org.nightcode.milter.net.MilterPacket Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jmilter Show documentation
Java implementation of the Sendmail Milter protocol.
There is a newer version: 0.8
/*
 * Licensed 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.nightcode.milter.net;

import org.nightcode.common.base.Hexs;

import java.util.Arrays;
import java.util.Objects;

/**
 * Milter packet.
 */
public final class MilterPacket {

  /**
   * Helper class for creating Milter packet.
   */
  public static final class Builder {
    private int command;
    private byte[] payload = ZERO_ARRAY;

    private Builder() {
      // do nothing
    }

    /**
     * Creates new Milter packet.
     *
     * @return a new Milter packet
     */
    public MilterPacket build() {
      return new MilterPacket(this);
    }

    /**
     * Sets Milter protocol command.
     *
     * @param val milter protocol command
     * @return current Builder instance
     */
    public Builder command(int val) {
      command = val;
      return this;
    }

    /**
     * Sets Milter protocol payload.
     *
     * @param val Milter protocol payload
     * @return current Builder instance
     */
    public Builder payload(byte[] val) {
      Objects.requireNonNull(val, "payload");
      byte[] buffer = new byte[val.length];
      System.arraycopy(val, 0, buffer, 0, val.length);
      payload = buffer;
      return this;
    }

    public Builder payload(byte[] val, int offset, int length) {
      Objects.requireNonNull(val, "payload");
      if (val.length < offset + length) {
        throw new IllegalArgumentException(String.format("buffer length %s less then offset %s plus length %s"
            , val.length, offset, length));
      }
      byte[] buffer = new byte[length];
      System.arraycopy(val, offset, buffer, 0, length);
      payload = buffer;
      return this;
    }
  }

  private static final byte[] ZERO_ARRAY = new byte[0];

  public static final int COMMAND_LENGTH = 1;

  /**
   * Creates new {@link Builder} instance.
   *
   * @return new {@link Builder} instance
   */
  public static Builder builder() {
    return new Builder();
  }

  private final int command;
  private final byte[] payload;

  /**
   * Creates a new Milter packet.
   *
   * @param command Milter protocol command
   */
  public MilterPacket(int command) {
    this(command, ZERO_ARRAY);
  }

  /**
   * Creates a new Milter packet.
   *
   * @param command Milter protocol command
   * @param payload Milter protocol payload
   */
  public MilterPacket(int command, byte[] payload) {
    this(command, payload, 0, payload.length);
  }

  /**
   * Creates a new Milter packet.
   *
   * @param command Milter protocol command
   * @param payload Milter protocol payload
   * @param offset offset in the supplied payload array
   * @param length length of Milter protocol payload
   */
  public MilterPacket(int command, byte[] payload, int offset, int length) {
    this.command = command;
    if (payload.length != 0) {
      this.payload = new byte[length];
      System.arraycopy(payload, offset, this.payload, 0, length);
    } else {
      this.payload = ZERO_ARRAY;
    }
  }

  private MilterPacket(Builder builder) {
    command = builder.command;
    payload = builder.payload;
  }

  /**
   * Returns Milter protocol command.
   *
   * @return Milter protocol command
   */
  public int command() {
    return command;
  }

  /**
   * Returns Milter protocol payload.
   *
   * @return Milter protocol payload
   */
  public byte[] payload() {
    if (payload.length == 0) {
      return ZERO_ARRAY;
    }
    byte[] buffer = new byte[payload.length];
    System.arraycopy(payload, 0, buffer, 0, payload.length);
    return buffer;
  }

  @Override public boolean equals(Object obj) {
    if (obj == this) {
      return true;
    }
    if (!(obj instanceof MilterPacket)) {
      return false;
    }
    MilterPacket other = (MilterPacket) obj;
    return command == other.command && Arrays.equals(payload, other.payload);
  }

  @Override public int hashCode() {
    int result = 17;
    result = 31 * result + command;
    result = 31 * result + Arrays.hashCode(payload);
    return result;
  }

  @Override public String toString() {
    return "MilterPacket{"
        + "command=" + command
        + ", payload=" + ((payload.length > 0) ? Hexs.hex().fromByteArray(payload) : "EMPTY")
        + '}';
  }
}