BlobJDBCAdapter xref

View Javadoc

    1   /***
    2    *
    3    * Copyright 2004 Hiram Chirino
    4    *
    5    * Licensed under the Apache License, Version 2.0 (the "License");
    6    * you may not use this file except in compliance with the License.
    7    * You may obtain a copy of the License at
    8    *
    9    * http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   **/
    18  package org.codehaus.activemq.store.jdbc.adapter;
    19
    20  import java.io.ByteArrayOutputStream;
    21  import java.io.IOException;
    22  import java.io.InputStream;
    23  import java.io.OutputStream;
    24  import java.sql.Blob;
    25  import java.sql.Connection;
    26  import java.sql.PreparedStatement;
    27  import java.sql.ResultSet;
    28  import java.sql.SQLException;
    29
    30  import javax.jms.JMSException;
    31
    32  import org.codehaus.activemq.store.jdbc.StatementProvider;
    33
    34
    35  /***
    36   * This JDBCAdapter inserts and extracts BLOB data using the
    37   * getBlob()/setBlob() operations.  This is a little more involved
    38   * since to insert a blob you have to:
    39   *
    40   *  1: insert empty blob.
    41   *  2: select the blob
    42   *  3: finally update the blob with data value.
    43   *
    44   * The databases/JDBC drivers that use this adapter are:
    45   * <ul>
    46   * <li></li>
    47   * </ul>
    48   *
    49   * @version $Revision: 1.1 $
    50   */
    51  public class BlobJDBCAdapter extends DefaultJDBCAdapter {
    52
    53      public BlobJDBCAdapter() {
    54          super();
    55      }
    56
    57      public BlobJDBCAdapter(StatementProvider provider) {
    58          super(provider);
    59      }
    60
    61      public void doAddMessage(Connection c, long seq, String messageID, String destinationName, byte[] data) throws SQLException,
    62              JMSException {
    63          PreparedStatement s = null;
    64          ResultSet rs = null;
    65          try {
    66
    67              // Add the Blob record.
    68              s = c.prepareStatement(statementProvider.getAddMessageStatment());
    69              s.setLong(1, seq);
    70              s.setString(2, destinationName);
    71              s.setString(3, messageID);
    72              s.setString(4, " ");
    73
    74              if (s.executeUpdate() != 1)
    75                  throw new JMSException("Failed to broker message: " + messageID
    76                          + " in container.");
    77              s.close();
    78
    79              // Select the blob record so that we can update it.
    80              s = c.prepareStatement(statementProvider.getFindMessageStatment());
    81              s.setLong(1, seq);
    82              rs = s.executeQuery();
    83              if (!rs.next())
    84                  throw new JMSException("Failed to broker message: " + messageID
    85                          + " in container.");
    86
    87              // Update the blob
    88              Blob blob = rs.getBlob(1);
    89              OutputStream stream = blob.setBinaryStream(data.length);
    90              stream.write(data);
    91              stream.close();
    92              s.close();
    93
    94              // Update the row with the updated blob
    95              s = c.prepareStatement(statementProvider.getUpdateMessageStatment());
    96              s.setBlob(1, blob);
    97              s.setLong(2, seq);
    98
    99          } catch (IOException e) {
    100             throw (SQLException) new SQLException("BLOB could not be updated: "
    101                     + e).initCause(e);
    102         } finally {
    103             try {
    104                 rs.close();
    105             } catch (Throwable e) {
    106             }
    107             try {
    108                 s.close();
    109             } catch (Throwable e) {
    110             }
    111         }
    112     }
    113
    114     public byte[] doGetMessage(Connection c, long seq) throws SQLException {
    115 	    PreparedStatement s=null; ResultSet rs=null;
    116 	    try {
    117
    118 	        s = c.prepareStatement(statementProvider.getFindMessageStatment());
    119 	        s.setLong(1, seq);
    120 	        rs = s.executeQuery();
    121
    122 	        if( !rs.next() )
    123 	            return null;
    124 	        Blob blob = rs.getBlob(1);
    125 	        InputStream is = blob.getBinaryStream();
    126
    127 	        ByteArrayOutputStream os = new ByteArrayOutputStream((int)blob.length());
    128 	        int ch;
    129 	        while( (ch=is.read())>= 0 ) {
    130 	            os.write(ch);
    131 	        }
    132 	        is.close();
    133 	        os.close();
    134
    135 	        return os.toByteArray();
    136
    137 	    } catch (IOException e) {
    138             throw (SQLException) new SQLException("BLOB could not be updated: "
    139                     + e).initCause(e);
    140         } finally {
    141 	        try { rs.close(); } catch (Throwable e) {}
    142 	        try { s.close(); } catch (Throwable e) {}
    143 	    }
    144     }
    145
    146 }