jdbcDriver


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30  
31  
32  package org.hsqldb;
33  
34  import java.sql.Connection  ;
35  import java.sql.Driver  ;
36  import java.sql.DriverManager  ;
37  import java.sql.DriverPropertyInfo  ;
38  import java.sql.SQLException  ;
39  import java.util.Properties  ;
40  
41  import org.hsqldb.jdbc.jdbcConnection;
42  import org.hsqldb.persist.HsqlDatabaseProperties;
43  import org.hsqldb.persist.HsqlProperties;
44  
45  // fredt@users 20011220 - patch 1.7.0 by fredt
46  // new version numbering scheme
47  // fredt@users 20020320 - patch 1.7.0 - JDBC 2 support and error trapping
48  // JDBC 2 methods can now be called from jdk 1.1.x - see javadoc comments
49  // fredt@users 20030528 - patch 1.7.2 suggested by Gerhard Hiller - support for properties in URL
50  
51  /**
52   * The following comments are from the http://ldbc.sourceforge.net project.
53   * These are the issues with HSQLDB JDBC implementation that are currently
54   * not resolved. Other issues stated there have been resolved in 1.8.0.
55   *
56   * Time format error: the following statement should work, but throws an exception:
57   * CREATE TABLE Test ( ID INT , Current DATETIME )
58   * insert into test values(1,'2002-01-01 0:0:0.0')
59   * This works:
60   * insert into test values(1,'2002-01-01 00:00:00.0')
61   *
62   * ABS(4) returns data type DECIMAL, should return data type INTEGER
63   *
64   * Should throw a exception if PreparedStatement.setObject(1,null) is called.
65   * See also JDBC API Tutorial and Reference, Second Edition,
66   * page 544, 24.1.5 Sending JDBC NULL as an IN parameter
67   *
68   * Statement / PreparedStatement setMaxFieldSize is ignored.
69   *
70   * The database should support at least Connection.TRANSACTION_READ_COMMITTED.
71   * Currently, only TRANSACTION_READ_UNCOMMITTED is supported.
72   *
73   * Statement.getQueryTimeout doesn't return the value set before.
74   *
75   * When autocommit is on, executing a query on a statement is
76   * supposed to close the old resultset. This is not implemented.
77   */
78  
79  /**
80   *  Each JDBC driver must supply a class that implements the Driver
81   *  interface. <p>
82   *
83   *  The Java SQL framework allows for multiple database drivers. <p>
84   *
85   *  The DriverManager will try to load as many drivers as it can find and
86   *  then for any given connection request, it will ask each driver in turn
87   *  to try to connect to the target URL. <p>
88   *
89   *  The application developer will normally not need
90   *  to call any function of the Driver directly. All required calls are made
91   *  by the DriverManager. <p>
92   *
93   * <!-- start release-specific documentation -->
94   * <div class="ReleaseSpecificDocumentation">
95   * <h3>HSQLDB-Specific Information:</h3> <p>
96   *  When the HSQL Database Engine Driver class is loaded, it creates an
97   *  instance of itself and register it with the DriverManager. This means
98   *  that a user can load and register the HSQL Database Engine driver by
99   *  calling <pre>
100  * <code>Class.forName("org.hsqldb.jdbcDriver")</code> </pre> For more
101  *  information about how to connect to a HSQL Database Engine database,
102  *  please see jdbcConnection. </font><p>
103  *
104  *  As of version 1.7.0 all JDBC 2 methods can be
105  *  called with jdk 1.1.x. Some of these method calls require int values
106  *  that are defined in JDBC 2 version of ResultSet. These values are
107  *  defined in the jdbcResultSet class when it is compiled with jdk 1.1.x.
108  *  When using the JDBC 2 methods that require those values as parameters or
109  *  return one of those values, refer to them as follows: (The code will not
110  *  be compatible with other JDBC 2 driver, which require ResultSet to be
111  *  used instead of jdbcResultSet) (fredt@users)<p>
112  * </div> <!-- end release-specific documentation -->
113  *
114  *  jdbcResultSet.FETCH_FORWARD<br>
115  *  jdbcResultSet.TYPE_FORWARD_ONLY<br>
116  *  jdbcResultSet TYPE_SCROLL_INSENSITIVE<br>
117  *  jdbcResultSet.CONCUR_READ_ONLY</font><p>
118  *
119  *
120  * @see  jdbcConnection
121  */
122 public class jdbcDriver implements Driver   {
123 
124     /**
125      *  Attempts to make a database connection to the given URL. The driver
126      *  returns "null" if it realizes it is the wrong kind of driver to
127      *  connect to the given URL. This will be common, as when the JDBC
128      *  driver manager is asked to connect to a given URL it passes the URL
129      *  to each loaded driver in turn.<p>
130      *
131      *  The driver raises a SQLException if it is the right driver to
132      *  connect to the given URL, but has trouble connecting to the
133      *  database.<p>
134      *
135      *  The java.util.Properties argument can be used to passed arbitrary
136      *  string tag/value pairs as connection arguments.<p>
137      *
138      * <!-- start release-specific documentation -->
139      * <div class="ReleaseSpecificDocumentation">
140      * <h3>HSQLDB-Specific Information:</h3> <p>
141      *  For HSQL Database Engine, at least "user" and
142      *  "password" properties must be included in the Properties. From
143      *  version 1.7.1 two optional properties are supported:<p>
144      *  <code>get_column_name</code> if set to false, a
145      *  ResultSetMetaData.getColumnName() call will return the user defined
146      *  label instead of the column name.
147      *  <code>strict_md</code> if set to true, some ResultSetMetaData methods
148      *  return more strict values for compatibility reasons.
149      * </div> <!-- end release-specific documentation -->
150      *
151      * @param  url the URL of the database to which to connect
152      * @param  info a list of arbitrary string tag/value pairs as connection
153      *      arguments. Normally at least a "user" and "password" property
154      *      should be included.
155      * @return  a <code>Connection</code> object that represents a
156      *      connection to the URL
157      * @exception  SQLException if a database access error occurs
158      */
159     public Connection   connect(String   url,
160                               Properties   info) throws SQLException   {
161         return getConnection(url, info);
162     }
163 
164     public static Connection   getConnection(String   url,
165                                            Properties   info)
166                                            throws SQLException   {
167 
168         HsqlProperties props = DatabaseURL.parseURL(url, true);
169 
170         if (props == null) {
171 
172             // supposed to be an HSQLDB driver url but has errors
173             throw new SQLException  (
174                 Trace.getMessage(Trace.INVALID_JDBC_ARGUMENT));
175         } else if (props.isEmpty()) {
176 
177             // is not an HSQLDB driver url
178             return null;
179         }
180 
181         props.addProperties(info);
182 
183         return new jdbcConnection(props);
184     }
185 
186     /**
187      *  Returns true if the driver thinks that it can open a connection to
188      *  the given URL. Typically drivers will return true if they understand
189      *  the subprotocol specified in the URL and false if they don't.
190      *
191      * @param  url the URL of the database
192      * @return  true if this driver can connect to the given URL
193      */
194 
195     // fredt@users - patch 1.7.0 - allow mixedcase url's
196     public boolean acceptsURL(String   url) {
197 
198         return url != null
199                && url.regionMatches(true, 0, DatabaseURL.S_URL_PREFIX, 0,
200                                     DatabaseURL.S_URL_PREFIX.length());
201     }
202 
203     /**
204      *  Gets information about the possible properties for this driver. <p>
205      *
206      *  The getPropertyInfo method is intended to allow a generic GUI tool
207      *  to discover what properties it should prompt a human for in order to
208      *  get enough information to connect to a database. Note that depending
209      *  on the values the human has supplied so far, additional values may
210      *  become necessary, so it may be necessary to iterate though several
211      *  calls to getPropertyInfo.<p>
212      *
213      * <!-- start release-specific documentation -->
214      * <div class="ReleaseSpecificDocumentation">
215      * <h3>HSQLDB-Specific Information:</h3> <p>
216      * HSQLDB 1.7.2 uses the values submitted in info to set the value for
217      * each DriverPropertyInfo object returned. It does not use the default
218      * value that it would use for the property if the value is null.
219      * </div> <!-- end release-specific documentation -->
220      *
221      * @param  url the URL of the database to which to connect
222      * @param  info a proposed list of tag/value pairs that will be sent on
223      *      connect open
224      * @return  an array of DriverPropertyInfo objects describing possible
225      *      properties. This array may be an empty array if no properties
226      *      are required.
227      */
228     public DriverPropertyInfo  [] getPropertyInfo(String   url, Properties   info) {
229 
230         String  []             choices = new String  [] {
231             "true", "false"
232         };
233         DriverPropertyInfo  [] pinfo   = new DriverPropertyInfo  [6];
234         DriverPropertyInfo     p;
235 
236         p          = new DriverPropertyInfo  ("user", null);
237         p.value    = info.getProperty("user");
238         p.required = true;
239         pinfo[0]   = p;
240         p          = new DriverPropertyInfo  ("password", null);
241         p.value    = info.getProperty("password");
242         p.required = true;
243         pinfo[1]   = p;
244         p          = new DriverPropertyInfo  ("get_column_name", null);
245         p.value    = info.getProperty("get_column_name", "true");
246         p.required = false;
247         p.choices  = choices;
248         pinfo[2]   = p;
249         p          = new DriverPropertyInfo  ("ifexists", null);
250         p.value    = info.getProperty("ifexists");
251         p.required = false;
252         p.choices  = choices;
253         pinfo[3]   = p;
254         p          = new DriverPropertyInfo  ("default_schema", null);
255         p.value    = info.getProperty("default_schema");
256         p.required = false;
257         p.choices  = choices;
258         pinfo[4]   = p;
259         p          = new DriverPropertyInfo  ("shutdown", null);
260         p.value    = info.getProperty("shutdown");
261         p.required = false;
262         p.choices  = choices;
263         pinfo[5]   = p;
264 
265         return pinfo;
266     }
267 
268     /**
269      *  Gets the driver's major version number.
270      *
271      * @return  this driver's major version number
272      */
273     public int getMajorVersion() {
274         return HsqlDatabaseProperties.MAJOR;
275     }
276 
277     /**
278      *  Gets the driver's minor version number.
279      *
280      * @return  this driver's minor version number
281      */
282     public int getMinorVersion() {
283         return HsqlDatabaseProperties.MINOR;
284     }
285 
286     /**
287      *  Reports whether this driver is a genuine JDBC COMPLIANT<sup><font
288      *  size=-2>TM</font> </sup> driver. A driver may only report true here
289      *  if it passes the JDBC compliance tests; otherwise it is required to
290      *  return false. JDBC compliance requires full support for the JDBC API
291      *  and full support for SQL 92 Entry Level. It is expected that JDBC
292      *  compliant drivers will be available for all the major commercial
293      *  databases. <p>
294      *
295      * <!-- start release-specific documentation -->
296      * <div class="ReleaseSpecificDocumentation">
297      * <h3>HSQLDB-Specific Information:</h3> <p>
298      *  HSQL Database Engine currently does not yet
299      *  support all required SQL 92 Entry Level functionality and thus
300      *  returns false. It looks like other drivers return true but do not
301      *  support all features.<p>
302      * </div> <!-- end release-specific documentation -->
303      *
304      *  This method is not intended to encourage the development of non-JDBC
305      *  compliant drivers, but is a recognition of the fact that some
306      *  vendors are interested in using the JDBC API and framework for
307      *  lightweight databases that do not support full database
308      *  functionality, or for special databases such as document information
309      *  retrieval where a SQL implementation may not be feasible.
310      *
311      * @return  Description of the Return Value
312      */
313     public boolean jdbcCompliant() {
314 
315 /** @todo fredt - we should aim to be able to report true */
316         return false;
317     }
318 
319     static {
320         try {
321             DriverManager.registerDriver(new jdbcDriver());
322         } catch (Exception   e) {}
323     }
324 }
325
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