java/sql-dk/src/main/java/info/globalcode/sql/dk/batch/BatchEncoder.java
branchv_0
changeset 238 4a1864c3e867
parent 147 4a704c1669f4
child 250 aae5009bd0af
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/sql-dk/src/main/java/info/globalcode/sql/dk/batch/BatchEncoder.java	Mon Mar 04 20:15:24 2019 +0100
@@ -0,0 +1,83 @@
+/**
+ * SQL-DK
+ * Copyright © 2014 František Kučera (frantovo.cz)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package info.globalcode.sql.dk.batch;
+
+import info.globalcode.sql.dk.Parameter;
+import info.globalcode.sql.dk.SQLCommand;
+import info.globalcode.sql.dk.SQLCommandNamed;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import static info.globalcode.sql.dk.batch.BatchConstants.*;
+import java.io.ByteArrayOutputStream;
+import java.sql.SQLException;
+import java.util.List;
+
+/**
+ *
+ * @author Ing. František Kučera (frantovo.cz)
+ */
+public class BatchEncoder {
+
+	public int encode(SQLCommand sqlCommand, OutputStream out) throws BatchException {
+		try {
+			ByteArrayOutputStream bufferAOS = new ByteArrayOutputStream();
+			DataOutputStream buffer = new DataOutputStream(bufferAOS);
+
+			buffer.write(BATCH_HEADER);
+
+			if (sqlCommand instanceof SQLCommandNamed) {
+				sqlCommand = ((SQLCommandNamed) sqlCommand).getSQLCommandNumbered();
+			}
+
+			writeNextString(sqlCommand.getQuery(), buffer);
+
+			List<? extends Parameter> parameters = sqlCommand.getParameters();
+
+			buffer.writeInt(parameters.size());
+
+			for (Parameter p : parameters) {
+				buffer.writeInt(p.getType().getCode());
+				writeNextString((String) p.getValue(), buffer); // parameters are encoded before any preprocessing
+			}
+
+			buffer.flush();
+			bufferAOS.writeTo(out);
+			out.flush();
+			return bufferAOS.size();
+		} catch (IOException e) {
+			throw new BatchException("Unable to write SQL command: " + sqlCommand, e);
+		} catch (SQLException e) {
+			throw new BatchException("Unable to converd named SQL command to numbered: " + sqlCommand, e);
+		}
+	}
+
+	private void writeNextString(String s, DataOutputStream out) throws IOException {
+		byte[] bytes = toBytes(s);
+		out.writeInt(bytes.length);
+		out.write(bytes);
+	}
+
+	private static byte[] toBytes(String s) {
+		if (s == null) {
+			return new byte[]{};
+		} else {
+			return s.getBytes(CHARSET);
+		}
+	}
+}