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1   /*
2    * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
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7    * published by the Free Software Foundation.  Oracle designates this
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9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
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20   *
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25  
26  package java.sql;
27  
28  import java.io.InputStream;
29  import java.io.OutputStream;
30  import java.io.Reader;
31  import java.io.Writer;
32  
33  import javax.xml.transform.Result;
34  import javax.xml.transform.Source;
35  
36  /**
37   * The mapping in the JavaTM programming language for the SQL XML type.
38   * XML is a built-in type that stores an XML value
39   * as a column value in a row of a database table.
40   * By default drivers implement an SQLXML object as
41   * a logical pointer to the XML data
42   * rather than the data itself.
43   * An SQLXML object is valid for the duration of the transaction in which it was created.
44   * <p>
45   * The SQLXML interface provides methods for accessing the XML value
46   * as a String, a Reader or Writer, or as a Stream.  The XML value
47   * may also be accessed through a Source or set as a Result, which
48   * are used with XML Parser APIs such as DOM, SAX, and StAX, as
49   * well as with XSLT transforms and XPath evaluations.
50   * <p>
51   * Methods in the interfaces ResultSet, CallableStatement, and PreparedStatement,
52   * such as getSQLXML allow a programmer to access an XML value.
53   * In addition, this interface has methods for updating an XML value.
54   * <p>
55   * The XML value of the SQLXML instance may be obtained as a BinaryStream using
56   * <pre>
57   *   SQLXML sqlxml = resultSet.getSQLXML(column);
58   *   InputStream binaryStream = sqlxml.getBinaryStream();
59   * </pre>
60   * For example, to parse an XML value with a DOM parser:
61   * <pre>
62   *   DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
63   *   Document result = parser.parse(binaryStream);
64   * </pre>
65   * or to parse an XML value with a SAX parser to your handler:
66   * <pre>
67   *   SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
68   *   parser.parse(binaryStream, myHandler);
69   * </pre>
70   * or to parse an XML value with a StAX parser:
71   * <pre>
72   *   XMLInputFactory factory = XMLInputFactory.newInstance();
73   *   XMLStreamReader streamReader = factory.createXMLStreamReader(binaryStream);
74   * </pre>
75   * <p>
76   * Because databases may use an optimized representation for the XML,
77   * accessing the value through getSource() and
78   * setResult() can lead to improved processing performance
79   * without serializing to a stream representation and parsing the XML.
80   * <p>
81   * For example, to obtain a DOM Document Node:
82   * <pre>
83   *   DOMSource domSource = sqlxml.getSource(DOMSource.class);
84   *   Document document = (Document) domSource.getNode();
85   * </pre>
86   * or to set the value to a DOM Document Node to myNode:
87   * <pre>
88   *   DOMResult domResult = sqlxml.setResult(DOMResult.class);
89   *   domResult.setNode(myNode);
90   * </pre>
91   * or, to send SAX events to your handler:
92   * <pre>
93   *   SAXSource saxSource = sqlxml.getSource(SAXSource.class);
94   *   XMLReader xmlReader = saxSource.getXMLReader();
95   *   xmlReader.setContentHandler(myHandler);
96   *   xmlReader.parse(saxSource.getInputSource());
97   * </pre>
98   * or, to set the result value from SAX events:
99   * <pre>
100  *   SAXResult saxResult = sqlxml.setResult(SAXResult.class);
101  *   ContentHandler contentHandler = saxResult.getHandler();
102  *   contentHandler.startDocument();
103  *   // set the XML elements and attributes into the result
104  *   contentHandler.endDocument();
105  * </pre>
106  * or, to obtain StAX events:
107  * <pre>
108  *   StAXSource staxSource = sqlxml.getSource(StAXSource.class);
109  *   XMLStreamReader streamReader = staxSource.getXMLStreamReader();
110  * </pre>
111  * or, to set the result value from StAX events:
112  * <pre>
113  *   StAXResult staxResult = sqlxml.setResult(StAXResult.class);
114  *   XMLStreamWriter streamWriter = staxResult.getXMLStreamWriter();
115  * </pre>
116  * or, to perform XSLT transformations on the XML value using the XSLT in xsltFile
117  * output to file resultFile:
118  * <pre>
119  *   File xsltFile = new File("a.xslt");
120  *   File myFile = new File("result.xml");
121  *   Transformer xslt = TransformerFactory.newInstance().newTransformer(new StreamSource(xsltFile));
122  *   Source source = sqlxml.getSource(null);
123  *   Result result = new StreamResult(myFile);
124  *   xslt.transform(source, result);
125  * </pre>
126  * or, to evaluate an XPath expression on the XML value:
127  * <pre>
128  *   XPath xpath = XPathFactory.newInstance().newXPath();
129  *   DOMSource domSource = sqlxml.getSource(DOMSource.class);
130  *   Document document = (Document) domSource.getNode();
131  *   String expression = "/foo/@bar";
132  *   String barValue = xpath.evaluate(expression, document);
133  * </pre>
134  * To set the XML value to be the result of an XSLT transform:
135  * <pre>
136  *   File sourceFile = new File("source.xml");
137  *   Transformer xslt = TransformerFactory.newInstance().newTransformer(new StreamSource(xsltFile));
138  *   Source streamSource = new StreamSource(sourceFile);
139  *   Result result = sqlxml.setResult(null);
140  *   xslt.transform(streamSource, result);
141  * </pre>
142  * Any Source can be transformed to a Result using the identity transform
143  * specified by calling newTransformer():
144  * <pre>
145  *   Transformer identity = TransformerFactory.newInstance().newTransformer();
146  *   Source source = sqlxml.getSource(null);
147  *   File myFile = new File("result.xml");
148  *   Result result = new StreamResult(myFile);
149  *   identity.transform(source, result);
150  * </pre>
151  * To write the contents of a Source to standard output:
152  * <pre>
153  *   Transformer identity = TransformerFactory.newInstance().newTransformer();
154  *   Source source = sqlxml.getSource(null);
155  *   Result result = new StreamResult(System.out);
156  *   identity.transform(source, result);
157  * </pre>
158  * To create a DOMSource from a DOMResult:
159  * <pre>
160  *    DOMSource domSource = new DOMSource(domResult.getNode());
161  * </pre>
162  * <p>
163  * Incomplete or invalid XML values may cause an SQLException when
164  * set or the exception may occur when execute() occurs.  All streams
165  * must be closed before execute() occurs or an SQLException will be thrown.
166  * <p>
167  * Reading and writing XML values to or from an SQLXML object can happen at most once.
168  * The conceptual states of readable and not readable determine if one
169  * of the reading APIs will return a value or throw an exception.
170  * The conceptual states of writable and not writable determine if one
171  * of the writing APIs will set a value or throw an exception.
172  * <p>
173  * The state moves from readable to not readable once free() or any of the
174  * reading APIs are called: getBinaryStream(), getCharacterStream(), getSource(), and getString().
175  * Implementations may also change the state to not writable when this occurs.
176  * <p>
177  * The state moves from writable to not writeable once free() or any of the
178  * writing APIs are called: setBinaryStream(), setCharacterStream(), setResult(), and setString().
179  * Implementations may also change the state to not readable when this occurs.
180  *
181  * <p>
182  * All methods on the <code>SQLXML</code> interface must be fully implemented if the
183  * JDBC driver supports the data type.
184  *
185  * @see javax.xml.parsers
186  * @see javax.xml.stream
187  * @see javax.xml.transform
188  * @see javax.xml.xpath
189  * @since 1.6
190  */
191 public interface SQLXML
192 {
193   /**
194    * This method closes this object and releases the resources that it held.
195    * The SQL XML object becomes invalid and neither readable or writeable
196    * when this method is called.
197    *
198    * After <code>free</code> has been called, any attempt to invoke a
199    * method other than <code>free</code> will result in a <code>SQLException</code>
200    * being thrown.  If <code>free</code> is called multiple times, the subsequent
201    * calls to <code>free</code> are treated as a no-op.
202    * @throws SQLException if there is an error freeing the XML value.
203    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
204    * this method
205    * @since 1.6
206    */
207   void free() throws SQLException;
208 
209   /**
210    * Retrieves the XML value designated by this SQLXML instance as a stream.
211    * The bytes of the input stream are interpreted according to appendix F of the XML 1.0 specification.
212    * The behavior of this method is the same as ResultSet.getBinaryStream()
213    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
214    * <p>
215    * The SQL XML object becomes not readable when this method is called and
216    * may also become not writable depending on implementation.
217    *
218    * @return a stream containing the XML data.
219    * @throws SQLException if there is an error processing the XML value.
220    *   An exception is thrown if the state is not readable.
221    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
222    * this method
223    * @since 1.6
224    */
225   InputStream getBinaryStream() throws SQLException;
226 
227   /**
228    * Retrieves a stream that can be used to write the XML value that this SQLXML instance represents.
229    * The stream begins at position 0.
230    * The bytes of the stream are interpreted according to appendix F of the XML 1.0 specification
231    * The behavior of this method is the same as ResultSet.updateBinaryStream()
232    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
233    * <p>
234    * The SQL XML object becomes not writeable when this method is called and
235    * may also become not readable depending on implementation.
236    *
237    * @return a stream to which data can be written.
238    * @throws SQLException if there is an error processing the XML value.
239    *   An exception is thrown if the state is not writable.
240    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
241    * this method
242    * @since 1.6
243    */
244   OutputStream setBinaryStream() throws SQLException;
245 
246   /**
247    * Retrieves the XML value designated by this SQLXML instance as a java.io.Reader object.
248    * The format of this stream is defined by org.xml.sax.InputSource,
249    * where the characters in the stream represent the unicode code points for
250    * XML according to section 2 and appendix B of the XML 1.0 specification.
251    * Although an encoding declaration other than unicode may be present,
252    * the encoding of the stream is unicode.
253    * The behavior of this method is the same as ResultSet.getCharacterStream()
254    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
255    * <p>
256    * The SQL XML object becomes not readable when this method is called and
257    * may also become not writable depending on implementation.
258    *
259    * @return a stream containing the XML data.
260    * @throws SQLException if there is an error processing the XML value.
261    *   The getCause() method of the exception may provide a more detailed exception, for example,
262    *   if the stream does not contain valid characters.
263    *   An exception is thrown if the state is not readable.
264    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
265    * this method
266    * @since 1.6
267    */
268   Reader getCharacterStream() throws SQLException;
269 
270   /**
271    * Retrieves a stream to be used to write the XML value that this SQLXML instance represents.
272    * The format of this stream is defined by org.xml.sax.InputSource,
273    * where the characters in the stream represent the unicode code points for
274    * XML according to section 2 and appendix B of the XML 1.0 specification.
275    * Although an encoding declaration other than unicode may be present,
276    * the encoding of the stream is unicode.
277    * The behavior of this method is the same as ResultSet.updateCharacterStream()
278    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
279    * <p>
280    * The SQL XML object becomes not writeable when this method is called and
281    * may also become not readable depending on implementation.
282    *
283    * @return a stream to which data can be written.
284    * @throws SQLException if there is an error processing the XML value.
285    *   The getCause() method of the exception may provide a more detailed exception, for example,
286    *   if the stream does not contain valid characters.
287    *   An exception is thrown if the state is not writable.
288    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
289    * this method
290    * @since 1.6
291    */
292   Writer setCharacterStream() throws SQLException;
293 
294   /**
295    * Returns a string representation of the XML value designated by this SQLXML instance.
296    * The format of this String is defined by org.xml.sax.InputSource,
297    * where the characters in the stream represent the unicode code points for
298    * XML according to section 2 and appendix B of the XML 1.0 specification.
299    * Although an encoding declaration other than unicode may be present,
300    * the encoding of the String is unicode.
301    * The behavior of this method is the same as ResultSet.getString()
302    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
303    * <p>
304    * The SQL XML object becomes not readable when this method is called and
305    * may also become not writable depending on implementation.
306    *
307    * @return a string representation of the XML value designated by this SQLXML instance.
308    * @throws SQLException if there is an error processing the XML value.
309    *   The getCause() method of the exception may provide a more detailed exception, for example,
310    *   if the stream does not contain valid characters.
311    *   An exception is thrown if the state is not readable.
312    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
313    * this method
314    * @since 1.6
315    */
316   String getString() throws SQLException;
317 
318   /**
319    * Sets the XML value designated by this SQLXML instance to the given String representation.
320    * The format of this String is defined by org.xml.sax.InputSource,
321    * where the characters in the stream represent the unicode code points for
322    * XML according to section 2 and appendix B of the XML 1.0 specification.
323    * Although an encoding declaration other than unicode may be present,
324    * the encoding of the String is unicode.
325    * The behavior of this method is the same as ResultSet.updateString()
326    * when the designated column of the ResultSet has a type java.sql.Types of SQLXML.
327    * <p>
328    * The SQL XML object becomes not writeable when this method is called and
329    * may also become not readable depending on implementation.
330    *
331    * @param value the XML value
332    * @throws SQLException if there is an error processing the XML value.
333    *   The getCause() method of the exception may provide a more detailed exception, for example,
334    *   if the stream does not contain valid characters.
335    *   An exception is thrown if the state is not writable.
336    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
337    * this method
338    * @since 1.6
339    */
340   void setString(String value) throws SQLException;
341 
342   /**
343    * Returns a Source for reading the XML value designated by this SQLXML instance.
344    * Sources are used as inputs to XML parsers and XSLT transformers.
345    * <p>
346    * Sources for XML parsers will have namespace processing on by default.
347    * The systemID of the Source is implementation dependent.
348    * <p>
349    * The SQL XML object becomes not readable when this method is called and
350    * may also become not writable depending on implementation.
351    * <p>
352    * Note that SAX is a callback architecture, so a returned
353    * SAXSource should then be set with a content handler that will
354    * receive the SAX events from parsing.  The content handler
355    * will receive callbacks based on the contents of the XML.
356    * <pre>
357    *   SAXSource saxSource = sqlxml.getSource(SAXSource.class);
358    *   XMLReader xmlReader = saxSource.getXMLReader();
359    *   xmlReader.setContentHandler(myHandler);
360    *   xmlReader.parse(saxSource.getInputSource());
361    * </pre>
362    *
363    * @param <T> the type of the class modeled by this Class object
364    * @param sourceClass The class of the source, or null.
365    * If the class is null, a vendor specific Source implementation will be returned.
366    * The following classes are supported at a minimum:
367    * <pre>
368    *   javax.xml.transform.dom.DOMSource - returns a DOMSource
369    *   javax.xml.transform.sax.SAXSource - returns a SAXSource
370    *   javax.xml.transform.stax.StAXSource - returns a StAXSource
371    *   javax.xml.transform.stream.StreamSource - returns a StreamSource
372    * </pre>
373    * @return a Source for reading the XML value.
374    * @throws SQLException if there is an error processing the XML value
375    *   or if this feature is not supported.
376    *   The getCause() method of the exception may provide a more detailed exception, for example,
377    *   if an XML parser exception occurs.
378    *   An exception is thrown if the state is not readable.
379    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
380    * this method
381    * @since 1.6
382    */
383   <T extends Source> T getSource(Class<T> sourceClass) throws SQLException;
384 
385   /**
386    * Returns a Result for setting the XML value designated by this SQLXML instance.
387    * <p>
388    * The systemID of the Result is implementation dependent.
389    * <p>
390    * The SQL XML object becomes not writeable when this method is called and
391    * may also become not readable depending on implementation.
392    * <p>
393    * Note that SAX is a callback architecture and the returned
394    * SAXResult has a content handler assigned that will receive the
395    * SAX events based on the contents of the XML.  Call the content
396    * handler with the contents of the XML document to assign the values.
397    * <pre>
398    *   SAXResult saxResult = sqlxml.setResult(SAXResult.class);
399    *   ContentHandler contentHandler = saxResult.getXMLReader().getContentHandler();
400    *   contentHandler.startDocument();
401    *   // set the XML elements and attributes into the result
402    *   contentHandler.endDocument();
403    * </pre>
404    *
405    * @param <T> the type of the class modeled by this Class object
406    * @param resultClass The class of the result, or null.
407    * If resultClass is null, a vendor specific Result implementation will be returned.
408    * The following classes are supported at a minimum:
409    * <pre>
410    *   javax.xml.transform.dom.DOMResult - returns a DOMResult
411    *   javax.xml.transform.sax.SAXResult - returns a SAXResult
412    *   javax.xml.transform.stax.StAXResult - returns a StAXResult
413    *   javax.xml.transform.stream.StreamResult - returns a StreamResult
414    * </pre>
415    * @return Returns a Result for setting the XML value.
416    * @throws SQLException if there is an error processing the XML value
417    *   or if this feature is not supported.
418    *   The getCause() method of the exception may provide a more detailed exception, for example,
419    *   if an XML parser exception occurs.
420    *   An exception is thrown if the state is not writable.
421    * @exception SQLFeatureNotSupportedException if the JDBC driver does not support
422    * this method
423    * @since 1.6
424    */
425   <T extends Result> T setResult(Class<T> resultClass) throws SQLException;
426 
427 }