/*
* Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
* 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.sql;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.Writer;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
/**
* The mapping in the JavaTM programming language for the SQL XML type.
* XML is a built-in type that stores an XML value
* as a column value in a row of a database table.
* By default drivers implement an SQLXML object as
* a logical pointer to the XML data
* rather than the data itself.
* An SQLXML object is valid for the duration of the transaction in which it was created.
* <p>
* The SQLXML interface provides methods for accessing the XML value
* as a String, a Reader or Writer, or as a Stream. The XML value
* may also be accessed through a Source or set as a Result, which
* are used with XML Parser APIs such as DOM, SAX, and StAX, as
* well as with XSLT transforms and XPath evaluations.
* <p>
* Methods in the interfaces ResultSet, CallableStatement, and PreparedStatement,
* such as getSQLXML allow a programmer to access an XML value.
* In addition, this interface has methods for updating an XML value.
* <p>
* The XML value of the SQLXML instance may be obtained as a BinaryStream using
* <pre>
* SQLXML sqlxml = resultSet.getSQLXML(column);
* InputStream binaryStream = sqlxml.getBinaryStream();
* </pre>
* For example, to parse an XML value with a DOM parser:
* <pre>
* DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
* Document result = parser.parse(binaryStream);
* </pre>
* or to parse an XML value with a SAX parser to your handler:
* <pre>
* SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
* parser.parse(binaryStream, myHandler);
* </pre>
* or to parse an XML value with a StAX parser:
* <pre>
* XMLInputFactory factory = XMLInputFactory.newInstance();
* XMLStreamReader streamReader = factory.createXMLStreamReader(binaryStream);
* </pre>
* <p>
* Because databases may use an optimized representation for the XML,
* accessing the value through getSource() and
* setResult() can lead to improved processing performance
* without serializing to a stream representation and parsing the XML.
* <p>
* For example, to obtain a DOM Document Node:
* <pre>
* DOMSource domSource = sqlxml.getSource(DOMSource.class);
* Document document = (Document) domSource.getNode();
* </pre>
* or to set the value to a DOM Document Node to myNode:
* <pre>
* DOMResult domResult = sqlxml.setResult(DOMResult.class);
* domResult.setNode(myNode);
* </pre>
* or, to send SAX events to your handler:
* <pre>
* SAXSource saxSource = sqlxml.getSource(SAXSource.class);
* XMLReader xmlReader = saxSource.getXMLReader();
* xmlReader.setContentHandler(myHandler);
* xmlReader.parse(saxSource.getInputSource());
* </pre>
* or, to set the result value from SAX events:
* <pre>
* SAXResult saxResult = sqlxml.setResult(SAXResult.class);
* ContentHandler contentHandler = saxResult.getXMLReader().getContentHandler();
* contentHandler.startDocument();
* // set the XML elements and attributes into the result
* contentHandler.endDocument();
* </pre>
* or, to obtain StAX events:
* <pre>
* StAXSource staxSource = sqlxml.getSource(StAXSource.class);
* XMLStreamReader streamReader = staxSource.getXMLStreamReader();
* </pre>
* or, to set the result value from StAX events:
* <pre>
* StAXResult staxResult = sqlxml.setResult(StAXResult.class);
* XMLStreamWriter streamWriter = staxResult.getXMLStreamWriter();
* </pre>
* or, to perform XSLT transformations on the XML value using the XSLT in xsltFile
* output to file resultFile:
* <pre>
* File xsltFile = new File("a.xslt");
* File myFile = new File("result.xml");
* Transformer xslt = TransformerFactory.newInstance().newTransformer(new StreamSource(xsltFile));
* Source source = sqlxml.getSource(null);
* Result result = new StreamResult(myFile);
* xslt.transform(source, result);
* </pre>
* or, to evaluate an XPath expression on the XML value:
* <pre>
* XPath xpath = XPathFactory.newInstance().newXPath();
* DOMSource domSource = sqlxml.getSource(DOMSource.class);
* Document document = (Document) domSource.getNode();
* String expression = "/foo/@bar";
* String barValue = xpath.evaluate(expression, document);
* </pre>
* To set the XML value to be the result of an XSLT transform:
* <pre>
* File sourceFile = new File("source.xml");
* Transformer xslt = TransformerFactory.newInstance().newTransformer(new StreamSource(xsltFile));
* Source streamSource = new StreamSource(sourceFile);
* Result result = sqlxml.setResult(null);
* xslt.transform(streamSource, result);
* </pre>
* Any Source can be transformed to a Result using the identity transform
* specified by calling newTransformer():
* <pre>
* Transformer identity = TransformerFactory.newInstance().newTransformer();
* Source source = sqlxml.getSource(null);
* File myFile = new File("result.xml");
* Result result = new StreamResult(myFile);
* identity.transform(source, result);
* </pre>
* To write the contents of a Source to standard output:
* <pre>
* Transformer identity = TransformerFactory.newInstance().newTransformer();
* Source source = sqlxml.getSource(null);
* Result result = new StreamResult(System.out);
* identity.transform(source, result);
* </pre>
* To create a DOMSource from a DOMResult:
* <pre>
* DOMSource domSource = new DOMSource(domResult.getNode());
* </pre>
* <p>
* Incomplete or invalid XML values may cause an SQLException when
* set or the exception may occur when execute() occurs. All streams
* must be closed before execute() occurs or an SQLException will be thrown.
* <p>
* Reading and writing XML values to or from an SQLXML object can happen at most once.
* The conceptual states of readable and not readable determine if one
* of the reading APIs will return a value or throw an exception.
* The conceptual states of writable and not writable determine if one
* of the writing APIs will set a value or throw an exception.
* <p>
* The state moves from readable to not readable once free() or any of the
* reading APIs are called: getBinaryStream(), getCharacterStream(), getSource(), and getString().
* Implementations may also change the state to not writable when this occurs.
* <p>
* The state moves from writable to not writeable once free() or any of the
* writing APIs are called: setBinaryStream(), setCharacterStream(), setResult(), and setString().
* Implementations may also change the state to not readable when this occurs.
* <p>
* <p>
* All methods on the <code>SQLXML</code> interface must be fully implemented if the
* JDBC driver supports the data type.
*
* @see javax.xml.parsers
* @see javax.xml.stream
* @see javax.xml.transform
* @see javax.xml.xpath
* @since 1.6
*/
public interface SQLXML
{
/**
* This method closes this object and releases the resources that it held.
* The SQL XML object becomes invalid and neither readable or writeable
* when this method is called.
*
* After <code>free</code> has been called, any attempt to invoke a
* method other than <code>free</code> will result in a <code>SQLException</code>
* being thrown. If <code>free</code> is called multiple times, the subsequent
* calls to <code>free</code> are treated as a no-op.
* @throws SQLException if there is an error freeing the XML value.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
void free() throws SQLException;
/**
* Retrieves the XML value designated by this SQLXML instance as a stream.
* The bytes of the input stream are interpreted according to appendix F of the XML 1.0 specification.
* The behavior of this method is the same as ResultSet.getBinaryStream()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not readable when this method is called and
* may also become not writable depending on implementation.
*
* @return a stream containing the XML data.
* @throws SQLException if there is an error processing the XML value.
* An exception is thrown if the state is not readable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
InputStream getBinaryStream() throws SQLException;
/**
* Retrieves a stream that can be used to write the XML value that this SQLXML instance represents.
* The stream begins at position 0.
* The bytes of the stream are interpreted according to appendix F of the XML 1.0 specification
* The behavior of this method is the same as ResultSet.updateBinaryStream()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not writeable when this method is called and
* may also become not readable depending on implementation.
*
* @return a stream to which data can be written.
* @throws SQLException if there is an error processing the XML value.
* An exception is thrown if the state is not writable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
OutputStream setBinaryStream() throws SQLException;
/**
* Retrieves the XML value designated by this SQLXML instance as a java.io.Reader object.
* The format of this stream is defined by org.xml.sax.InputSource,
* where the characters in the stream represent the unicode code points for
* XML according to section 2 and appendix B of the XML 1.0 specification.
* Although an encoding declaration other than unicode may be present,
* the encoding of the stream is unicode.
* The behavior of this method is the same as ResultSet.getCharacterStream()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not readable when this method is called and
* may also become not writable depending on implementation.
*
* @return a stream containing the XML data.
* @throws SQLException if there is an error processing the XML value.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if the stream does not contain valid characters.
* An exception is thrown if the state is not readable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
Reader getCharacterStream() throws SQLException;
/**
* Retrieves a stream to be used to write the XML value that this SQLXML instance represents.
* The format of this stream is defined by org.xml.sax.InputSource,
* where the characters in the stream represent the unicode code points for
* XML according to section 2 and appendix B of the XML 1.0 specification.
* Although an encoding declaration other than unicode may be present,
* the encoding of the stream is unicode.
* The behavior of this method is the same as ResultSet.updateCharacterStream()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not writeable when this method is called and
* may also become not readable depending on implementation.
*
* @return a stream to which data can be written.
* @throws SQLException if there is an error processing the XML value.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if the stream does not contain valid characters.
* An exception is thrown if the state is not writable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
Writer setCharacterStream() throws SQLException;
/**
* Returns a string representation of the XML value designated by this SQLXML instance.
* The format of this String is defined by org.xml.sax.InputSource,
* where the characters in the stream represent the unicode code points for
* XML according to section 2 and appendix B of the XML 1.0 specification.
* Although an encoding declaration other than unicode may be present,
* the encoding of the String is unicode.
* The behavior of this method is the same as ResultSet.getString()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not readable when this method is called and
* may also become not writable depending on implementation.
*
* @return a string representation of the XML value designated by this SQLXML instance.
* @throws SQLException if there is an error processing the XML value.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if the stream does not contain valid characters.
* An exception is thrown if the state is not readable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
String getString() throws SQLException;
/**
* Sets the XML value designated by this SQLXML instance to the given String representation.
* The format of this String is defined by org.xml.sax.InputSource,
* where the characters in the stream represent the unicode code points for
* XML according to section 2 and appendix B of the XML 1.0 specification.
* Although an encoding declaration other than unicode may be present,
* the encoding of the String is unicode.
* The behavior of this method is the same as ResultSet.updateString()
* when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
* <p>
* The SQL XML object becomes not writeable when this method is called and
* may also become not readable depending on implementation.
*
* @param value the XML value
* @throws SQLException if there is an error processing the XML value.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if the stream does not contain valid characters.
* An exception is thrown if the state is not writable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
void setString(String value) throws SQLException;
/**
* Returns a Source for reading the XML value designated by this SQLXML instance.
* Sources are used as inputs to XML parsers and XSLT transformers.
* <p>
* Sources for XML parsers will have namespace processing on by default.
* The systemID of the Source is implementation dependent.
* <p>
* The SQL XML object becomes not readable when this method is called and
* may also become not writable depending on implementation.
* <p>
* Note that SAX is a callback architecture, so a returned
* SAXSource should then be set with a content handler that will
* receive the SAX events from parsing. The content handler
* will receive callbacks based on the contents of the XML.
* <pre>
* SAXSource saxSource = sqlxml.getSource(SAXSource.class);
* XMLReader xmlReader = saxSource.getXMLReader();
* xmlReader.setContentHandler(myHandler);
* xmlReader.parse(saxSource.getInputSource());
* </pre>
*
* @param sourceClass The class of the source, or null.
* If the class is null, a vendor specifc Source implementation will be returned.
* The following classes are supported at a minimum:
* <pre>
* javax.xml.transform.dom.DOMSource - returns a DOMSource
* javax.xml.transform.sax.SAXSource - returns a SAXSource
* javax.xml.transform.stax.StAXSource - returns a StAXSource
* javax.xml.transform.stream.StreamSource - returns a StreamSource
* </pre>
* @return a Source for reading the XML value.
* @throws SQLException if there is an error processing the XML value
* or if this feature is not supported.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if an XML parser exception occurs.
* An exception is thrown if the state is not readable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
<T extends Source> T getSource(Class<T> sourceClass) throws SQLException;
/**
* Returns a Result for setting the XML value designated by this SQLXML instance.
* <p>
* The systemID of the Result is implementation dependent.
* <p>
* The SQL XML object becomes not writeable when this method is called and
* may also become not readable depending on implementation.
* <p>
* Note that SAX is a callback architecture and the returned
* SAXResult has a content handler assigned that will receive the
* SAX events based on the contents of the XML. Call the content
* handler with the contents of the XML document to assign the values.
* <pre>
* SAXResult saxResult = sqlxml.setResult(SAXResult.class);
* ContentHandler contentHandler = saxResult.getXMLReader().getContentHandler();
* contentHandler.startDocument();
* // set the XML elements and attributes into the result
* contentHandler.endDocument();
* </pre>
*
* @param resultClass The class of the result, or null.
* If resultClass is null, a vendor specific Result implementation will be returned.
* The following classes are supported at a minimum:
* <pre>
* javax.xml.transform.dom.DOMResult - returns a DOMResult
* javax.xml.transform.sax.SAXResult - returns a SAXResult
* javax.xml.transform.stax.StAXResult - returns a StAXResult
* javax.xml.transform.stream.StreamResult - returns a StreamResult
* </pre>
* @return Returns a Result for setting the XML value.
* @throws SQLException if there is an error processing the XML value
* or if this feature is not supported.
* The getCause() method of the exception may provide a more detailed exception, for example,
* if an XML parser exception occurs.
* An exception is thrown if the state is not writable.
* @exception SQLFeatureNotSupportedException if the JDBC driver does not support
* this method
* @since 1.6
*/
<T extends Result> T setResult(Class<T> resultClass) throws SQLException;
}