xml/stream/XMLOutputFactory.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package javax.xml.stream;

import com.sun.xml.internal.stream.XMLOutputFactoryImpl;
import javax.xml.transform.Result;

/**
 * Defines an abstract implementation of a factory for
 * getting XMLEventWriters and XMLStreamWriters.
 *
 * The following table defines the standard properties of this specification.
 * Each property varies in the level of support required by each implementation.
 * The level of support required is described in the 'Required' column.
 *
 *     <table class="striped">
 *     <caption>Configuration Parameters</caption>
 *     <thead>
 *      <tr>
 *        <th>Property Name</th>
 *        <th>Behavior</th>
 *        <th>Return type</th>
 *        <th>Default Value</th>
 *        <th>Required</th>
 *              </tr>
 *    </thead>
 *    <tbody>
 *         <tr><td>javax.xml.stream.isRepairingNamespaces</td><td>defaults prefixes
 *                 on the output side</td><td>Boolean</td><td>False</td><td>Yes</td></tr>
 *      </tbody>
 *   </table>
 *
 * <p>The following paragraphs describe the namespace and prefix repair algorithm:
 *
 * <p>The property can be set with the following code line:
 * {@code setProperty("javax.xml.stream.isRepairingNamespaces", new Boolean(true|false));}
 *
 * <p>This property specifies that the writer default namespace prefix declarations.
 * The default value is false.
 *
 * <p>If a writer isRepairingNamespaces it will create a namespace declaration
 * on the current StartElement for
 * any attribute that does not
 * currently have a namespace declaration in scope.  If the StartElement
 * has a uri but no prefix specified a prefix will be assigned, if the prefix
 * has not been declared in a parent of the current StartElement it will be declared
 * on the current StartElement.  If the defaultNamespace is bound and in scope
 * and the default namespace matches the URI of the attribute or StartElement
 * QName no prefix will be assigned.
 *
 * <p>If an element or attribute name has a prefix, but is not
 * bound to any namespace URI, then the prefix will be removed
 * during serialization.
 *
 * <p>If element and/or attribute names in the same start or
 * empty-element tag are bound to different namespace URIs and
 * are using the same prefix then the element or the first
 * occurring attribute retains the original prefix and the
 * following attributes have their prefixes replaced with a
 * new prefix that is bound to the namespace URIs of those
 * attributes.
 *
 * <p>If an element or attribute name uses a prefix that is
 * bound to a different URI than that inherited from the
 * namespace context of the parent of that element and there
 * is no namespace declaration in the context of the current
 * element then such a namespace declaration is added.
 *
 * <p>If an element or attribute name is bound to a prefix and
 * there is a namespace declaration that binds that prefix
 * to a different URI then that namespace declaration is
 * either removed if the correct mapping is inherited from
 * the parent context of that element, or changed to the
 * namespace URI of the element or attribute using that prefix.
 *
 * @version 1.2
 * @author Copyright (c) 2009, 2015 by Oracle Corporation. All Rights Reserved.
 * @see XMLInputFactory
 * @see XMLEventWriter
 * @see XMLStreamWriter
 * @since 1.6
 */
public abstract class XMLOutputFactory {
  /**
   * Property used to set prefix defaulting on the output side
   */
  public static final String IS_REPAIRING_NAMESPACES=
    "javax.xml.stream.isRepairingNamespaces";

  static final String DEFAULIMPL = "com.sun.xml.internal.stream.XMLOutputFactoryImpl";

  protected XMLOutputFactory(){}

   /**
   * Creates a new instance of the {@code XMLOutputFactory} builtin
   * system-default implementation.
   *
   * @return A new instance of the {@code XMLOutputFactory} builtin
   *         system-default implementation.
   *
   * @since 9
   */
  public static XMLOutputFactory newDefaultFactory() {
      return new XMLOutputFactoryImpl();
  }

  /**
   * Creates a new instance of the factory in exactly the same manner as the
   * {@link #newFactory()} method.
   * @throws FactoryConfigurationError if an instance of this factory cannot be loaded
   */
  public static XMLOutputFactory newInstance()
    throws FactoryConfigurationError
  {
    return FactoryFinder.find(XMLOutputFactory.class, DEFAULIMPL);
  }

  /**
   * Create a new instance of the factory.
   * <p>
   * This static method creates a new factory instance. This method uses the
   * following ordered lookup procedure to determine the XMLOutputFactory
   * implementation class to load:
   * <ul>
   * <li>
   *   Use the javax.xml.stream.XMLOutputFactory system property.
   * </li>
   * <li>
   *   <p>
   *   Use the configuration file "stax.properties". The file is in standard
   *   {@link java.util.Properties} format and typically located in the
   *   {@code conf} directory of the Java installation. It contains the fully qualified
   *   name of the implementation class with the key being the system property
   *   defined above.
   *
   *   <p>
   *   The stax.properties file is read only once by the implementation
   *   and its 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 in stax.properties after it has been read for the first time.
   *
   *   <p>
   *   Use the jaxp configuration file "jaxp.properties". The file is in the same
   *   format as stax.properties and will only be read if stax.properties does
   *   not exist.
   * </li>
   * <li>
   *   <p>
   *   Use the service-provider loading facility, defined by the
   *   {@link java.util.ServiceLoader} class, to attempt to locate and load an
   *   implementation of the service using the {@linkplain
   *   java.util.ServiceLoader#load(java.lang.Class) default loading mechanism}:
   *   the service-provider loading facility will use the {@linkplain
   *   java.lang.Thread#getContextClassLoader() current thread's context class loader}
   *   to attempt to load the service. If the context class
   *   loader is null, the {@linkplain
   *   ClassLoader#getSystemClassLoader() system class loader} will be used.
   * </li>
   * <li>
   *   <p>
   *   Otherwise, the {@linkplain #newDefaultFactory() system-default}
   *   implementation is returned.
   * </li>
   * </ul>
   * <p>
   * Once an application has obtained a reference to a XMLOutputFactory it
   * can use the factory to configure and obtain stream instances.
   * <p>
   * Note that this is a new method that replaces the deprecated newInstance() method.
   *   No changes in behavior are defined by this replacement method relative to the
   *   deprecated method.
   *
   * @throws FactoryConfigurationError in case of {@linkplain
   *   java.util.ServiceConfigurationError service configuration error} or if
   *   the implementation is not available or cannot be instantiated.
   */
  public static XMLOutputFactory newFactory()
    throws FactoryConfigurationError
  {
    return FactoryFinder.find(XMLOutputFactory.class, DEFAULIMPL);
  }

  /**
   * Create a new instance of the factory.
   *
   * @param factoryId             Name of the factory to find, same as
   *                              a property name
   * @param classLoader           classLoader to use
   * @return the factory implementation
   * @throws FactoryConfigurationError if an instance of this factory cannot be loaded
   *
   * @deprecated  This method has been deprecated because it returns an
   *              instance of XMLInputFactory, which is of the wrong class.
   *              Use the new method {@link #newFactory(java.lang.String,
   *              java.lang.ClassLoader)} instead.
   */
  @Deprecated(since="1.7")
  public static XMLInputFactory newInstance(String factoryId,
          ClassLoader classLoader)
          throws FactoryConfigurationError {
      //do not fallback if given classloader can't find the class, throw exception
      return FactoryFinder.find(XMLInputFactory.class, factoryId, classLoader, null);
  }

  /**
   * Create a new instance of the factory.
   * If the classLoader argument is null, then the ContextClassLoader is used.
   * <p>
   * This method uses the following ordered lookup procedure to determine
   * the XMLOutputFactory implementation class to load:
   * <ul>
   * <li>
   *   Use the value of the system property identified by {@code factoryId}.
   * </li>
   * <li>
   *   <p>
   *   Use the configuration file "stax.properties". The file is in standard
   *   {@link java.util.Properties} format and typically located in the
   *   {@code conf} directory of the Java installation. It contains the fully qualified
   *   name of the implementation class with the key being the system property
   *   defined above.
   *
   *   <p>
   *   The stax.properties file is read only once by the implementation
   *   and its 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 in stax.properties after it has been read for the first time.
   *
   *   <p>
   *   Use the jaxp configuration file "jaxp.properties". The file is in the same
   *   format as stax.properties and will only be read if stax.properties does
   *   not exist.
   * </li>
   * <li>
   *   <p>
   *   If {@code factoryId} is "javax.xml.stream.XMLOutputFactory",
   *   use the service-provider loading facility, defined by the
   *   {@link java.util.ServiceLoader} class, to attempt to {@linkplain
   *   java.util.ServiceLoader#load(java.lang.Class, java.lang.ClassLoader) locate and load}
   *   an implementation of the service using the specified {@code ClassLoader}.
   *   If {@code classLoader} is null, the {@linkplain
   *   java.util.ServiceLoader#load(java.lang.Class) default loading mechanism} will apply:
   *   That is, the service-provider loading facility will use the {@linkplain
   *   java.lang.Thread#getContextClassLoader() current thread's context class loader}
   *   to attempt to load the service. If the context class
   *   loader is null, the {@linkplain
   *   ClassLoader#getSystemClassLoader() system class loader} will be used.
   * </li>
   * <li>
   *   <p>
   *   Otherwise, throws a {@link FactoryConfigurationError}.
   * </li>
   * </ul>
   *
   * @apiNote The parameter factoryId defined here is inconsistent with that
   * of other JAXP factories where the first parameter is fully qualified
   * factory class name that provides implementation of the factory.
   *
   * <p>
   *   Note that this is a new method that replaces the deprecated
   *   {@link #newInstance(java.lang.String, java.lang.ClassLoader)
   *   newInstance(String factoryId, ClassLoader classLoader)} method.
   *   The original method was incorrectly defined to return XMLInputFactory.
   *
   *
   * @param factoryId             Name of the factory to find, same as
   *                              a property name
   * @param classLoader           classLoader to use
   * @return the factory implementation
   * @throws FactoryConfigurationError in case of {@linkplain
   *   java.util.ServiceConfigurationError service configuration error} or if
   *   the implementation is not available or cannot be instantiated.
   */
  public static XMLOutputFactory newFactory(String factoryId,
          ClassLoader classLoader)
          throws FactoryConfigurationError {
      //do not fallback if given classloader can't find the class, throw exception
      return FactoryFinder.find(XMLOutputFactory.class, factoryId, classLoader, null);
  }

  /**
   * Create a new XMLStreamWriter that writes to a writer
   * @param stream the writer to write to
   * @throws XMLStreamException
   */
  public abstract XMLStreamWriter createXMLStreamWriter(java.io.Writer stream) throws XMLStreamException;

  /**
   * Create a new XMLStreamWriter that writes to a stream
   * @param stream the stream to write to
   * @throws XMLStreamException
   */
  public abstract XMLStreamWriter createXMLStreamWriter(java.io.OutputStream stream) throws XMLStreamException;

  /**
   * Create a new XMLStreamWriter that writes to a stream
   * @param stream the stream to write to
   * @param encoding the encoding to use
   * @throws XMLStreamException
   */
  public abstract XMLStreamWriter createXMLStreamWriter(java.io.OutputStream stream,
                                         String encoding) throws XMLStreamException;

  /**
   * Create a new XMLStreamWriter that writes to a JAXP result.  This method is optional.
   * @param result the result to write to
   * @throws UnsupportedOperationException if this method is not
   * supported by this XMLOutputFactory
   * @throws XMLStreamException
   */
  public abstract XMLStreamWriter createXMLStreamWriter(Result result) throws XMLStreamException;


  /**
   * Create a new XMLEventWriter that writes to a JAXP result.  This method is optional.
   * @param result the result to write to
   * @throws UnsupportedOperationException if this method is not
   * supported by this XMLOutputFactory
   * @throws XMLStreamException
   */
  public abstract XMLEventWriter createXMLEventWriter(Result result) throws XMLStreamException;

  /**
   * Create a new XMLEventWriter that writes to a stream
   * @param stream the stream to write to
   * @throws XMLStreamException
   */
  public abstract XMLEventWriter createXMLEventWriter(java.io.OutputStream stream) throws XMLStreamException;


  /**
   * Create a new XMLEventWriter that writes to a stream
   * @param stream the stream to write to
   * @param encoding the encoding to use
   * @throws XMLStreamException
   */
  public abstract XMLEventWriter createXMLEventWriter(java.io.OutputStream stream,
                                                     String encoding) throws XMLStreamException;

  /**
   * Create a new XMLEventWriter that writes to a writer
   * @param stream the stream to write to
   * @throws XMLStreamException
   */
  public abstract XMLEventWriter createXMLEventWriter(java.io.Writer stream) throws XMLStreamException;

  /**
   * Allows the user to set specific features/properties on the underlying implementation.
   * @param name The name of the property
   * @param value The value of the property
   * @throws java.lang.IllegalArgumentException if the property is not supported
   */
  public abstract void setProperty(java.lang.String name,
                                    Object value)
    throws IllegalArgumentException;

  /**
   * Get a feature/property on the underlying implementation
   * @param name The name of the property
   * @return The value of the property
   * @throws java.lang.IllegalArgumentException if the property is not supported
   */
  public abstract Object getProperty(java.lang.String name)
    throws IllegalArgumentException;

  /**
   * Query the set of properties that this factory supports.
   *
   * @param name The name of the property (may not be null)
   * @return true if the property is supported and false otherwise
   */
  public abstract boolean isPropertySupported(String name);
}