serverpreparedstatement.java

mysql的jdbc驱动

	 * Used by Connection when auto-reconnecting to retrieve 'lost' prepared
	 * statements.
	 * 
	 * @throws SQLException
	 *             if an error occurs.
	 */
	protected void rePrepare() throws SQLException {
		this.invalidationException = null;

		try {
			serverPrepare(this.originalSql);
		} catch (SQLException sqlEx) {
			// don't wrap SQLExceptions
			this.invalidationException = sqlEx;
		} catch (Exception ex) {
			this.invalidationException = new SQLException(ex.toString(),
					SQLError.SQL_STATE_GENERAL_ERROR);
		}

		if (this.invalidationException != null) {
			this.invalid = true;

			this.parameterBindings = null;

			this.parameterFields = null;
			this.resultFields = null;

			if (this.results != null) {
				try {
					this.results.close();
				} catch (Exception ex) {
					;
				}
			}

			if (this.connection != null) {
				if (this.maxRowsChanged) {
					this.connection.unsetMaxRows(this);
				}

				if (!this.connection.getDontTrackOpenResources()) {
					this.connection.unregisterStatement(this);
				}
			}
		}
	}

	/**
	 * Tells the server to execute this prepared statement with the current
	 * parameter bindings.
	 * 
	 * <pre>
	 * 
	 * 
	 *    -   Server gets the command 'COM_EXECUTE' to execute the
	 *        previously         prepared query. If there is any param markers;
	 *  then client will send the data in the following format:
	 * 
	 *  [COM_EXECUTE:1]
	 *  [STMT_ID:4]
	 *  [NULL_BITS:(param_count+7)/8)]
	 *  [TYPES_SUPPLIED_BY_CLIENT(0/1):1]
	 *  [[length]data]
	 *  [[length]data] .. [[length]data].
	 * 
	 *  (Note: Except for string/binary types; all other types will not be
	 *  supplied with length field)
	 * 
	 *  
	 * </pre>
	 * 
	 * @param maxRowsToRetrieve
	 *            DOCUMENT ME!
	 * @param createStreamingResultSet
	 *            DOCUMENT ME!
	 * 
	 * @return DOCUMENT ME!
	 * 
	 * @throws SQLException
	 */
	private com.mysql.jdbc.ResultSet serverExecute(int maxRowsToRetrieve,
			boolean createStreamingResultSet) throws SQLException {
		synchronized (this.connection.getMutex()) {
			if (this.detectedLongParameterSwitch) {
				// Check when values were bound
				boolean firstFound = false;
				long boundTimeToCheck = 0;
				
				for (int i = 0; i < this.parameterCount - 1; i++) {
					if (this.parameterBindings[i].isLongData) {
						if (firstFound && boundTimeToCheck != 
							this.parameterBindings[i].boundBeforeExecutionNum) { 					
							throw new SQLException(Messages
									.getString("ServerPreparedStatement.11") //$NON-NLS-1$
									+ Messages.getString("ServerPreparedStatement.12"), //$NON-NLS-1$
									SQLError.SQL_STATE_DRIVER_NOT_CAPABLE);
						} else {
							firstFound = true;
							boundTimeToCheck = this.parameterBindings[i].boundBeforeExecutionNum;
						}
					}
				}
				
				// Okay, we've got all "newly"-bound streams, so reset 
				// server-side state to clear out previous bindings
				
				serverResetStatement();
			}

			// Check bindings
			for (int i = 0; i < this.parameterCount; i++) {
				if (!this.parameterBindings[i].isSet) {
					throw new SQLException(Messages
							.getString("ServerPreparedStatement.13") + (i + 1) //$NON-NLS-1$
							+ Messages.getString("ServerPreparedStatement.14"),
							SQLError.SQL_STATE_ILLEGAL_ARGUMENT); //$NON-NLS-1$
				}
			}

			//
			// Send all long data
			//
			for (int i = 0; i < this.parameterCount; i++) {
				if (this.parameterBindings[i].isLongData) {
					serverLongData(i, this.parameterBindings[i]);
				}
			}

			if (this.connection.getAutoGenerateTestcaseScript()) {
				dumpExecuteForTestcase();
			}

			//
			// store the parameter values
			//
			MysqlIO mysql = this.connection.getIO();

			Buffer packet = mysql.getSharedSendPacket();

			packet.clear();
			packet.writeByte((byte) MysqlDefs.COM_EXECUTE);
			packet.writeLong(this.serverStatementId);

			if (this.connection.versionMeetsMinimum(4, 1, 2)) {
				packet.writeByte((byte) 0); // placeholder for flags
				packet.writeLong(1); // placeholder for parameter iterations
			}

			/* Reserve place for null-marker bytes */
			int nullCount = (this.parameterCount + 7) / 8;

			// if (mysql.versionMeetsMinimum(4, 1, 2)) {
			// nullCount = (this.parameterCount + 9) / 8;
			// }
			int nullBitsPosition = packet.getPosition();

			for (int i = 0; i < nullCount; i++) {
				packet.writeByte((byte) 0);
			}

			byte[] nullBitsBuffer = new byte[nullCount];

			/* In case if buffers (type) altered, indicate to server */
			packet.writeByte(this.sendTypesToServer ? (byte) 1 : (byte) 0);

			if (this.sendTypesToServer) {
				/*
				 * Store types of parameters in first in first package that is
				 * sent to the server.
				 */
				for (int i = 0; i < this.parameterCount; i++) {
					packet.writeInt(this.parameterBindings[i].bufferType);
				}
			}

			//
			// store the parameter values
			//
			for (int i = 0; i < this.parameterCount; i++) {
				if (!this.parameterBindings[i].isLongData) {
					if (!this.parameterBindings[i].isNull) {
						storeBinding(packet, this.parameterBindings[i], mysql);
					} else {
						nullBitsBuffer[i / 8] |= (1 << (i & 7));
					}
				}
			}

			//
			// Go back and write the NULL flags
			// to the beginning of the packet
			//
			int endPosition = packet.getPosition();
			packet.setPosition(nullBitsPosition);
			packet.writeBytesNoNull(nullBitsBuffer);
			packet.setPosition(endPosition);

			long begin = 0;

			if (this.connection.getProfileSql()
					|| this.connection.getLogSlowQueries()
					|| this.connection.getGatherPerformanceMetrics()) {
				begin = System.currentTimeMillis();
			}

			Buffer resultPacket = mysql.sendCommand(MysqlDefs.COM_EXECUTE,
					null, packet, false, null);

			

			this.connection.incrementNumberOfPreparedExecutes();

			if (this.connection.getProfileSql()) {
				this.eventSink = ProfileEventSink.getInstance(this.connection);

				this.eventSink.consumeEvent(new ProfilerEvent(
						ProfilerEvent.TYPE_EXECUTE, "", this.currentCatalog, //$NON-NLS-1$
						this.connection.getId(), this.statementId, -1, System
								.currentTimeMillis(), (int) (System
								.currentTimeMillis() - begin), null,
						new Throwable(), null));
			}

			com.mysql.jdbc.ResultSet rs = mysql.readAllResults(this,
					maxRowsToRetrieve, this.resultSetType,
					this.resultSetConcurrency, createStreamingResultSet,
					this.currentCatalog, resultPacket, true, this.fieldCount,
					true);

			
			if (!createStreamingResultSet && 
					this.serverNeedsResetBeforeEachExecution) {
				serverResetStatement(); // clear any long data...
			}

			this.sendTypesToServer = false;
			this.results = rs;

			if (this.connection.getLogSlowQueries()
					|| this.connection.getGatherPerformanceMetrics()) {
				long elapsedTime = System.currentTimeMillis() - begin;

				if (this.connection.getLogSlowQueries()
						&& (elapsedTime > this.connection
								.getSlowQueryThresholdMillis())) {
					StringBuffer mesgBuf = new StringBuffer(
							48 + this.originalSql.length());
					mesgBuf.append(Messages
							.getString("ServerPreparedStatement.15")); //$NON-NLS-1$
					mesgBuf.append(this.connection
							.getSlowQueryThresholdMillis());
					mesgBuf.append(Messages
							.getString("ServerPreparedStatement.16")); //$NON-NLS-1$
					mesgBuf.append(this.originalSql);

					this.connection.getLog().logWarn(mesgBuf.toString());

					if (this.connection.getExplainSlowQueries()) {
						String queryAsString = asSql(true);

						mysql.explainSlowQuery(queryAsString.getBytes(),
								queryAsString);
					}
				}

				if (this.connection.getGatherPerformanceMetrics()) {
					this.connection.registerQueryExecutionTime(elapsedTime);
				}
			}
			
			return rs;
		}
	}

	/**
	 * Sends stream-type data parameters to the server.
	 * 
	 * <pre>
	 * 
	 *  Long data handling:
	 * 
	 *  - Server gets the long data in pieces with command type 'COM_LONG_DATA'.
	 *  - The packet recieved will have the format as:
	 *    [COM_LONG_DATA:     1][STMT_ID:4][parameter_number:2][type:2][data]
	 *  - Checks if the type is specified by client, and if yes reads the type,
	 *    and  stores the data in that format.
	 *  - It's up to the client to check for read data ended. The server doesn't
	 *    care;  and also server doesn't notify to the client that it got the
	 *    data  or not; if there is any error; then during execute; the error
	 *    will  be returned
	 *  
	 * </pre>
	 * 
	 * @param parameterIndex
	 *            DOCUMENT ME!
	 * @param longData
	 *            DOCUMENT ME!
	 * 
	 * @throws SQLException
	 *             if an error occurs.
	 */
	private void serverLongData(int parameterIndex, BindValue longData)
			throws SQLException {
		synchronized (this.connection.getMutex()) {
			MysqlIO mysql = this.connection.getIO();

			Buffer packet = mysql.getSharedSendPacket();

			Object value = longData.value;

			if (value instanceof byte[]) {
				packet.clear();
				packet.writeByte((byte) MysqlDefs.COM_LONG_DATA);
				packet.writeLong(this.serverStatementId);
				packet.writeInt((parameterIndex));

				packet.writeBytesNoNull((byte[]) longData.value);

				mysql.sendCommand(MysqlDefs.COM_LONG_DATA, null, packet, true,
						null);
			} else if (value instanceof InputStream) {
				storeStream(mysql, parameterIndex, packet, (InputStream) value);
			} else if (value instanceof java.sql.Blob) {
				storeStream(mysql, parameterIndex, packet,
						((java.sql.Blob) value).getBinaryStream());
			} else if (value instanceof Reader) {
				storeReader(mysql, parameterIndex, packet, (Reader) value);
			} else {
				throw new SQLException(Messages
						.getString("ServerPreparedStatement.18") //$NON-NLS-1$
						+ value.getClass().getName() + "'", //$NON-NLS-1$
						SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
			}
		}
	}

	private void serverPrepare(String sql) throws SQLException {
		synchronized (this.connection.getMutex()) {
			MysqlIO mysql = this.connection.getIO();

			if (this.connection.getAutoGenerateTestcaseScript()) {
				dumpPrepareForTestcase();
			}

			try {
				long begin = 0;

				if (StringUtils.startsWithIgnoreCaseAndWs(sql, "LOAD DATA")) { //$NON-NLS-1$
					this.isLoadDataQuery = true;
				} else {
					this.isLoadDataQuery = false;
				}

				if (this.connection.getProfileSql()) {
					begin = System.currentTimeMillis();
				}

				String characterEncoding = null;
				String connectionEncoding = this.connection.getEncoding();

				if (!this.isLoadDataQuery && this.connection.getUseUnicode()
						&& (connectionEncoding != null)) {
					characterEncoding = connectionEncoding;
				}

				Buffer prepareResultPacket = mysql.sendCommand(
						MysqlDefs.COM_PREPARE, sql, null, false,
						characterEncoding);

				if (this.connection.versionMeetsMinimum(4, 1, 1)) {
					// 4.1.1 and newer use the first byte
					// as an 'ok' or 'error' flag, so move
					// the buffer pointer past it to
					// start reading the statement id.
					prepareResultPacket.setPosition(1);
				} else {
					// 4.1.0 doesn't use the first byte as an
					// 'ok' or 'error' flag
					prepareResultPacket.setPosition(0);
				}

				this.serverStatementId = prepareResultPacket.readLong();
				this.fieldCount = prepareResultPacket.readInt();
				this.parameterCount = prepareResultPacket.readInt();
				this.parameterBindings = new BindValue[this.parameterCount];

				for (int i = 0; i < this.parameterCount; i++) {
					this.parameterBindings[i] = new BindValue();
				}

				this.connection.incrementNumberOfPrepares();

				if (this.connection.getProfileSql()) {
					this.eventSink = ProfileEventSink
							.getInstance(this.connection);

					this.eventSink.consumeEvent(new ProfilerEvent(
							ProfilerEvent.TYPE_PREPARE,
							"", this.currentCatalog, //$NON-NLS-1$
							this.connection.getId(), this.statementId, -1,
							System.currentTimeMillis(), (int) (System
									.currentTimeMillis() - begin), null,
							new Throwable(), sql));
				}

				if (this.parameterCount > 0) {
					if (this.connection.versionMeetsMinimum(4, 1, 2)
							&& !mysql.isVersion(5, 0, 0)) {
						this.parameterFields = new Field[this.parameterCount];

						Buffer metaDataPacket = mysql.readPacket();

						int i = 0;

						while (!metaDataPacket.isLastDataPacket()
								&& (i < this.parameterCount)) {
							this.parameterFields[i++] = mysql.unpackField(
									metaDataPacket, false);
							metaDataPacket = mysql.readPacket();
						}
					}
				}

				if (this.fieldCount > 0) {
					this.resultFields = new Field[this.fieldCount];

					Buffer fieldPacket = mysql.readPacket();

					int i = 0;

					// Read in the result set column information
					while (!fieldPacket.isLastDataPacket()
							&& (i < this.fieldCount)) {
						this.resultFields[i++] = mysql.unpackField(fieldPacket,
								false);
						fieldPacket = mysql.readPacket();
					}
				}
			} catch (SQLException sqlEx) {
				if (this.connection.getDumpQueriesOnException()) {
					StringBuffer messageBuf = new StringBuffer(this.originalSql
							.length() + 32);
					messageBuf
							.append("\n\nQuery being prepared when exception was thrown:\n\n");
					messageBuf.append(this.originalSql);

					sqlEx = Connection.appendMessageToException(sqlEx,
							messageBuf.toString());
				}

				throw sqlEx;
			} finally {
				// Leave the I/O channel in a known state...there might be
				// packets out there
				// that we're not interested in
				this.connection.getIO().clearInputStream();
			}