Java tutorial
/* * Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software;Designed and Developed mainly by many Chinese * opensource volunteers. you can redistribute it and/or modify it under the * terms of the GNU General Public License version 2 only, as published by the * Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Any questions about this component can be directed to it's project Web address * https://code.google.com/p/opencloudb/. * */ package org.opencloudb.server.response; import com.google.common.base.Splitter; import org.apache.log4j.Logger; import org.opencloudb.backend.BackendConnection; import org.opencloudb.config.Fields; import org.opencloudb.mysql.PacketUtil; import org.opencloudb.net.mysql.EOFPacket; import org.opencloudb.net.mysql.FieldPacket; import org.opencloudb.net.mysql.ResultSetHeaderPacket; import org.opencloudb.net.mysql.RowDataPacket; import org.opencloudb.server.NonBlockingSession; import org.opencloudb.server.ServerConnection; import org.opencloudb.util.LongUtil; import org.opencloudb.util.StringUtil; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * @author mycat */ public final class SelectVariables { private static final Logger LOGGER = Logger.getLogger(SelectVariables.class); public static void execute(ServerConnection c, String sql) { String subSql = sql.substring(sql.indexOf("SELECT") + 6); List<String> splitVar = Splitter.on(",").omitEmptyStrings().trimResults().splitToList(subSql); splitVar = convert(splitVar); int FIELD_COUNT = splitVar.size(); ResultSetHeaderPacket header = PacketUtil.getHeader(FIELD_COUNT); FieldPacket[] fields = new FieldPacket[FIELD_COUNT]; int i = 0; byte packetId = 0; header.packetId = ++packetId; for (int i1 = 0, splitVarSize = splitVar.size(); i1 < splitVarSize; i1++) { String s = splitVar.get(i1); fields[i] = PacketUtil.getField(s, Fields.FIELD_TYPE_VAR_STRING); fields[i++].packetId = ++packetId; } ByteBuffer buffer = c.allocate(); // write header buffer = header.write(buffer, c, true); // write fields for (FieldPacket field : fields) { buffer = field.write(buffer, c, true); } EOFPacket eof = new EOFPacket(); eof.packetId = ++packetId; // write eof buffer = eof.write(buffer, c, true); // write rows //byte packetId = eof.packetId; RowDataPacket row = new RowDataPacket(FIELD_COUNT); for (int i1 = 0, splitVarSize = splitVar.size(); i1 < splitVarSize; i1++) { String s = splitVar.get(i1); String value = variables.get(s) == null ? "" : variables.get(s); row.add(value.getBytes()); } row.packetId = ++packetId; buffer = row.write(buffer, c, true); // write lastEof EOFPacket lastEof = new EOFPacket(); lastEof.packetId = ++packetId; buffer = lastEof.write(buffer, c, true); // write buffer c.write(buffer); } private static List<String> convert(List<String> in) { List<String> out = new ArrayList<>(); for (String s : in) { int asIndex = s.toUpperCase().indexOf(" AS "); if (asIndex != -1) { out.add(s.substring(asIndex + 4)); } } if (out.isEmpty()) { return in; } else { return out; } } private static final Map<String, String> variables = new HashMap<String, String>(); static { variables.put("@@character_set_client", "utf8"); variables.put("@@character_set_connection", "utf8"); variables.put("@@character_set_results", "utf8"); variables.put("@@character_set_server", "utf8"); variables.put("@@init_connect", ""); variables.put("@@interactive_timeout", "172800"); variables.put("@@license", "GPL"); variables.put("@@lower_case_table_names", "1"); variables.put("@@max_allowed_packet", "16777216"); variables.put("@@net_buffer_length", "16384"); variables.put("@@net_write_timeout", "60"); variables.put("@@query_cache_size", "0"); variables.put("@@query_cache_type", "OFF"); variables.put("@@sql_mode", "STRICT_TRANS_TABLES"); variables.put("@@system_time_zone", "CST"); variables.put("@@time_zone", "SYSTEM"); variables.put("@@tx_isolation", "REPEATABLE-READ"); variables.put("@@wait_timeout", "172800"); variables.put("@@session.auto_increment_increment", "1"); variables.put("character_set_client", "utf8"); variables.put("character_set_connection", "utf8"); variables.put("character_set_results", "utf8"); variables.put("character_set_server", "utf8"); variables.put("init_connect", ""); variables.put("interactive_timeout", "172800"); variables.put("license", "GPL"); variables.put("lower_case_table_names", "1"); variables.put("max_allowed_packet", "16777216"); variables.put("net_buffer_length", "16384"); variables.put("net_write_timeout", "60"); variables.put("query_cache_size", "0"); variables.put("query_cache_type", "OFF"); variables.put("sql_mode", "STRICT_TRANS_TABLES"); variables.put("system_time_zone", "CST"); variables.put("time_zone", "SYSTEM"); variables.put("tx_isolation", "REPEATABLE-READ"); variables.put("wait_timeout", "172800"); variables.put("auto_increment_increment", "1"); } }