mysqlio.java

基于java的oa系统

        if ((this.reusablePacket != null)
                && (this.reusablePacket.getBufLength() > 1048576)) {
            this.reusablePacket = new Buffer(this.connection.getNetBufferLength());
        }
    }

    /**
     * Re-use a packet to read from the MySQL server
     *
     * @param reuse DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     *
     * @throws SQLException DOCUMENT ME!
     * @throws SQLException DOCUMENT ME!
     */
    private final Buffer reuseAndReadPacket(Buffer reuse)
        throws SQLException {
        try {
            reuse.setWasMultiPacket(false);

            int lengthRead = readFully(mysqlInput, this.packetHeaderBuf, 0, 4);

            if (lengthRead < 4) {
                forceClose();
                throw new IOException("Unexpected end of input stream");
            }

            int packetLength = ((int) (this.packetHeaderBuf[0] & 0xff))
                + (((int) (this.packetHeaderBuf[1] & 0xff)) << 8)
                + (((int) (this.packetHeaderBuf[2] & 0xff)) << 16);

            byte multiPacketSeq = this.packetHeaderBuf[3];

            //byte multiPacketSeq = (byte) this.mysqlInput.read();
            // Set the Buffer to it's original state
            reuse.setPosition(0);
            reuse.setSendLength(0);

            // Do we need to re-alloc the byte buffer?
            //
            // Note: We actually check the length of the buffer,
            // rather than getBufLength(), because getBufLength() is not
            // necesarily the actual length of the byte array
            // used as the buffer
            if (reuse.getByteBuffer().length <= packetLength) {
                reuse.setByteBuffer(new byte[packetLength + 1]);
            }

            // Set the new length
            reuse.setBufLength(packetLength);

            // Read the data from the server
            readFully(this.mysqlInput, reuse.getByteBuffer(), 0, packetLength);

            boolean isMultiPacket = false;

            if (packetLength == maxThreeBytes) {
                reuse.setPosition((int) maxThreeBytes);

                int packetEndPoint = packetLength;

                // it's multi-packet
                isMultiPacket = true;

                lengthRead = readFully(mysqlInput, this.packetHeaderBuf, 0, 4);

                if (lengthRead < 4) {
                    forceClose();
                    throw new IOException("Unexpected end of input stream");
                }

                packetLength = ((int) (this.packetHeaderBuf[0] & 0xff))
                    + (((int) (this.packetHeaderBuf[1] & 0xff)) << 8)
                    + (((int) (this.packetHeaderBuf[2] & 0xff)) << 16);

                Buffer multiPacket = new Buffer(packetLength);
                boolean firstMultiPkt = true;

                while (true) {
                    if (!firstMultiPkt) {
                        lengthRead = readFully(mysqlInput,
                                this.packetHeaderBuf, 0, 4);

                        if (lengthRead < 4) {
                            forceClose();
                            throw new IOException(
                                "Unexpected end of input stream");
                        }

                        packetLength = ((int) (this.packetHeaderBuf[0] & 0xff))
                            + (((int) (this.packetHeaderBuf[1] & 0xff)) << 8)
                            + (((int) (this.packetHeaderBuf[2] & 0xff)) << 16);
                    } else {
                        firstMultiPkt = false;
                    }

                    if (!this.useNewLargePackets && (packetLength == 1)) {
                        clearInputStream();

                        break;
                    } else if (packetLength < this.maxThreeBytes) {
                        byte newPacketSeq = this.packetHeaderBuf[3];

                        if (newPacketSeq != (multiPacketSeq + 1)) {
                            throw new IOException(
                                "Packets received out of order");
                        }

                        multiPacketSeq = newPacketSeq;

                        // Set the Buffer to it's original state
                        multiPacket.setPosition(0);
                        multiPacket.setSendLength(0);

                        // Set the new length
                        multiPacket.setBufLength(packetLength);

                        // Read the data from the server
                        byte[] byteBuf = multiPacket.getByteBuffer();
                        int lengthToWrite = packetLength;

                        int bytesRead = readFully(this.mysqlInput, byteBuf, 0,
                                packetLength);

                        if (bytesRead != lengthToWrite) {
                            throw new SQLException(
                                "Short read from server, expected "
                                + lengthToWrite + " bytes, received only "
                                + bytesRead + ".",
                                SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE);
                        }

                        reuse.writeBytesNoNull(byteBuf, 0, lengthToWrite);

                        packetEndPoint += lengthToWrite;

                        break; // end of multipacket sequence
                    }

                    byte newPacketSeq = this.packetHeaderBuf[3];

                    if (newPacketSeq != (multiPacketSeq + 1)) {
                        throw new IOException("Packets received out of order");
                    }

                    multiPacketSeq = newPacketSeq;

                    // Set the Buffer to it's original state
                    multiPacket.setPosition(0);
                    multiPacket.setSendLength(0);

                    // Set the new length
                    multiPacket.setBufLength(packetLength);

                    // Read the data from the server
                    byte[] byteBuf = multiPacket.getByteBuffer();
                    int lengthToWrite = packetLength;

                    int bytesRead = readFully(this.mysqlInput, byteBuf, 0,
                            packetLength);

                    if (bytesRead != lengthToWrite) {
                        throw new SQLException(
                            "Short read from server, expected " + lengthToWrite
                            + " bytes, received only " + bytesRead + ".",
                            SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE);
                    }

                    reuse.writeBytesNoNull(byteBuf, 0, lengthToWrite);

                    packetEndPoint += lengthToWrite;
                }

                //reuse.writeByte((byte) 0);
                reuse.setPosition(0);
                reuse.setWasMultiPacket(true);
            }

            if (!isMultiPacket) {
                reuse.getByteBuffer()[packetLength] = 0; // Null-termination
            }

            return reuse;
        } catch (IOException ioEx) {
            StringBuffer message = new StringBuffer(SQLError.get(
                        SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE));
            message.append(": ");
            message.append(ioEx.getClass().getName());
            message.append(", underlying cause: ");
            message.append(ioEx.getMessage());

            if (!this.connection.useParanoidErrorMessages()) {
                message.append(Util.stackTraceToString(ioEx));
            }

            throw new java.sql.SQLException(message.toString(),
                SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE, 0);
        }
    }

    /**
     * Send a packet to the MySQL server
     *
     * @param packet DOCUMENT ME!
     *
     * @throws SQLException DOCUMENT ME!
     */
    private final void send(Buffer packet) throws SQLException {
        int l = packet.getPosition();
        send(packet, l);

        // 
        // Don't hold on to large packets
        //
        if (packet == this.sharedSendPacket) {
            reclaimLargeSharedSendPacket();
        }
    }

    private final void send(Buffer packet, int packetLen)
        throws SQLException {
        try {
            if (packetLen > this.maxAllowedPacket) {
                throw new PacketTooBigException(packetLen, this.maxAllowedPacket);
            }

            if ((serverMajorVersion >= 4) && (packetLen >= maxThreeBytes)) {
                sendSplitPackets(packet);
            } else {
                this.packetSequence++;

                Buffer packetToSend = packet;

                packetToSend.setPosition(0);

                if (this.useCompression) {
                    packetToSend = compressPacket(packet, 0, packetLen,
                            HEADER_LENGTH);
                    packetLen = packetToSend.getPosition();
                } else {
                    packetToSend.writeLongInt(packetLen - HEADER_LENGTH);
                    packetToSend.writeByte(this.packetSequence);
                }

                this.mysqlOutput.write(packetToSend.getByteBuffer(), 0,
                    packetLen);
                this.mysqlOutput.flush();
            }

            // 
            // Don't hold on to large packets
            //
            if (packet == this.sharedSendPacket) {
                reclaimLargeSharedSendPacket();
            }
        } catch (IOException ioEx) {
            StringBuffer message = new StringBuffer(SQLError.get(
                        SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE));
            message.append(": ");
            message.append(ioEx.getClass().getName());
            message.append(", underlying cause: ");
            message.append(ioEx.getMessage());

            if (!this.connection.useParanoidErrorMessages()) {
                message.append(Util.stackTraceToString(ioEx));
            }

            throw new java.sql.SQLException(message.toString(),
                SQLError.SQL_STATE_COMMUNICATION_LINK_FAILURE, 0);
        }
    }

    /**
     * Reads and sends a file to the server for LOAD DATA LOCAL INFILE
     *
     * @param fileName the file name to send.
     *
     * @return DOCUMENT ME!
     *
     * @throws SQLException DOCUMENT ME!
     */
    private final ResultSet sendFileToServer(String fileName)
        throws SQLException {
        Buffer filePacket = (loadFileBufRef == null) ? null
                                                     : (Buffer) (loadFileBufRef
            .get());

        int packetLength = Math.min(this.connection.getMaxAllowedPacket()
                - (HEADER_LENGTH * 3),
                alignPacketSize(this.connection.getMaxAllowedPacket() - 16, 4096)
                - (HEADER_LENGTH * 3));

        //
        // This packet may be _way_ too large to actually allocate,
        // unforunately, LOAD DATA LOCAL INFILE requires this setup...
        //
        try {
            if (filePacket == null) {
                filePacket = new Buffer((int) (packetLength + HEADER_LENGTH));
                loadFileBufRef = new SoftReference(filePacket);
            }
        } catch (OutOfMemoryError oom) {
            // Attempt to do this, but it might not work...
            // The server is expecting at least one packet, so we 
            // send an empty 'EOF' packet...
            this.reusablePacket.clear();
            send(this.reusablePacket);

            throw new SQLException("Unable to allocate packet of size '"
                + (packetLength + HEADER_LENGTH)
                + "' for LOAD DATA LOCAL INFILE. Either increase heap space available to your JVM, or adjust the MySQL server variable 'max_allowed_packet'",
                SQLError.SQL_STATE_MEMORY_ALLOCATION_FAILURE);
        }

        filePacket.clear();
        send(filePacket, 0);

        byte[] fileBuf = new byte[packetLength];

        BufferedInputStream fileIn = null;

        try {
            fileIn = new BufferedInputStream(new FileInputStream(fileName));

            int bytesRead = 0;

            while ((bytesRead = fileIn.read(fileBuf)) != -1) {
                filePacket.clear();
                filePacket.writeBytesNoNull(fileBuf, 0, bytesRead);
                send(filePacket);
            }
        } catch (IOException ioEx) {
            StringBuffer messageBuf = new StringBuffer("Unable to open file ");

            if (!this.connection.useParanoidErrorMessages()) {
                messageBuf.append("'");

                if (fileName != null) {
                    messageBuf.append(fileName);
                }

                messageBuf.append("'");
            }

            messageBuf.append("for 'LOAD DATA LOCAL INFILE' command.");

            if (!this.connection.useParanoidErrorMessages()) {
                messageBuf.append("Due to underlying IOException: ");
                messageBuf.append(Util.stackTraceToString(ioEx));
            }

            throw new SQLException(messageBuf.toString(),
                SQLError.SQL_STATE_ILLEGAL_ARGUMENT);
        } finally {
            if (fileIn != null) {
                try {
                    fileIn.close();
                } catch (Exception ex) {
                    throw new SQLException("Unable to close local file during LOAD DATA LOCAL INFILE command",
                        SQLError.SQL_STATE_GENERAL_ERROR);
                }

                fileIn = null;
            } else {
                // file open failed, but server needs one packet
                filePacket.clear();
                send(filePacket);
            }
        }

        // send empty packet to mark EOF
        filePacket.clear();
        send(filePacket);

        Buffer resultPacket = checkErrorPacket();

        return buildResultSetWithUpdat