SQLOutputImpl


1   /*
2    * @(#)SQLOutputImpl.java   1.5 04/05/05
3    *
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package javax.sql.rowset.serial;
9   
10  import java.sql.*;
11  import javax.sql.*;
12  import java.io.*;
13  import java.lang.String  ;
14  import java.math.*;
15  import java.util.Map  ;
16  import java.util.Vector  ;
17  
18  /**
19   * The output stream for writing the attributes of a 
20   * custom-mapped user-defined type (UDT) back to the database. 
21   * The driver uses this interface internally, and its
22   * methods are never directly invoked by an application programmer.
23   * <p>
24   * When an application calls the
25   * method <code>PreparedStatement.setObject</code>, the driver
26   * checks to see whether the value to be written is a UDT with
27   * a custom mapping.  If it is, there will be an entry in a
28   * type map containing the <code>Class</code> object for the
29   * class that implements <code>SQLData</code> for this UDT.
30   * If the value to be written is an instance of <code>SQLData</code>,
31   * the driver will create an instance of <code>SQLOutputImpl</code> 
32   * and pass it to the method <code>SQLData.writeSQL</code>.
33   * The method <code>writeSQL</code> in turn calls the
34   * appropriate <code>SQLOutputImpl.writeXXX</code> methods 
35   * to write data from the <code>SQLData</code> object to
36   * the <code>SQLOutputImpl</code> output stream as the 
37   * representation of an SQL user-defined type.
38   */
39  public class SQLOutputImpl implements SQLOutput {
40  
41      /**
42       * A reference to an existing vector that
43       * contains the attributes of a <code>Struct</code> object.
44       */
45      private Vector   attribs;
46  
47      /**
48       * The type map the driver supplies to a newly created
49       * <code>SQLOutputImpl</code> object.  This type map
50       * indicates the <code>SQLData</code> class whose
51       * <code>writeSQL</code> method will be called.  This
52       * method will in turn call the appropriate 
53       * <code>SQLOutputImpl/code> writer methods.
54       */
55      private Map   map;
56  
57      /**
58       * Creates a new <code>SQLOutputImpl</code> object
59       * initialized with the given vector of attributes and
60       * type map.  The driver will use the type map to determine
61       * which <code>SQLData.writeSQL</code> method to invoke.
62       * This method will then call the appropriate
63       * <code>SQLOutputImpl</code> writer methods in order and
64       * thereby write the attributes to the new output stream.
65       *
66       * @param attributes a <code>Vector</code> object containing the attributes of
67       *        the UDT to be mapped to one or more objects in the Java 
68       *        programming language
69       * 
70       * @param map a <code>java.util.Map</code> object containing zero or
71       *        more entries, with each entry consisting of 1) a <code>String</code>
72       *        giving the fully qualified name of a UDT and 2) the
73       *        <code>Class</code> object for the <code>SQLData</code> implementation
74       *        that defines how the UDT is to be mapped
75       * @throws SQLException if the <code>attributes</code> or the <code>map</code>
76       *        is a <code>null</code> value
77       */
78      public SQLOutputImpl(Vector  <?> attributes, Map  <String  ,?> map)
79      throws SQLException
80      {
81          if ((attributes == null) || (map == null)) {
82              throw new SQLException("Cannot instantiate a SQLOutputImpl " +
83              "instance with null parameters");
84          }        
85          this.attribs = attributes; 
86          this.map = map;
87      }
88  
89      //================================================================
90      // Methods for writing attributes to the stream of SQL data.
91      // These methods correspond to the column-accessor methods of
92      // java.sql.ResultSet.
93      //================================================================
94      
95      /**
96       * Writes a <code>String</code> in the Java programming language
97       * to this <code>SQLOutputImpl</code> object. The driver converts
98       * it to an SQL <code>CHAR</code>, <code>VARCHAR</code>, or 
99       * <code>LONGVARCHAR</code> before returning it to the database.
100      *
101      * @param x the value to pass to the database
102      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
103      *        use by a <code>SQLData</code> object attempting to write the attribute
104      *        values of a UDT to the database.
105      */
106     public void writeString(String   x) throws SQLException {
107         //System.out.println("Adding :"+x);
108         attribs.add(x);
109     }
110 
111     /**
112      * Writes a <code>boolean</code> in the Java programming language
113      * to this <code>SQLOutputImpl</code> object. The driver converts
114      * it to an SQL <code>BIT</code> before returning it to the database.
115      *
116      * @param x the value to pass to the database     
117      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
118      *        use by a <code>SQLData</code> object attempting to write the attribute
119      *        values of a UDT to the database.
120      */
121     public void writeBoolean(boolean x) throws SQLException {
122         attribs.add(new Boolean  (x));
123     }
124 
125     /**
126      * Writes a <code>byte</code> in the Java programming language
127      * to this <code>SQLOutputImpl</code> object. The driver converts
128      * it to an SQL <code>BIT</code> before returning it to the database.
129      *
130      * @param x the value to pass to the database
131      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
132      *        use by a <code>SQLData</code> object attempting to write the attribute
133      *        values of a UDT to the database.
134      */
135     public void writeByte(byte x) throws SQLException {
136         attribs.add(new Byte  (x));
137     }
138 
139     /**
140      * Writes a <code>short</code> in the Java programming language
141      * to this <code>SQLOutputImpl</code> object. The driver converts
142      * it to an SQL <code>SMALLINT</code> before returning it to the database.
143      *
144      * @param x the value to pass to the database     
145      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
146      *        use by a <code>SQLData</code> object attempting to write the attribute
147      *        values of a UDT to the database.
148      */
149     public void writeShort(short x) throws SQLException {
150         attribs.add(new Short  (x));
151     }
152 
153     /**
154      * Writes an <code>int</code> in the Java programming language
155      * to this <code>SQLOutputImpl</code> object. The driver converts
156      * it to an SQL <code>INTEGER</code> before returning it to the database.
157      *
158      * @param x the value to pass to the database
159      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
160      *        use by a <code>SQLData</code> object attempting to write the attribute
161      *        values of a UDT to the database.
162      */
163     public void writeInt(int x) throws SQLException {
164         attribs.add(new Integer  (x));
165     }
166 
167     /**
168      * Writes a <code>long</code> in the Java programming language
169      * to this <code>SQLOutputImpl</code> object. The driver converts
170      * it to an SQL <code>BIGINT</code> before returning it to the database.
171      *
172      * @param x the value to pass to the database
173      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
174      *        use by a <code>SQLData</code> object attempting to write the attribute
175      *        values of a UDT to the database.
176      */
177     public void writeLong(long x) throws SQLException {
178         attribs.add(new Long  (x));
179     }
180 
181     /**
182      * Writes a <code>float</code> in the Java programming language
183      * to this <code><code>SQLOutputImpl</code></code> object. The driver converts
184      * it to an SQL <code>REAL</code> before returning it to the database.
185      *
186      * @param x the value to pass to the database
187      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
188      *        use by a <code>SQLData</code> object attempting to write the attribute
189      *        values of a UDT to the database.
190      */
191     public void writeFloat(float x) throws SQLException {
192         attribs.add(new Float  (x));
193     }
194 
195     /**
196      * Writes a <code>double</code> in the Java programming language
197      * to this <code>SQLOutputImpl</code> object. The driver converts
198      * it to an SQL <code>DOUBLE</code> before returning it to the database.
199      *
200      * @param x the value to pass to the database
201      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
202      *        use by a <code>SQLData</code> object attempting to write the attribute
203      *        values of a UDT to the database.
204      */
205     public void writeDouble(double x) throws SQLException{
206         attribs.add(new Double  (x));
207     }
208 
209     /**
210      * Writes a <code>java.math.BigDecimal</code> object in the Java programming
211      * language to this <code>SQLOutputImpl</code> object. The driver converts
212      * it to an SQL <code>NUMERIC</code> before returning it to the database.
213      *
214      * @param x the value to pass to the database    
215      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
216      *        use by a <code>SQLData</code> object attempting to write the attribute
217      *        values of a UDT to the database.     
218      */
219     public void writeBigDecimal(java.math.BigDecimal   x) throws SQLException{
220         attribs.add(x);
221     }
222 
223     /**
224      * Writes an array of <code>bytes</code> in the Java programming language
225      * to this <code>SQLOutputImpl</code> object. The driver converts
226      * it to an SQL <code>VARBINARY</code> or <code>LONGVARBINARY</code>
227      * before returning it to the database.
228      *
229      * @param x the value to pass to the database  
230      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
231      *        use by a <code>SQLData</code> object attempting to write the attribute
232      *        values of a UDT to the database.
233      */
234     public void writeBytes(byte[] x) throws SQLException {
235         attribs.add(x);
236     }
237 
238     /**
239      * Writes a <code>java.sql.Date</code> object in the Java programming
240      * language to this <code>SQLOutputImpl</code> object. The driver converts
241      * it to an SQL <code>DATE</code> before returning it to the database.
242      *
243      * @param x the value to pass to the database          
244      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
245      *        use by a <code>SQLData</code> object attempting to write the attribute
246      *        values of a UDT to the database.
247      */
248     public void writeDate(java.sql.Date   x) throws SQLException {
249         attribs.add(x);
250     }
251 
252     /**
253      * Writes a <code>java.sql.Time</code> object in the Java programming
254      * language to this <code>SQLOutputImpl</code> object. The driver converts
255      * it to an SQL <code>TIME</code> before returning it to the database.
256      *
257      * @param x the value to pass to the database
258      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
259      *        use by a <code>SQLData</code> object attempting to write the attribute
260      *        values of a UDT to the database.
261      */
262     public void writeTime(java.sql.Time   x) throws SQLException {
263         attribs.add(x);
264     }
265 
266     /**
267      * Writes a <code>java.sql.Timestamp</code> object in the Java programming
268      * language to this <code>SQLOutputImpl</code> object. The driver converts
269      * it to an SQL <code>TIMESTAMP</code> before returning it to the database.
270      *
271      * @param x the value to pass to the database
272      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
273      *        use by a <code>SQLData</code> object attempting to write the attribute
274      *        values of a UDT to the database.
275      */
276     public void writeTimestamp(java.sql.Timestamp   x) throws SQLException {
277         attribs.add(x);
278     }
279 
280     /**
281      * Writes a stream of Unicode characters to this
282      * <code>SQLOutputImpl</code> object. The driver will do any necessary
283      * conversion from Unicode to the database <code>CHAR</code> format.
284      *
285      * @param x the value to pass to the database           
286      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
287      *        use by a <code>SQLData</code> object attempting to write the attribute
288      *        values of a UDT to the database.
289      */
290     public void writeCharacterStream(java.io.Reader   x) throws SQLException {
291          BufferedReader bufReader = new BufferedReader(x);
292          try {
293              int i;
294              while( (i = bufReader.read()) != -1 ) {
295                 char ch = (char)i;
296         StringBuffer   strBuf = new StringBuffer  ();
297         strBuf.append(ch);
298         
299         String   str = new String  (strBuf);                
300                 String   strLine = bufReader.readLine();
301                 
302                 writeString(str.concat(strLine));
303              }   
304          } catch(IOException ioe) {
305          
306          }
307     }
308 
309     /**
310      * Writes a stream of ASCII characters to this
311      * <code>SQLOutputImpl</code> object. The driver will do any necessary
312      * conversion from ASCII to the database <code>CHAR</code> format.
313      *
314      * @param x the value to pass to the database
315      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
316      *        use by a <code>SQLData</code> object attempting to write the attribute
317      *        values of a UDT to the database.
318      */
319     public void writeAsciiStream(java.io.InputStream   x) throws SQLException {
320          BufferedReader bufReader = new BufferedReader(new InputStreamReader(x));
321          try {
322                int i;
323                while( (i=bufReader.read()) != -1 ) {
324                 char ch = (char)i;
325                
326         StringBuffer   strBuf = new StringBuffer  ();
327         strBuf.append(ch);
328         
329         String   str = new String  (strBuf);                
330                 String   strLine = bufReader.readLine();
331                 
332                 writeString(str.concat(strLine));
333             }
334           }catch(IOException ioe) {
335             throw new SQLException(ioe.getMessage());
336         }
337     }
338 
339     /**
340      * Writes a stream of uninterpreted bytes to this <code>SQLOutputImpl</code>
341      * object.
342      *
343      * @param x the value to pass to the database
344      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
345      *        use by a <code>SQLData</code> object attempting to write the attribute
346      *        values of a UDT to the database.
347      */
348     public void writeBinaryStream(java.io.InputStream   x) throws SQLException {
349          BufferedReader bufReader = new BufferedReader(new InputStreamReader(x));
350          try {
351                int i;
352              while( (i=bufReader.read()) != -1 ) {
353                 char ch = (char)i;
354                
355         StringBuffer   strBuf = new StringBuffer  ();
356         strBuf.append(ch);
357         
358         String   str = new String  (strBuf);                
359                 String   strLine = bufReader.readLine();
360                 
361                 writeString(str.concat(strLine));
362              }
363         } catch(IOException ioe) {
364             throw new SQLException(ioe.getMessage());
365         }
366     }
367     
368     //================================================================
369     // Methods for writing items of SQL user-defined types to the stream.
370     // These methods pass objects to the database as values of SQL
371     // Structured Types, Distinct Types, Constructed Types, and Locator
372     // Types.  They decompose the Java object(s) and write leaf data
373     // items using the methods above.
374     //================================================================
375 
376     /**
377      * Writes to the stream the data contained in the given 
378      * <code>SQLData</code> object.
379      * When the <code>SQLData</code> object is <code>null</code>, this
380      * method writes an SQL <code>NULL</code> to the stream.  
381      * Otherwise, it calls the <code>SQLData.writeSQL</code>
382      * method of the given object, which 
383      * writes the object's attributes to the stream.
384      * <P>
385      * The implementation of the method <code>SQLData.writeSQ</code>
386      * calls the appropriate <code>SQLOutputImpl.writeXXX</code> method(s)
387      * for writing each of the object's attributes in order.
388      * The attributes must be read from an <code>SQLInput</code>
389      * input stream and written to an <code>SQLOutputImpl</code>
390      * output stream in the same order in which they were
391      * listed in the SQL definition of the user-defined type.
392      * 
393      * @param x the object representing data of an SQL structured or
394      *          distinct type
395      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
396      *        use by a <code>SQLData</code> object attempting to write the attribute
397      *        values of a UDT to the database.
398      */
399     public void writeObject(SQLData x) throws SQLException {
400         
401         /*
402          * Except for the types that are passed as objects
403          * this seems to be the only way for an object to
404          * get a null value for a field in a structure.
405          *
406          * Note: this means that the class defining SQLData 
407          * will need to track if a field is SQL null for itself
408          */
409         if (x == null) {
410             attribs.add(x);
411             return;
412         }
413         
414         /* 
415          * We have to write out a SerialStruct that contains
416          * the name of this class otherwise we don't know
417          * what to re-instantiate during readSQL()
418          */
419         attribs.add(new SerialStruct  ((SQLData)x, map));
420     }
421 
422     /**
423      * Writes a <code>Ref</code> object in the Java programming language
424      * to this <code>SQLOutputImpl</code> object.  The driver converts
425      * it to a serializable <code>SerialRef</code> SQL <code>REF</code> value 
426      * before returning it to the database.
427      *
428      * @param x an object representing an SQL <code>REF</code> value
429      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
430      *        use by a <code>SQLData</code> object attempting to write the attribute
431      *        values of a UDT to the database.
432      */
433     public void writeRef(Ref x) throws SQLException {
434         if (x == null) {
435             attribs.add(x);
436             return;
437         }
438         attribs.add(new SerialRef  (x));
439     }
440 
441     /**
442      * Writes a <code>Blob</code> object in the Java programming language
443      * to this <code>SQLOutputImpl</code> object.  The driver converts
444      * it to a serializable <code>SerialBlob</code> SQL <code>BLOB</code> value 
445      * before returning it to the database.
446      *
447      * @param x an object representing an SQL <code>BLOB</code> value
448      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
449      *        use by a <code>SQLData</code> object attempting to write the attribute
450      *        values of a UDT to the database.
451      */
452     public void writeBlob(Blob x) throws SQLException {
453         if (x == null) {
454             attribs.add(x);
455             return;
456         }
457         attribs.add(new SerialBlob  (x));
458     }
459     
460     /**
461      * Writes a <code>Clob</code> object in the Java programming language
462      * to this <code>SQLOutputImpl</code> object.  The driver converts
463      * it to a serializable <code>SerialClob</code> SQL <code>CLOB</code> value 
464      * before returning it to the database.
465      *
466      * @param x an object representing an SQL <code>CLOB</code> value
467      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
468      *        use by a <code>SQLData</code> object attempting to write the attribute
469      *        values of a UDT to the database.
470      */
471     public void writeClob(Clob x) throws SQLException {
472         if (x == null) {
473             attribs.add(x);
474             return;
475         }
476         attribs.add(new SerialClob  (x));
477     }
478 
479     /**
480      * Writes a <code>Struct</code> object in the Java
481      * programming language to this <code>SQLOutputImpl</code>
482      * object. The driver converts this value to an SQL structured type
483      * before returning it to the database.
484      * <P>
485      * This method should be used when an SQL structured type has been
486      * mapped to a <code>Struct</code> object in the Java programming
487      * language (the standard mapping).  The method 
488      * <code>writeObject</code> should be used if an SQL structured type
489      * has been custom mapped to a class in the Java programming language.
490      *
491      * @param x an object representing the attributes of an SQL structured type          
492      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
493      *        use by a <code>SQLData</code> object attempting to write the attribute
494      *        values of a UDT to the database.
495      */
496     public void writeStruct(Struct x) throws SQLException {
497         SerialStruct   s = new SerialStruct  (x,map);;
498         attribs.add(s);        
499     }
500     
501     /**
502      * Writes an <code>Array</code> object in the Java
503      * programming language to this <code>SQLOutputImpl</code>
504      * object. The driver converts this value to a serializable 
505      * <code>SerialArray</code> SQL <code>ARRAY</code>
506      * value before returning it to the database.
507      *
508      * @param x an object representing an SQL <code>ARRAY</code> value
509      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
510      *        use by a <code>SQLData</code> object attempting to write the attribute
511      *        values of a UDT to the database.
512      */
513     public void writeArray(Array x) throws SQLException {
514         if (x == null) {
515             attribs.add(x);
516             return;
517         }
518         attribs.add(new SerialArray  (x, map));
519     }
520 
521     /**
522      * Writes an <code>java.sql.Type.DATALINK</code> object in the Java 
523      * programming language to this <code>SQLOutputImpl</code> object. The
524      * driver converts this value to a serializable <code>SerialDatalink</code>
525      * SQL <code>DATALINK</code> value before return it to the database.
526      *     
527      * @param url an object representing a SQL <code>DATALINK</code> value
528      * @throws SQLException if the <code>SQLOutputImpl</code> object is in
529      *        use by a <code>SQLData</code> object attempting to write the attribute
530      *        values of a UDT to the database.
531      */
532     public void writeURL(java.net.URL   url) throws SQLException {
533         if (url == null) {
534             attribs.add(url);
535             return;
536         }
537         attribs.add(new SerialDatalink  (url));
538         
539     }
540 }
541 
542 
543 
544 
545 
546
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