1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/java/sql-dk/src/info/globalcode/sql/dk/batch/BatchDecoder.java Wed Jan 08 19:18:52 2014 +0100
1.3 @@ -0,0 +1,110 @@
1.4 +/**
1.5 + * SQL-DK
1.6 + * Copyright © 2014 František Kučera (frantovo.cz)
1.7 + *
1.8 + * This program is free software: you can redistribute it and/or modify
1.9 + * it under the terms of the GNU General Public License as published by
1.10 + * the Free Software Foundation, either version 3 of the License, or
1.11 + * (at your option) any later version.
1.12 + *
1.13 + * This program is distributed in the hope that it will be useful,
1.14 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.15 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.16 + * GNU General Public License for more details.
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License
1.19 + * along with this program. If not, see <http://www.gnu.org/licenses/>.
1.20 + */
1.21 +package info.globalcode.sql.dk.batch;
1.22 +
1.23 +import info.globalcode.sql.dk.Parameter;
1.24 +import info.globalcode.sql.dk.SQLCommand;
1.25 +import info.globalcode.sql.dk.SQLCommandNumbered;
1.26 +import java.io.DataInputStream;
1.27 +import java.io.InputStream;
1.28 +import static info.globalcode.sql.dk.batch.BatchConstants.*;
1.29 +import static info.globalcode.sql.dk.Functions.toHex;
1.30 +import info.globalcode.sql.dk.SQLType;
1.31 +import java.io.IOException;
1.32 +import java.util.ArrayList;
1.33 +import java.util.Arrays;
1.34 +import java.util.List;
1.35 +
1.36 +/**
1.37 + *
1.38 + * @author Ing. František Kučera (frantovo.cz)
1.39 + */
1.40 +public class BatchDecoder {
1.41 +
1.42 + public Batch decode(InputStream in) throws BatchException {
1.43 + return new BatchFromStream(new DataInputStream(in));
1.44 +
1.45 + }
1.46 +
1.47 + private class BatchFromStream implements Batch {
1.48 +
1.49 + private DataInputStream in;
1.50 + private boolean hasNext;
1.51 +
1.52 + public BatchFromStream(DataInputStream in) throws BatchException {
1.53 + this.in = in;
1.54 + hasNext = verifyHeader();
1.55 + }
1.56 +
1.57 + @Override
1.58 + public boolean hasNext() throws BatchException {
1.59 + return hasNext;
1.60 + }
1.61 +
1.62 + @Override
1.63 + public SQLCommand next() throws BatchException {
1.64 + try {
1.65 + String sql = readNextString();
1.66 +
1.67 + int paramCount = in.readInt();
1.68 + List<Parameter> parameters = new ArrayList<>(paramCount);
1.69 +
1.70 + for (int i = 0; i < paramCount; i++) {
1.71 + SQLType type = SQLType.valueOf(in.readInt());
1.72 + String value = readNextString();
1.73 + parameters.add(new Parameter(value, type));
1.74 + }
1.75 +
1.76 + hasNext = verifyHeader();
1.77 +
1.78 + SQLCommand sqlCommand = new SQLCommandNumbered(sql, parameters);
1.79 + return sqlCommand;
1.80 + } catch (IOException e) {
1.81 + throw new BatchException("Unable to read batch", e);
1.82 + }
1.83 + }
1.84 +
1.85 + private String readNextString() throws IOException {
1.86 + byte[] buffer = new byte[in.readInt()];
1.87 + in.read(buffer);
1.88 + return new String(buffer, CHARSET);
1.89 + }
1.90 +
1.91 + /**
1.92 + * @return true if correct batch header was found | false if EOF was found
1.93 + * @throws BatchException if unexpected data was found (not batch header nor EOF)
1.94 + */
1.95 + private boolean verifyHeader() throws BatchException {
1.96 + try {
1.97 + byte[] buffer = new byte[BATCH_HEADER.length];
1.98 + int bytesRead = in.read(buffer);
1.99 +
1.100 + if (bytesRead == BATCH_HEADER.length && Arrays.equals(buffer, BATCH_HEADER)) {
1.101 + return true;
1.102 + } else if (bytesRead == -1) {
1.103 + return false;
1.104 + } else {
1.105 + throw new BatchException("This is not SQL-DK batch: " + toHex(buffer));
1.106 + }
1.107 + } catch (IOException e) {
1.108 + throw new BatchException("Unable to read batch header", e);
1.109 + }
1.110 +
1.111 + }
1.112 + }
1.113 +}