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.net.mysql; import io.netty.buffer.ByteBuf; import java.nio.ByteBuffer; import org.opencloudb.mysql.BufferUtil; import org.opencloudb.mysql.MySQLMessage; import org.opencloudb.net.FrontendConnection; /** * From Server To Client, part of Result Set Packets. One for each column in the * result set. Thus, if the value of field_columns in the Result Set Header * Packet is 3, then the Field Packet occurs 3 times. * * <pre> * Bytes Name * ----- ---- * n (Length Coded String) catalog * n (Length Coded String) db * n (Length Coded String) table * n (Length Coded String) org_table * n (Length Coded String) name * n (Length Coded String) org_name * 1 (filler) * 2 charsetNumber * 4 length * 1 type * 2 flags * 1 decimals * 2 (filler), always 0x00 * n (Length Coded Binary) default * * @see http://forge.mysql.com/wiki/MySQL_Internals_ClientServer_Protocol#Field_Packet * </pre> * * @author mycat */ public class FieldPacket extends MySQLPacket { private static final byte[] DEFAULT_CATALOG = "def".getBytes(); private static final byte[] FILLER = new byte[2]; public byte[] catalog = DEFAULT_CATALOG; public byte[] db; public byte[] table; public byte[] orgTable; public byte[] name; public byte[] orgName; public int charsetIndex; public long length; public int type; public int flags; public byte decimals; public byte[] definition; /** * ??FieldPacket */ public void read(byte[] data) { MySQLMessage mm = new MySQLMessage(data); this.packetLength = mm.readUB3(); this.packetId = mm.read(); readBody(mm); } /** * BinaryPacket??FieldPacket */ public void read(BinaryPacket bin) { this.packetLength = bin.packetLength; this.packetId = bin.packetId; readBody(new MySQLMessage(bin.data)); } @Override public ByteBuffer write(ByteBuffer buffer, FrontendConnection c, boolean writeSocketIfFull) { int size = calcPacketSize(); buffer = c.checkWriteBuffer(buffer, c.getPacketHeaderSize() + size, writeSocketIfFull); BufferUtil.writeUB3(buffer, size); buffer.put(packetId); writeBody(buffer); return buffer; } public ByteBuf write(ByteBuf buffer) { int size = calcPacketSize(); BufferUtil.writeUB3(buffer, size); buffer.writeByte(packetId); writeBody(buffer); return buffer; } @Override public int calcPacketSize() { int size = (catalog == null ? 1 : BufferUtil.getLength(catalog)); size += (db == null ? 1 : BufferUtil.getLength(db)); size += (table == null ? 1 : BufferUtil.getLength(table)); size += (orgTable == null ? 1 : BufferUtil.getLength(orgTable)); size += (name == null ? 1 : BufferUtil.getLength(name)); size += (orgName == null ? 1 : BufferUtil.getLength(orgName)); size += 13;// 1+2+4+1+2+1+2 if (definition != null) { size += BufferUtil.getLength(definition); } return size; } @Override protected String getPacketInfo() { return "MySQL Field Packet"; } private void readBody(MySQLMessage mm) { this.catalog = mm.readBytesWithLength(); this.db = mm.readBytesWithLength(); this.table = mm.readBytesWithLength(); this.orgTable = mm.readBytesWithLength(); this.name = mm.readBytesWithLength(); this.orgName = mm.readBytesWithLength(); mm.move(1); this.charsetIndex = mm.readUB2(); this.length = mm.readUB4(); this.type = mm.read() & 0xff; this.flags = mm.readUB2(); this.decimals = mm.read(); mm.move(FILLER.length); if (mm.hasRemaining()) { this.definition = mm.readBytesWithLength(); } } private void writeBody(ByteBuffer buffer) { byte nullVal = 0; BufferUtil.writeWithLength(buffer, catalog, nullVal); BufferUtil.writeWithLength(buffer, db, nullVal); BufferUtil.writeWithLength(buffer, table, nullVal); BufferUtil.writeWithLength(buffer, orgTable, nullVal); BufferUtil.writeWithLength(buffer, name, nullVal); BufferUtil.writeWithLength(buffer, orgName, nullVal); buffer.put((byte) 0x0C); BufferUtil.writeUB2(buffer, charsetIndex); BufferUtil.writeUB4(buffer, length); buffer.put((byte) (type & 0xff)); BufferUtil.writeUB2(buffer, flags); buffer.put(decimals); buffer.position(buffer.position() + FILLER.length); if (definition != null) { BufferUtil.writeWithLength(buffer, definition); } } private void writeBody(ByteBuf buffer) { byte nullVal = 0; BufferUtil.writeWithLength(buffer, catalog, nullVal); BufferUtil.writeWithLength(buffer, db, nullVal); BufferUtil.writeWithLength(buffer, table, nullVal); BufferUtil.writeWithLength(buffer, orgTable, nullVal); BufferUtil.writeWithLength(buffer, name, nullVal); BufferUtil.writeWithLength(buffer, orgName, nullVal); buffer.writeByte((byte) 0x0C); BufferUtil.writeUB2(buffer, charsetIndex); BufferUtil.writeUB4(buffer, length); buffer.writeByte((byte) (type & 0xff)); BufferUtil.writeUB2(buffer, flags); buffer.writeByte(decimals); buffer.writerIndex(buffer.writerIndex() + FILLER.length); if (definition != null) { BufferUtil.writeWithLength(buffer, definition); } } }