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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

 *

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package com.sun.xml.internal.bind.v2.runtime;

import java.io.IOException;

import javax.xml.bind.annotation.XmlValue;

import javax.xml.datatype.XMLGregorianCalendar;

import javax.xml.namespace.QName;

import javax.xml.stream.XMLStreamException;

import com.sun.istack.internal.NotNull;

import com.sun.xml.internal.bind.api.AccessorException;

import com.sun.xml.internal.bind.v2.model.runtime.RuntimePropertyInfo;

import com.sun.xml.internal.bind.v2.runtime.reflect.opt.OptimizedTransducedAccessorFactory;

import org.xml.sax.SAXException;

/**

 * Responsible for converting a Java object to a lexical representation

 * and vice versa.

 *

 * <p>

 * An implementation of this interface hides how this conversion happens.

 *

 * <p>

 * {@link Transducer}s are immutable.

 *

 * @author Kohsuke Kawaguchi (kk@kohsuke.org)

 */

public interface Transducer<ValueT> {

    /**

     * If this {@link Transducer} is the default transducer for the <code>ValueT</code>,

     * this method returns true.

     *

     * Used exclusively by {@link OptimizedTransducedAccessorFactory#get(RuntimePropertyInfo)}

     */

    boolean isDefault();

    /**

     * If true, this {@link Transducer} doesn't declare any namespace,

     * and therefore {@link #declareNamespace(Object, XMLSerializer)} is no-op.

     *

     * It also means that the {@link #parse(CharSequence)} method

     * won't use the context parameter.

     */

    boolean useNamespace();

    /**

     * Declares the namespace URIs used in the given value to {@code w}.

     *

     * @param o

     *      never be null.

     * @param w

     *      may be null if {@code !{@link #useNamespace()}}.

     */

    void declareNamespace( ValueT o, XMLSerializer w ) throws AccessorException;

    /**

     * Converts the given value to its lexical representation.

     *

     * @param o

     *      never be null.

     * @return

     *      always non-null valid lexical representation.

     */

    @NotNull CharSequence print(@NotNull ValueT o) throws AccessorException;

    /**

     * Converts the lexical representation to a value object.

     *

     * @param lexical

     *      never be null.

     * @throws AccessorException

     *      if the transducer is used to parse an user bean that uses {@link XmlValue},

     *      then this exception may occur when it tries to set the leaf value to the bean.

     * @throws SAXException

     *      if the lexical form is incorrect, the error should be reported

     *      and SAXException may thrown (or it can return null to recover.)

     */

    ValueT parse(CharSequence lexical) throws AccessorException, SAXException;

    /**

     * Sends the result of the {@link #print(Object)} operation

     * to one of the {@link XMLSerializer#text(String, String)} method,

     * but with the best representation of the value, not necessarily String.

     */

    void writeText(XMLSerializer w, ValueT o, String fieldName) throws IOException, SAXException, XMLStreamException, AccessorException;

    /**

     * Sends the result of the {@link #print(Object)} operation

     * to one of the {@link XMLSerializer#leafElement(Name, String, String)} method.

     * but with the best representation of the value, not necessarily String.

     */

    void writeLeafElement(XMLSerializer w, Name tagName, @NotNull ValueT o, String fieldName) throws IOException, SAXException, XMLStreamException, AccessorException;

    /**

     * Transducers implicitly work against a single XML type,

     * but sometimes (most notably {@link XMLGregorianCalendar},

     * an instance may choose different XML types.

     *

     * @return

     *      return non-null from this method allows transducers

     *      to specify the type it wants to marshal to.

     *      Most of the time this method returns null, in which case

     *      the implicitly associated type will be used.

     */

    QName getTypeName(@NotNull ValueT instance);

}