Java tutorial
package com.tesora.dve.db.mysql.portal.protocol; /* * #%L * Tesora Inc. * Database Virtualization Engine * %% * Copyright (C) 2011 - 2014 Tesora Inc. * %% * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License, version 3, * as published by the Free Software Foundation. * * 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * #L% */ import com.tesora.dve.db.mysql.MyFieldType; import com.tesora.dve.db.mysql.common.DBTypeBasedUtils; import com.tesora.dve.db.mysql.common.MysqlAPIUtils; import com.tesora.dve.db.mysql.libmy.MyNullBitmap; import com.tesora.dve.db.mysql.libmy.MyParameter; import com.tesora.dve.db.mysql.libmy.MyPreparedStatement; import com.tesora.dve.exceptions.PECodingException; import com.tesora.dve.exceptions.PEException; import io.netty.buffer.ByteBuf; import java.nio.ByteOrder; import java.util.List; public class MSPComStmtExecuteRequestMessage extends BaseMSPMessage<MSPComStmtExecuteRequestMessage.ParsedData> { public static final MSPComStmtExecuteRequestMessage PROTOTYPE = new MSPComStmtExecuteRequestMessage(); public static final byte TYPE_IDENTIFIER = (byte) 0x17; static class ParsedData { long statementID; byte flags; long iterationCount; int metadataOffset; MyPreparedStatement<?> metadata; List<Object> values; } protected MSPComStmtExecuteRequestMessage() { super(); } protected MSPComStmtExecuteRequestMessage(ByteBuf backing) { super(backing); } protected MSPComStmtExecuteRequestMessage(ParsedData data) { super(data); } @Override public byte getMysqlMessageType() { return TYPE_IDENTIFIER; } @Override public MSPComStmtExecuteRequestMessage newPrototype(ByteBuf source) { source = source.slice(); return new MSPComStmtExecuteRequestMessage(source); } @Override protected ParsedData unmarshall(ByteBuf source) { ParsedData parseValues = new ParsedData(); source.skipBytes(1);//skip the type identifier. parseValues.statementID = source.readUnsignedInt(); parseValues.flags = source.readByte(); parseValues.iterationCount = source.readUnsignedInt(); parseValues.metadataOffset = source.readerIndex(); //we don't actually unmarshall the metadata and values here, since we don't know how many parameters there are. parseValues.metadata = null; parseValues.values = null; return parseValues; } @Override protected void marshall(ParsedData state, ByteBuf destination) { ByteBuf leBuf = destination.order(ByteOrder.LITTLE_ENDIAN); leBuf.writeByte(TYPE_IDENTIFIER); leBuf.writeInt((int) state.statementID); leBuf.writeByte(state.flags); leBuf.writeInt((int) state.iterationCount); if (state.metadata == null) throw new IllegalStateException("Cannot build execute request, no prepare metadata provided."); int numParams = state.metadata.getNumParams(); if (numParams > 0) { MyNullBitmap nullBitmap = new MyNullBitmap(numParams, MyNullBitmap.BitmapType.EXECUTE_REQUEST); int bitmapIndex = leBuf.writerIndex(); leBuf.writeZero(nullBitmap.length()); if (state.metadata.isNewParameterList()) { leBuf.writeByte(1); for (MyParameter param : state.metadata.getParameters()) { leBuf.writeByte(param.getType().getByteValue()); leBuf.writeZero(1); } } else { leBuf.writeZero(1); } List<Object> params = state.values; for (int i = 0; i < params.size(); ++i) { if (params.get(i) != null) DBTypeBasedUtils.getJavaTypeFunc(params.get(i).getClass()).writeObject(leBuf, params.get(i)); else nullBitmap.setBit(i + 1); } leBuf.setBytes(bitmapIndex, nullBitmap.getBitmapArray()); } } public long getStatementID() { return readState().statementID; } public void readParameterMetadata(MyPreparedStatement<String> pStmt) throws PEException { //TODO: this belongs in unmarshall, but requires knowledge about the expected number of parameters, provided by a previous prepare response. ParsedData cachedParse = readState(); ByteBuf backingData = readBuffer(); int lengthOfMetadata = backingData.readableBytes() - cachedParse.metadataOffset; ByteBuf in = backingData.slice(cachedParse.metadataOffset, lengthOfMetadata).order(ByteOrder.LITTLE_ENDIAN); if (pStmt.getNumParams() > 0) { int nullBitmapLength = (pStmt.getNumParams() + 7) / 8; MyNullBitmap nullBitmap = new MyNullBitmap(MysqlAPIUtils.readBytes(in, nullBitmapLength), pStmt.getNumParams(), MyNullBitmap.BitmapType.EXECUTE_REQUEST); if (in.readByte() == 1) { // this is new params bound flag; only // =1 on first stmt_execute pStmt.clearParameters(); for (int i = 0; i < pStmt.getNumParams(); i++) { pStmt.addParameter(new MyParameter(MyFieldType.fromByte(in.readByte()))); in.skipBytes(1); } } for (int paramNum = 1; paramNum <= pStmt.getNumParams(); paramNum++) { MyParameter parameter = pStmt.getParameter(paramNum); if (nullBitmap.getBit(paramNum)) { parameter.setValue(null); } else { //TODO - may need to figure out how to get the proper flags and length into this call parameter.setValue(DBTypeBasedUtils.getMysqlTypeFunc(parameter.getType()).readObject(in)); } } } } public static MSPComStmtExecuteRequestMessage newMessage(int statementID, MyPreparedStatement<MysqlGroupedPreparedStatementId> metadata, List<Object> values) { if (metadata.getNumParams() > 0 && metadata.getNumParams() != values.size()) throw new PECodingException( "Wrong number of parameters specified for prepared statement execution (expected" + metadata.getNumParams() + ", received " + values.size() + ")"); ParsedData data = new ParsedData(); data.statementID = statementID; data.flags = 0; data.iterationCount = 1; data.metadata = metadata; data.values = values; return new MSPComStmtExecuteRequestMessage(data); } }