/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * 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).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

package javax.xml.transform.stream;

import java.io.File;

import java.io.InputStream;

import java.io.Reader;

import javax.xml.transform.Source;

/**

 * <p>Acts as an holder for a transformation Source in the form

 * of a stream of XML markup.</p>

 *

 * <p><em>Note:</em> Due to their internal use of either a {@link Reader} or {@link InputStream} instance,

 * <code>StreamSource</code> instances may only be used once.</p>

 *

 * @author <a href="Jeff.Suttor@Sun.com">Jeff Suttor</a>

 * @since 1.4

 */

public class StreamSource implements Source {

    /** If {@link javax.xml.transform.TransformerFactory#getFeature}

     * returns true when passed this value as an argument,

     * the Transformer supports Source input of this type.

     */

    public static final String FEATURE =

        "http://javax.xml.transform.stream.StreamSource/feature";

    /**

     * <p>Zero-argument default constructor.  If this constructor is used, and

     * no Stream source is set using

     * {@link #setInputStream(java.io.InputStream inputStream)} or

     * {@link #setReader(java.io.Reader reader)}, then the

     * <code>Transformer</code> will

     * create an empty source {@link java.io.InputStream} using

     * {@link java.io.InputStream#InputStream() new InputStream()}.</p>

     *

     * @see javax.xml.transform.Transformer#transform(Source xmlSource, Result outputTarget)

     */

    public StreamSource() { }

    /**

     * Construct a StreamSource from a byte stream.  Normally,

     * a stream should be used rather than a reader, so

     * the XML parser can resolve character encoding specified

     * by the XML declaration.

     *

     * <p>If this constructor is used to process a stylesheet, normally

     * setSystemId should also be called, so that relative URI references

     * can be resolved.</p>

     *

     * @param inputStream A valid InputStream reference to an XML stream.

     */

    public StreamSource(InputStream inputStream) {

        setInputStream(inputStream);

    }

    /**

     * Construct a StreamSource from a byte stream.  Normally,

     * a stream should be used rather than a reader, so that

     * the XML parser can resolve character encoding specified

     * by the XML declaration.

     *

     * <p>This constructor allows the systemID to be set in addition

     * to the input stream, which allows relative URIs

     * to be processed.</p>

     *

     * @param inputStream A valid InputStream reference to an XML stream.

     * @param systemId Must be a String that conforms to the URI syntax.

     */

    public StreamSource(InputStream inputStream, String systemId) {

        setInputStream(inputStream);

        setSystemId(systemId);

    }

    /**

     * Construct a StreamSource from a character reader.  Normally,

     * a stream should be used rather than a reader, so that

     * the XML parser can resolve character encoding specified

     * by the XML declaration.  However, in many cases the encoding

     * of the input stream is already resolved, as in the case of

     * reading XML from a StringReader.

     *

     * @param reader A valid Reader reference to an XML character stream.

     */

    public StreamSource(Reader reader) {

        setReader(reader);

    }

    /**

     * Construct a StreamSource from a character reader.  Normally,

     * a stream should be used rather than a reader, so that

     * the XML parser may resolve character encoding specified

     * by the XML declaration.  However, in many cases the encoding

     * of the input stream is already resolved, as in the case of

     * reading XML from a StringReader.

     *

     * @param reader A valid Reader reference to an XML character stream.

     * @param systemId Must be a String that conforms to the URI syntax.

     */

    public StreamSource(Reader reader, String systemId) {

        setReader(reader);

        setSystemId(systemId);

    }

    /**

     * Construct a StreamSource from a URL.

     *

     * @param systemId Must be a String that conforms to the URI syntax.

     */

    public StreamSource(String systemId) {

        this.systemId = systemId;

    }

    /**

     * Construct a StreamSource from a File.

     *

     * @param f Must a non-null File reference.

     */

    public StreamSource(File f) {

        //convert file to appropriate URI, f.toURI().toASCIIString()

        //converts the URI to string as per rule specified in

        //RFC 2396,

        setSystemId(f.toURI().toASCIIString());

    }

    /**

     * Set the byte stream to be used as input.  Normally,

     * a stream should be used rather than a reader, so that

     * the XML parser can resolve character encoding specified

     * by the XML declaration.

     *

     * <p>If this Source object is used to process a stylesheet, normally

     * setSystemId should also be called, so that relative URL references

     * can be resolved.</p>

     *

     * @param inputStream A valid InputStream reference to an XML stream.

     */

    public void setInputStream(InputStream inputStream) {

        this.inputStream = inputStream;

    }

    /**

     * Get the byte stream that was set with setByteStream.

     *

     * @return The byte stream that was set with setByteStream, or null

     * if setByteStream or the ByteStream constructor was not called.

     */

    public InputStream getInputStream() {

        return inputStream;

    }

    /**

     * Set the input to be a character reader.  Normally,

     * a stream should be used rather than a reader, so that

     * the XML parser can resolve character encoding specified

     * by the XML declaration.  However, in many cases the encoding

     * of the input stream is already resolved, as in the case of

     * reading XML from a StringReader.

     *

     * @param reader A valid Reader reference to an XML CharacterStream.

     */

    public void setReader(Reader reader) {

        this.reader = reader;

    }

    /**

     * Get the character stream that was set with setReader.

     *

     * @return The character stream that was set with setReader, or null

     * if setReader or the Reader constructor was not called.

     */

    public Reader getReader() {

        return reader;

    }

    /**

     * Set the public identifier for this Source.

     *

     * <p>The public identifier is always optional: if the application

     * writer includes one, it will be provided as part of the

     * location information.</p>

     *

     * @param publicId The public identifier as a string.

     */

    public void setPublicId(String publicId) {

        this.publicId = publicId;

    }

    /**

     * Get the public identifier that was set with setPublicId.

     *

     * @return The public identifier that was set with setPublicId, or null

     * if setPublicId was not called.

     */

    public String getPublicId() {

        return publicId;

    }

    /**

     * Set the system identifier for this Source.

     *

     * <p>The system identifier is optional if there is a byte stream

     * or a character stream, but it is still useful to provide one,

     * since the application can use it to resolve relative URIs

     * and can include it in error messages and warnings (the parser

     * will attempt to open a connection to the URI only if

     * there is no byte stream or character stream specified).</p>

     *

     * @param systemId The system identifier as a URL string.

     */

    public void setSystemId(String systemId) {

        this.systemId = systemId;

    }

    /**

     * Get the system identifier that was set with setSystemId.

     *

     * @return The system identifier that was set with setSystemId, or null

     * if setSystemId was not called.

     */

    public String getSystemId() {

        return systemId;

    }

    /**

     * Set the system ID from a File reference.

     *

     * @param f Must a non-null File reference.

     */

    public void setSystemId(File f) {

        //convert file to appropriate URI, f.toURI().toASCIIString()

        //converts the URI to string as per rule specified in

        //RFC 2396,

        this.systemId = f.toURI().toASCIIString();

    }

    //////////////////////////////////////////////////////////////////////

    // Internal state.

    //////////////////////////////////////////////////////////////////////

    /**

     * The public identifier for this input source, or null.

     */

    private String publicId;

    /**

     * The system identifier as a URL string, or null.

     */

    private String systemId;

    /**

     * The byte stream for this Source, or null.

     */

    private InputStream inputStream;

    /**

     * The character stream for this Source, or null.

     */

    private Reader reader;

}