commons-net.jar is the bytecode of Apache Commons Net library, which implements the client side of many basic Internet protocols.

Apache Commons Net Source Code files are provided in the binary packge (commons-net-3.8.0-bin.zip). You can download it at Apache Commons Net Website.

The source code of commons-net-3.8.0.jar is provided below:

⏎ org/apache/commons/net/tftp/TFTPErrorPacket.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.net.tftp;

import java.net.DatagramPacket;
import java.net.InetAddress;

/**
 * A final class derived from TFTPPacket definiing the TFTP Error
 * packet type.
 * <p>
 * Details regarding the TFTP protocol and the format of TFTP packets can
 * be found in RFC 783.  But the point of these classes is to keep you
 * from having to worry about the internals.  Additionally, only very
 * few people should have to care about any of the TFTPPacket classes
 * or derived classes.  Almost all users should only be concerned with the
 * {@link org.apache.commons.net.tftp.TFTPClient} class
 * {@link org.apache.commons.net.tftp.TFTPClient#receiveFile receiveFile()}
 * and
 * {@link org.apache.commons.net.tftp.TFTPClient#sendFile sendFile()}
 * methods.
 *
 *
 * @see TFTPPacket
 * @see TFTPPacketException
 * @see TFTP
 */

public final class TFTPErrorPacket extends TFTPPacket
{
    /** The undefined error code according to RFC 783, value 0. */
    public static final int UNDEFINED = 0;

    /** The file not found error code according to RFC 783, value 1. */
    public static final int FILE_NOT_FOUND = 1;

    /** The access violation error code according to RFC 783, value 2. */
    public static final int ACCESS_VIOLATION = 2;

    /** The disk full error code according to RFC 783, value 3. */
    public static final int OUT_OF_SPACE = 3;

    /**
     * The illegal TFTP operation error code according to RFC 783, value 4.
     */
    public static final int ILLEGAL_OPERATION = 4;

    /** The unknown transfer id error code according to RFC 783, value 5. */
    public static final int UNKNOWN_TID = 5;

    /** The file already exists error code according to RFC 783, value 6. */
    public static final int FILE_EXISTS = 6;

    /** The no such user error code according to RFC 783, value 7. */
    public static final int NO_SUCH_USER = 7;

    /** The error code of this packet. */
    private final int error;

    /** The error message of this packet. */
    private final String message;

    /**
     * Creates an error packet to be sent to a host at a given port
     * with an error code and error message.
     *
     * @param destination  The host to which the packet is going to be sent.
     * @param port  The port to which the packet is going to be sent.
     * @param error The error code of the packet.
     * @param message The error message of the packet.
     */
    public TFTPErrorPacket(final InetAddress destination, final int port,
                           final int error, final String message)
    {
        super(TFTPPacket.ERROR, destination, port);

        this.error = error;
        this.message = message;
    }

    /**
     * Creates an error packet based from a received
     * datagram.  Assumes the datagram is at least length 4, else an
     * ArrayIndexOutOfBoundsException may be thrown.
     *
     * @param datagram  The datagram containing the received error.
     * @throws TFTPPacketException  If the datagram isn't a valid TFTP
     *         error packet.
     */
    TFTPErrorPacket(final DatagramPacket datagram) throws TFTPPacketException
    {
        super(TFTPPacket.ERROR, datagram.getAddress(), datagram.getPort());
        int index;
        final int length;
        final byte[] data;
        final StringBuilder buffer;

        data = datagram.getData();
        length = datagram.getLength();

        if (getType() != data[1]) {
            throw new TFTPPacketException("TFTP operator code does not match type.");
        }

        error = (data[2] & 0xff) << 8 | data[3] & 0xff;

        if (length < 5) {
            throw new TFTPPacketException("Bad error packet. No message.");
        }

        index = 4;
        buffer = new StringBuilder();

        while (index < length && data[index] != 0)
        {
            buffer.append((char)data[index]);
            ++index;
        }

        message = buffer.toString();
    }

    /**
     * This is a method only available within the package for
     * implementing efficient datagram transport by elminating buffering.
     * It takes a datagram as an argument, and a byte buffer in which
     * to store the raw datagram data.  Inside the method, the data
     * is set as the datagram's data and the datagram returned.
     *
     * @param datagram  The datagram to create.
     * @param data The buffer to store the packet and to use in the datagram.
     * @return The datagram argument.
     */
    @Override
    DatagramPacket newDatagram(final DatagramPacket datagram, final byte[] data)
    {
        final int length;

        length = message.length();

        data[0] = 0;
        data[1] = (byte)type;
        data[2] = (byte)((error & 0xffff) >> 8);
        data[3] = (byte)(error & 0xff);

        System.arraycopy(message.getBytes(), 0, data, 4, length);

        data[length + 4] = 0;

        datagram.setAddress(address);
        datagram.setPort(port);
        datagram.setData(data);
        datagram.setLength(length + 4);

        return datagram;
    }


    /**
     * Creates a UDP datagram containing all the TFTP
     * error packet data in the proper format.
     * This is a method exposed to the programmer in case he
     * wants to implement his own TFTP client instead of using
     * the {@link org.apache.commons.net.tftp.TFTPClient}
     * class.
     * Under normal circumstances, you should not have a need to call this
     * method.
     *
     * @return A UDP datagram containing the TFTP error packet.
     */
    @Override
    public DatagramPacket newDatagram()
    {
        final byte[] data;
        final int length;

        length = message.length();

        data = new byte[length + 5];
        data[0] = 0;
        data[1] = (byte)type;
        data[2] = (byte)((error & 0xffff) >> 8);
        data[3] = (byte)(error & 0xff);

        System.arraycopy(message.getBytes(), 0, data, 4, length);

        data[length + 4] = 0;

        return new DatagramPacket(data, data.length, address, port);
    }


    /**
     * Returns the error code of the packet.
     *
     * @return The error code of the packet.
     */
    public int getError()
    {
        return error;
    }


    /**
     * Returns the error message of the packet.
     *
     * @return The error message of the packet.
     */
    public String getMessage()
    {
        return message;
    }

    /**
     * For debugging
     * @since 3.6
     */
    @Override
    public String toString() {
        return super.toString() + " ERR " + error + " " + message;
    }
}

⏎ org/apache/commons/net/tftp/TFTPErrorPacket.java

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File name: commons-net-3.8.0-sources.jar
File size: 437325 bytes
Release date: 2020-01-22
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