
*/
public abstract class Transformer {
/**
* Default constructor is protected on purpose.
*/
protected Transformer() { }
/**
* Reset this Transformer to its original configuration.
*
* Transformer is reset to the same state as when it was created with
* {@link TransformerFactory#newTransformer()},
* {@link TransformerFactory#newTransformer(Source source)} or
* {@link Templates#newTransformer()}.
* reset() is designed to allow the reuse of existing Transformers
* thus saving resources associated with the creation of new Transformers.
*
* The reset Transformer is not guaranteed to have the same {@link URIResolver}
* or {@link ErrorListener} Objects, e.g. {@link Object#equals(Object obj)}.
* It is guaranteed to have a functionally equal URIResolver
* and ErrorListener.
*
* @since 1.5
*/
public void reset() {
// implementors should override this method
throw new UnsupportedOperationException(
"This Transformer, \"" + this.getClass().getName() + "\", does not support the reset functionality."
+ " Specification \"" + this.getClass().getPackage().getSpecificationTitle() + "\""
+ " version \"" + this.getClass().getPackage().getSpecificationVersion() + "\""
);
}
/**
* Transform the XML Source to a Result.
* Specific transformation behavior is determined by the settings of the
* TransformerFactory in effect when the
* Transformer was instantiated and any modifications made to
* the Transformer instance.
*
* An empty Source is represented as an empty document
* as constructed by {@link javax.xml.parsers.DocumentBuilder#newDocument()}.
* The result of transforming an empty Source depends on
* the transformation behavior; it is not always an empty
* Result.
*
* @param xmlSource The XML input to transform.
* @param outputTarget The Result of transforming the
* xmlSource.
*
* @throws TransformerException If an unrecoverable error occurs
* during the course of the transformation.
*/
public abstract void transform(Source xmlSource, Result outputTarget)
throws TransformerException;
/**
* Add a parameter for the transformation.
*
* Pass a qualified name as a two-part string, the namespace URI
* enclosed in curly braces ({}), followed by the local name. If the
* name has a null URL, the String only contain the local name. An
* application can safely check for a non-null URI by testing to see if the
* first character of the name is a '{' character.
* For example, if a URI and local name were obtained from an element
* defined with <xyz:foo
* xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>,
* then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo".
* Note that no prefix is used.
*
* @param name The name of the parameter, which may begin with a
* namespace URI in curly braces ({}).
* @param value The value object. This can be any valid Java object. It is
* up to the processor to provide the proper object coersion or to simply
* pass the object on for use in an extension.
*
* @throws NullPointerException If value is null.
*/
public abstract void setParameter(String name, Object value);
/**
* Get a parameter that was explicitly set with setParameter.
*
* This method does not return a default parameter value, which
* cannot be determined until the node context is evaluated during
* the transformation process.
*
* @param name of Object to get
* @return A parameter that has been set with setParameter.
*/
public abstract Object getParameter(String name);
/**
*
Set a list of parameters.
*
* Note that the list of parameters is specified as a
* Properties Object which limits the parameter
* values to Strings. Multiple calls to
* {@link #setParameter(String name, Object value)} should be used when the
* desired values are non-String Objects.
* The parameter names should conform as specified in
* {@link #setParameter(String name, Object value)}.
* An IllegalArgumentException is thrown if any names do not
* conform.
*
* New parameters in the list are added to any existing parameters.
* If the name of a new parameter is equal to the name of an existing
* parameter as determined by {@link java.lang.Object#equals(Object obj)},
* the existing parameter is set to the new value.
*
* @param params Parameters to set.
*
* @throws IllegalArgumentException If any parameter names do not conform
* to the naming rules.
*/
/**
* Clear all parameters set with setParameter.
*/
public abstract void clearParameters();
/**
* Set an object that will be used to resolve URIs used in
* document().
*
* If the resolver argument is null, the URIResolver value will
* be cleared and the transformer will no longer have a resolver.
*
* @param resolver An object that implements the URIResolver interface,
* or null.
*/
public abstract void setURIResolver(URIResolver resolver);
/**
* Get an object that will be used to resolve URIs used in
* document().
*
* @return An object that implements the URIResolver interface,
* or null.
*/
public abstract URIResolver getURIResolver();
/**
* Set the output properties for the transformation. These
* properties will override properties set in the Templates
* with xsl:output.
*
* If argument to this function is null, any properties
* previously set are removed, and the value will revert to the value
* defined in the templates object.
*
* Pass a qualified property key name as a two-part string, the namespace
* URI enclosed in curly braces ({}), followed by the local name. If the
* name has a null URL, the String only contain the local name. An
* application can safely check for a non-null URI by testing to see if the
* first character of the name is a '{' character.
* For example, if a URI and local name were obtained from an element
* defined with <xyz:foo
* xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>,
* then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo".
* Note that no prefix is used.
* An IllegalArgumentException is thrown if any of the
* argument keys are not recognized and are not namespace qualified.
*
* @param oformat A set of output properties that will be
* used to override any of the same properties in affect
* for the transformation.
*
* @see javax.xml.transform.OutputKeys
* @see java.util.Properties
*
*/
public abstract void setOutputProperties(Properties oformat);
/**
* Get a copy of the output properties for the transformation.
*
* The properties returned should contain properties set by the user,
* and properties set by the stylesheet, and these properties
* are "defaulted" by default properties specified by
* section 16 of the
* XSL Transformations (XSLT) W3C Recommendation. The properties that
* were specifically set by the user or the stylesheet should be in the base
* Properties list, while the XSLT default properties that were not
* specifically set should be the default Properties list. Thus,
* getOutputProperties().getProperty(String key) will obtain any
* property in that was set by {@link #setOutputProperty},
* {@link #setOutputProperties}, in the stylesheet, or the default
* properties, while
* getOutputProperties().get(String key) will only retrieve properties
* that were explicitly set by {@link #setOutputProperty},
* {@link #setOutputProperties}, or in the stylesheet.
*
* Note that mutation of the Properties object returned will not
* effect the properties that the transformer contains.
*
* If any of the argument keys are not recognized and are not
* namespace qualified, the property will be ignored and not returned.
* In other words the behaviour is not orthogonal with
* {@link #setOutputProperties setOutputProperties}.
*
* @return A copy of the set of output properties in effect for
* the next transformation.
*
* @see javax.xml.transform.OutputKeys
* @see java.util.Properties
* @see
* XSL Transformations (XSLT) Version 1.0
*/
public abstract Properties getOutputProperties();
/**
* Set an output property that will be in effect for the
* transformation.
*
* Pass a qualified property name as a two-part string, the namespace URI
* enclosed in curly braces ({}), followed by the local name. If the
* name has a null URL, the String only contain the local name. An
* application can safely check for a non-null URI by testing to see if the
* first character of the name is a '{' character.
* For example, if a URI and local name were obtained from an element
* defined with <xyz:foo
* xmlns:xyz="http://xyz.foo.com/yada/baz.html"/>,
* then the qualified name would be "{http://xyz.foo.com/yada/baz.html}foo".
* Note that no prefix is used.
*
* The Properties object that was passed to {@link #setOutputProperties}
* won't be effected by calling this method.
*
* @param name A non-null String that specifies an output
* property name, which may be namespace qualified.
* @param value The non-null string value of the output property.
*
* @throws IllegalArgumentException If the property is not supported, and is
* not qualified with a namespace.
*
* @see javax.xml.transform.OutputKeys
*/
public abstract void setOutputProperty(String name, String value)
throws IllegalArgumentException;
/**
* Get an output property that is in effect for the
* transformer. The property specified may be a property
* that was set with setOutputProperty, or it may be a
* property specified in the stylesheet.
*
* @param name A non-null String that specifies an output
* property name, which may be namespace qualified.
*
* @return The string value of the output property, or null
* if no property was found.
*
* @throws IllegalArgumentException If the property is not supported.
*
* @see javax.xml.transform.OutputKeys
*/
public abstract String getOutputProperty(String name)
throws IllegalArgumentException;
/**
* Set the error event listener in effect for the transformation.
*
* @param listener The new error listener.
* @throws IllegalArgumentException if listener is null.
*/
public abstract void setErrorListener(ErrorListener listener)
throws IllegalArgumentException;
/**
* Get the error event handler in effect for the transformation.
* Implementations must provide a default error listener.
*
* @return The current error handler, which should never be null.
*/
public abstract ErrorListener getErrorListener();
}