1 /**

     2  * SQL-DK

     3  * Copyright © 2014 František Kučera (frantovo.cz)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, either version 3 of the License, or

     8  * (at your option) any later version.

     9  *

    10  * This program is distributed in the hope that it will be useful,

    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    13  * GNU General Public License for more details.

    14  *

    15  * You should have received a copy of the GNU General Public License

    16  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    17  */

    18 package info.globalcode.sql.dk.batch;

    19 

    20 import info.globalcode.sql.dk.Parameter;

    21 import info.globalcode.sql.dk.SQLCommand;

    22 import info.globalcode.sql.dk.SQLCommandNamed;

    23 import java.io.DataOutputStream;

    24 import java.io.IOException;

    25 import java.io.OutputStream;

    26 import static info.globalcode.sql.dk.batch.BatchConstants.*;

    27 import java.io.ByteArrayOutputStream;

    28 import java.sql.SQLException;

    29 import java.util.List;

    30 

    31 /**

    32  *

    33  * @author Ing. František Kučera (frantovo.cz)

    34  */

    35 public class BatchEncoder {

    36 

    37 	public int encode(SQLCommand sqlCommand, OutputStream out) throws BatchException {

    38 		try {

    39 			ByteArrayOutputStream bufferAOS = new ByteArrayOutputStream();

    40 			DataOutputStream buffer = new DataOutputStream(bufferAOS);

    41 

    42 			buffer.write(BATCH_HEADER);

    43 

    44 			if (sqlCommand instanceof SQLCommandNamed) {

    45 				sqlCommand = ((SQLCommandNamed) sqlCommand).getSQLCommandNumbered();

    46 			}

    47 

    48 			writeNextString(sqlCommand.getQuery(), buffer);

    49 

    50 			List<? extends Parameter> parameters = sqlCommand.getParameters();

    51 

    52 			buffer.writeInt(parameters.size());

    53 

    54 			for (Parameter p : parameters) {

    55 				buffer.writeInt(p.getType().getCode());

    56 				writeNextString((String) p.getValue(), buffer); // parameters are encoded before any preprocessing

    57 			}

    58 

    59 			buffer.flush();

    60 			bufferAOS.writeTo(out);

    61 			out.flush();

    62 			return bufferAOS.size();

    63 		} catch (IOException e) {

    64 			throw new BatchException("Unable to write SQL command: " + sqlCommand, e);

    65 		} catch (SQLException e) {

    66 			throw new BatchException("Unable to converd named SQL command to numbered: " + sqlCommand, e);

    67 		}

    68 	}

    69 

    70 	private void writeNextString(String s, DataOutputStream out) throws IOException {

    71 		byte[] bytes = toBytes(s);

    72 		out.writeInt(bytes.length);

    73 		out.write(bytes);

    74 	}

    75 

    76 	private static byte[] toBytes(String s) {

    77 		if (s == null) {

    78 			return new byte[]{};

    79 		} else {

    80 			return s.getBytes(CHARSET);

    81 		}

    82 	}

    83 }