1 /*

     2  * Copyright (c)  2017, 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

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

     7  * published by the Free Software Foundation.  Oracle designates this

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

     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

    18  * 2 along with this work; if not, write to the Free Software Foundation,

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

    20  *

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

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package java.sql2;

    26 

    27 import java.io.Reader;

    28 import java.io.Writer;

    29 import java.util.concurrent.CompletionStage;

    30 

    31 /**

    32  * A reference to a CHARACTER LARGE OBJECT in the attached database.

    33  *

    34  */

    35 public interface SqlClob extends AutoCloseable {

    36 

    37   /**

    38    * Return an {@link Operation} that will release the temporary resources

    39    * associated with this {@link SqlClob}.

    40    *

    41    * @return an {@link Operation} that will release the temporary resources

    42    * associated with this {@link SqlClob}.

    43    */

    44   public Operation<Void> closeOperation();

    45 

    46   @Override

    47   public default void close() {

    48     this.closeOperation().submit();

    49   }

    50 

    51   /**

    52    * Return a {@link Operation} that fetches the position of this {@link SqlClob}.

    53    * Position 0 is immediately before the first char in the {@link SqlClob}.

    54    * Position 1 is the first char in the {@link SqlClob}, etc. Position

    55    * {@link length()} is the last char in the {@link SqlClob}.

    56    *

    57    * Position is between 0 and length + 1.

    58    *

    59    * @return an {@link Operation} that returns the position of this {@link SqlClob}

    60    * @throws IllegalStateException if the {@link Connection} that created this

    61    * {@link SqlClob} is closed.;

    62    */

    63   public Operation<Long> getPositionOperation();

    64 

    65   /**

    66    * Get the position of this {@link SqlClob}. Position 0 is immediately before the

    67    * first char in the {@link SqlClob}. Position 1 is the first char in the

    68    * {@link SqlClob}, etc. Position {@link length()} is the last char in the SqlClob.

    69 

    70  Position is between 0 and length + 1.

    71 

    72  ISSUE: Should position be 1-based as SQL seems to do or 0-based as Java

    73  does?

    74    *

    75    * @return a future which value is the position of this {@link SqlClob}

    76    * @throws IllegalStateException if the {@link Connection} that created this

    77    * {@link SqlClob} is closed.

    78    */

    79   public default CompletionStage<Long> getPosition() {

    80     return getPositionOperation().submit().getCompletionStage();

    81   }

    82 

    83   /**

    84    * Return a {@link Operation} that fetches the length of this {@link SqlClob}.

    85    *

    86    * @return a {@link Operation} that returns the length of this {@link SqlClob}

    87    * @throws IllegalStateException if the {@link Connection} that created this

    88    * {@link SqlClob} is closed.

    89    */

    90   public Operation<Long> lengthOperation();

    91 

    92   /**

    93    * Get the length of this {@link SqlClob}.

    94    *

    95    * @return a {@link java.util.concurrent.Future} which value is the number of

    96    * chars in this {@link SqlClob}

    97    * @throws IllegalStateException if the {@link Connection} that created this

    98    * {@link SqlClob} is closed.

    99    */

   100   public default CompletionStage<Long> length() {

   101     return lengthOperation().submit().getCompletionStage();

   102   }

   103 

   104   /**

   105    * Return an {@link Operation} that sets the position of this {@link SqlClob}. If

   106    * {@code offset} exceeds the length of this {@link SqlClob} set position to the

   107    * length + 1 of this {@link SqlClob}, ie one past the last char.

   108    *

   109    * @param offset a non-negative number

   110    * @return a {@link Operation} that sets the position of this {@link SqlClob}

   111    * @throws IllegalArgumentException if {@code offset} is less than 0

   112    * @throws IllegalStateException if the {@link Connection} that created this

   113    * {@link SqlClob} is closed.

   114    */

   115   public Operation<Long> setPositionOperation(long offset);

   116 

   117   /**

   118    * Set the position of this {@link SqlClob}. If {@code offset} exceeds the length

   119    * of this {@link SqlClob} set position to the length + 1 of this {@link SqlClob},

   120    * ie one past the last char.

   121    *

   122    * @param offset the 1-based position to set

   123    * @return this {@link SqlClob}

   124    * @throws IllegalArgumentException if {@code offset} is less than 0

   125    * @throws IllegalStateException if the {@link Connection} that created this

   126    * {@link SqlClob} is closed.

   127    */

   128   public default SqlClob setPosition(long offset) {

   129     setPositionOperation(offset).submit();

   130     return this;

   131   }

   132 

   133   /**

   134    * Return an {@link Operation} to set the position to the beginning of the

   135    * next occurrence of the target after the position. If there is no such

   136    * occurrence set the position to 0.

   137    *

   138    * @param target a {@link SqlClob} created by the same {@link Connection}

   139    * containing the char sequence to search for

   140    * @return an {@link Operation} that locates {@code target} in this

   141    * {@link SqlClob}

   142    * @throws IllegalArgumentException if {@code target} was created by some

   143    * other {@link Connection}

   144    * @throws IllegalStateException if the {@link Connection} that created this

   145    * {@link SqlClob} is closed.

   146    */

   147   public Operation<Long> locateOperation(SqlClob target);

   148 

   149   /**

   150    * Set the position to the beginning of the next occurrence of the target

   151    * after the position. If there is no such occurrence set the position to 0.

   152    *

   153    * @param target the char sequence to search for

   154    * @return this {@link SqlClob}

   155    * @throws IllegalArgumentException if {@code target} was created by some

   156    * other {@link Connection}

   157    * @throws IllegalStateException if the {@link Connection} that created this

   158    * {@link SqlClob} is closed

   159    */

   160   public default SqlClob locate(SqlClob target) {

   161     locateOperation(target).submit();

   162     return this;

   163   }

   164 

   165   /**

   166    * Return an {@link Operation} to set the position to the beginning of the

   167    * next occurrence of the target after the position. If there is no such

   168    * occurrence set the position to 0.

   169    *

   170    * @param target the char sequence to search for. Not {@code null}. Captured.

   171    * @return an {@link Operation} that locates {@code target} in this

   172    * {@link SqlClob}

   173    * @throws IllegalStateException if the {@link Connection} that created this

   174    * {@link SqlClob} is closed.

   175    */

   176   public Operation<Long> locateOperation(CharSequence target);

   177 

   178   /**

   179    * Set the position to the beginning of the next occurrence of the target

   180    * after the position. If there is no such occurrence set the position to 0.

   181    *

   182    * @param target the char sequence to search for

   183    * @return this {@link SqlClob}

   184    * @throws IllegalStateException if the {@link Connection} that created this

   185    * {@link SqlClob} is closed.

   186    */

   187   public default SqlClob locate(CharSequence target) {

   188     locateOperation(target).submit();

   189     return this;

   190   }

   191 

   192   /**

   193    * Return an {@link Operation} that truncates this {@link SqlClob} so that the

   194    * current position is the end of the {@link SqlClob}. If the position is N, then

   195    * after trim() the length is N - 1. The position is still N. This will fail

   196    * if position is 0.

   197    *

   198    * @return an {@link Operation} that trims the length of this {@link SqlClob}

   199    * @throws IllegalStateException if the {@link Connection} that created this

   200    * {@link SqlClob} is closed or position is 0.

   201    */

   202   public Operation<Long> trimOperation();

   203 

   204   /**

   205    * Truncate this {@link SqlClob} so that the current position is the end of the

   206    * {@link SqlClob}. If the position is N, then after {@link trim()} the length is

   207    * N - 1. The position is still N. This will fail if position is 0.

   208    *

   209    * @return this {@link SqlClob}

   210    * @throws IllegalStateException if the {@link Connection} that created this

   211    * {@link SqlClob} is closed or position is 0.

   212    */

   213   public default SqlClob trim() {

   214     trimOperation().submit();

   215     return this;

   216   }

   217 

   218   /**

   219    * Returns a {@link Reader} for the characters in this {@link SqlClob}.

   220    * Characters are read starting at the current position. Each character read

   221    * advances the position by one.

   222    *

   223    * ISSUE: There is no character analog to

   224    * {@link java.nio.channels.AsynchronousByteChannel}. It is trivial to

   225    * construct a {@link java.io.Reader} from an

   226    * {@link java.nio.channels.AsynchronousByteChannel} however.

   227    *

   228    * @return a Reader for the characters in this SqlClob

   229    */

   230   public Reader getReader();

   231 

   232   /**

   233    * Returns a Writer for this {@link SqlClob}. Characters are written starting at

   234    * the current position. Each character written advances the position by one.

   235    *

   236    * ISSUE: There is no character analog to

   237    * {@link java.nio.channels.AsynchronousByteChannel}. It is trivial to

   238    * construct a {@link java.io.Writer} from an

   239    * {@link java.nio.channels.AsynchronousByteChannel} however.

   240    *

   241    * @return a Writer for the characters of this SqlClob

   242    */

   243   public Writer getWriter();

   244 

   245 }