An instance of this class can be obtained with the
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.
- Since:
- 1.4
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Constructor Summary
ModifierConstructorDescriptionprotected
Default constructor is protected on purpose. -
Method Summary
Modifier and TypeMethodDescriptionabstract void
Clear all parameters set with setParameter.abstract ErrorListener
Get the error event handler in effect for the transformation.abstract Properties
Get a copy of the output properties for the transformation.abstract String
getOutputProperty
(String name) Get an output property that is in effect for the transformer.abstract Object
getParameter
(String name) Get a parameter that was explicitly set with setParameter.abstract URIResolver
Get an object that will be used to resolve URIs used in document().void
reset()
Reset thisTransformer
to its original configuration.abstract void
setErrorListener
(ErrorListener listener) Set the error event listener in effect for the transformation.abstract void
setOutputProperties
(Properties oformat) Set the output properties for the transformation.abstract void
setOutputProperty
(String name, String value) Set an output property that will be in effect for the transformation.abstract void
setParameter
(String name, Object value) Add a parameter for the transformation.abstract void
setURIResolver
(URIResolver resolver) Set an object that will be used to resolve URIs used in document().abstract void
Transform the XMLSource
to aResult
.
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Constructor Details
-
Transformer
protected Transformer()Default constructor is protected on purpose.
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Method Details
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reset
public void reset()Reset this
Transformer
to its original configuration.Transformer
is reset to the same state as when it was created withTransformerFactory.newTransformer()
,TransformerFactory.newTransformer(Source source)
orTemplates.newTransformer()
.reset()
is designed to allow the reuse of existingTransformer
s thus saving resources associated with the creation of newTransformer
s.The reset
Transformer
is not guaranteed to have the sameURIResolver
orErrorListener
Object
s, e.g.Object.equals(Object obj)
. It is guaranteed to have a functionally equalURIResolver
andErrorListener
.- Throws:
UnsupportedOperationException
- When implementation does not override this method.- Since:
- 1.5
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transform
Transform the XML
Source
to aResult
. Specific transformation behavior is determined by the settings of theTransformerFactory
in effect when theTransformer
was instantiated and any modifications made to theTransformer
instance.An empty
Source
is represented as an empty document as constructed byDocumentBuilder.newDocument()
. The result of transforming an emptySource
depends on the transformation behavior; it is not always an emptyResult
.- Parameters:
xmlSource
- The XML input to transform.outputTarget
- TheResult
of transforming thexmlSource
.- Throws:
TransformerException
- If an unrecoverable error occurs during the course of the transformation.
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setParameter
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.
- Parameters:
name
- The name of the parameter, which may begin with a namespace URI in curly braces ({}).value
- The value object. This can be any valid Java object. It is up to the processor to provide the proper object conversion or to simply pass the object on for use in an extension.- Throws:
NullPointerException
- If value is null.
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getParameter
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.
- Parameters:
name
- ofObject
to get- Returns:
- A parameter that has been set with setParameter.
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clearParameters
public abstract void clearParameters()Clear all parameters set with setParameter. -
setURIResolver
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.
- Parameters:
resolver
- An object that implements the URIResolver interface, or null.
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getURIResolver
Get an object that will be used to resolve URIs used in document().- Returns:
- An object that implements the URIResolver interface, or null.
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setOutputProperties
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.
AnIllegalArgumentException
is thrown if any of the argument keys are not recognized and are not namespace qualified.- Parameters:
oformat
- A set of output properties that will be used to override any of the same properties in affect for the transformation.- Throws:
IllegalArgumentException
- When keys are not recognized and are not namespace qualified.- See Also:
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getOutputProperties
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
setOutputProperty(java.lang.String, java.lang.String)
,setOutputProperties(java.util.Properties)
, in the stylesheet, or the default properties, while getOutputProperties().get(String key) will only retrieve properties that were explicitly set bysetOutputProperty(java.lang.String, java.lang.String)
,setOutputProperties(java.util.Properties)
, 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
setOutputProperties
.- Returns:
- A copy of the set of output properties in effect for the next transformation.
- See Also:
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setOutputProperty
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
setOutputProperties(java.util.Properties)
won't be effected by calling this method.- Parameters:
name
- A non-null String that specifies an output property name, which may be namespace qualified.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 Also:
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getOutputProperty
Get an output property that is in effect for the transformer.
If a property has been set using
setOutputProperty(java.lang.String, java.lang.String)
, that value will be returned. Otherwise, if a property is explicitly specified in the stylesheet, that value will be returned. If the value of the property has been defaulted, that is, if no value has been set explicitly either withsetOutputProperty(java.lang.String, java.lang.String)
or in the stylesheet, the result may vary depending on implementation and input stylesheet.- Parameters:
name
- A non-null String that specifies an output property name, which may be namespace qualified.- Returns:
- The string value of the output property, or null if no property was found.
- Throws:
IllegalArgumentException
- If the property is not supported.- See Also:
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setErrorListener
Set the error event listener in effect for the transformation.- Parameters:
listener
- The new error listener.- Throws:
IllegalArgumentException
- if listener is null.
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getErrorListener
Get the error event handler in effect for the transformation. Implementations must provide a default error listener.- Returns:
- The current error handler, which should never be null.
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