pdu.java

snmp4j 1.8.2版 The org.snmp4j classes are capable of creating, sending, and receiving SNMPv1/v2c/v3

   * @see SnmpConstants
   */
  public void setErrorStatus(int errorStatus) {
    this.errorStatus.setValue(errorStatus);
  }

  /**
   * Gets the error status of the PDU.
   * @return
   *    a SNMP error status.
   * @see SnmpConstants
   */
  public int getErrorStatus() {
    return errorStatus.getValue();
  }

  /**
   * Gets a textual description of the error status.
   * @return
   *    a String containing an element of the
   *    {@link SnmpConstants#SNMP_ERROR_MESSAGES} array for a valid error status.
   *    "Unknown error: <errorStatusNumber>" is returned for any other value.
   */
  public String getErrorStatusText() {
    return toErrorStatusText(errorStatus.getValue());
  }

  /**
   * Returns textual description for the supplied error status value.
   * @param errorStatus
   *    an error status.
   * @return
   *    a String containing an element of the
   *    {@link SnmpConstants#SNMP_ERROR_MESSAGES} array for a valid error status.
   *    "Unknown error: <errorStatusNumber>" is returned for any other value.
   * @since 1.7
   */
  public static final String toErrorStatusText(int errorStatus) {
    try {
      return SnmpConstants.SNMP_ERROR_MESSAGES[errorStatus];
    }
    catch (ArrayIndexOutOfBoundsException iobex) {
      return "Unknown error: "+errorStatus;
    }
  }

  /**
   * Sets the error index.
   * @param errorIndex
   *    an integer value >= 0 where 1 denotes the first variable binding.
   */
  public void setErrorIndex(int errorIndex) {
    this.errorIndex.setValue(errorIndex);
  }

  /**
   * Gets the error index.
   * @return
   *   an integer value >= 0 where 1 denotes the first variable binding.
   */
  public int getErrorIndex() {
    return errorIndex.getValue();
  }

  /**
   * Checks whether this PDU is a confirmed class PDU.
   * @return boolean
   */
  public boolean isConfirmedPdu() {
    return ((type != PDU.REPORT) && (type != PDU.RESPONSE) &&
            (type != PDU.TRAP) && (type != PDU.V1TRAP));
  }

  public int getBERLength() {
    // header for data_pdu
    int length = getBERPayloadLengthPDU();
    length += BER.getBERLengthOfLength(length) + 1;
    // assume maxmimum length here
    return length;
  }

  public int getBERPayloadLength() {
    return getBERPayloadLengthPDU();
  }

  public void decodeBER(BERInputStream inputStream) throws IOException {
    BER.MutableByte pduType = new BER.MutableByte();
    int length = BER.decodeHeader(inputStream, pduType);
    int pduStartPos = (int)inputStream.getPosition();
    switch (pduType.getValue()) {
      case PDU.SET:
      case PDU.GET:
      case PDU.GETNEXT:
      case PDU.GETBULK:
      case PDU.INFORM:
      case PDU.REPORT:
      case PDU.TRAP:
      case PDU.RESPONSE:
        break;
      default:
        throw new IOException("Unsupported PDU type: "+pduType.getValue());
    }
    this.type = pduType.getValue();
    requestID.decodeBER(inputStream);
    errorStatus.decodeBER(inputStream);
    errorIndex.decodeBER(inputStream);

    pduType = new BER.MutableByte();
    int vbLength = BER.decodeHeader(inputStream, pduType);
    if (pduType.getValue() != BER.SEQUENCE) {
      throw new IOException("Encountered invalid tag, SEQUENCE expected: "+
                            pduType.getValue());
    }
    // rest read count
    int startPos = (int)inputStream.getPosition();
    variableBindings = new Vector();
    while (inputStream.getPosition() - startPos < vbLength) {
      VariableBinding vb = new VariableBinding();
      vb.decodeBER(inputStream);
      variableBindings.add(vb);
    }
    if (inputStream.getPosition() - startPos != vbLength) {
      throw new IOException("Length of VB sequence ("+vbLength+
                            ") does not match real length: "+
                            ((int)inputStream.getPosition()-startPos));
    }
    if (BER.isCheckSequenceLength()) {
      BER.checkSequenceLength(length,
                              (int) inputStream.getPosition() - pduStartPos,
                              this);
    }
  }

  protected int getBERPayloadLengthPDU() {
    int length = 0;

    // length for all vbs
    for (int i = 0; i < variableBindings.size(); i++) {
      length += ((VariableBinding)variableBindings.get(i)).getBERLength();
    }

    length += BER.getBERLengthOfLength(length) + 1;

    // req id, error status, error index
    Integer32 i32 = new Integer32(requestID.getValue());
    length += i32.getBERLength();
    i32 = errorStatus;
    length += i32.getBERLength();
    i32 = errorIndex;
    length += i32.getBERLength();
    i32 = null;
    return length;
  }

  public void encodeBER(OutputStream outputStream) throws IOException {
    BER.encodeHeader(outputStream, type, getBERPayloadLengthPDU());

    requestID.encodeBER(outputStream);
    errorStatus.encodeBER(outputStream);
    errorIndex.encodeBER(outputStream);

    int vbLength = 0;
    for (int i=0; i<variableBindings.size(); i++) {
      vbLength += ((VariableBinding)variableBindings.get(i)).getBERLength();
    }
    BER.encodeHeader(outputStream, BER.SEQUENCE, vbLength);
    for (int i=0; i<variableBindings.size(); i++) {
      ((VariableBinding)variableBindings.get(i)).encodeBER(outputStream);
    }
  }

  /**
   * Removes all variable bindings from the PDU and sets the request ID to zero.
   * This can be used to reuse a PDU for another request.
   */
  public void clear() {
    variableBindings.clear();
    setRequestID(new Integer32(0));
  }

  /**
   * Sets the PDU type.
   * @param type
   *    the type of the PDU (e.g. GETNEXT, SET, etc.)
   */
  public void setType(int type) {
    this.type = type;
  }

  /**
   * Gets the PDU type. The default is {@link PDU#GETNEXT}.
   * @return
   *    the PDU's type.
   */
  public int getType() {
    return type;
  }

  public Object clone() {
    return new PDU(this);
  }

  /**
   * Gets the request ID associated with this PDU.
   * @return
   *    an <code>Integer32</code> instance.
   */
  public Integer32 getRequestID() {
    return requestID;
  }

  /**
   * Sets the request ID for this PDU. When the request ID is not set or set to
   * zero, the message processing model will generate a unique request ID for
   * the <code>PDU</code> when sent.
   * @param requestID
   *    a unique request ID.
   */
  public void setRequestID(Integer32 requestID) {
    this.requestID = requestID;
  }

  /**
   * Gets a string representation of the supplied PDU type.
   * @param type
   *    a PDU type.
   * @return
   *    a string representation of <code>type</code>, for example "GET".
   */
  public static String getTypeString(int type) {
    switch (type) {
      case PDU.GET:
        return "GET";
      case PDU.SET:
        return "SET";
      case PDU.GETNEXT:
        return "GETNEXT";
      case PDU.GETBULK:
        return "GETBULK";
      case PDU.INFORM:
        return "INFORM";
      case PDU.RESPONSE:
        return "RESPONSE";
      case PDU.REPORT:
        return "REPORT";
      case PDU.TRAP:
        return "TRAP";
      case PDU.V1TRAP:
        return "V1TRAP";
    }
    return "unknown";
  }

  /**
   * Gets the PDU type identifier for a string representation of the type.
   * @param type
   *    the string representation of a PDU type: <code>GET, GETNEXT, GETBULK,
   *    SET, INFORM, RESPONSE, REPORT, TRAP, V1TRAP)</code>.
   * @return
   *    the corresponding PDU type constant, or <code>Integer.MIN_VALUE</code>
   *    of the supplied type is unknown.
   */
  public static int getTypeFromString(String type) {
    if (type.equals("GET")) {
      return PDU.GET;
    }
    else if (type.equals("SET")) {
      return PDU.SET;
    }
    else if (type.equals("GETNEXT")) {
      return PDU.GETNEXT;
    }
    else if (type.equals("GETBULK")) {
      return PDU.GETBULK;
    }
    else if (type.equals("INFORM")) {
      return PDU.INFORM;
    }
    else if (type.equals("RESPONSE")) {
      return PDU.RESPONSE;
    }
    else if (type.equals("TRAP")) {
      return PDU.TRAP;
    }
    else if (type.equals("V1TRAP")) {
      return PDU.V1TRAP;
    }
    else if (type.equals("REPORT")) {
      return PDU.REPORT;
    }
    return Integer.MIN_VALUE;
  }

  /**
   * Returns a string representation of the object.
   *
   * @return a string representation of the object.
   */
  public String toString() {
    StringBuffer buf = new StringBuffer();
    buf.append(getTypeString(type));
    buf.append("[requestID=");
    buf.append(requestID);
    buf.append(", errorStatus=");
    buf.append(getErrorStatusText()+"("+errorStatus+")");
    buf.append(", errorIndex=");
    buf.append(errorIndex);
    buf.append(", VBS[");
    for (int i=0; i<variableBindings.size(); i++) {
      buf.append(variableBindings.get(i));
      if (i+1 < variableBindings.size()) {
        buf.append("; ");
      }
    }
    buf.append("]]");
    return buf.toString();
  }

  /**
   * Gets the maximum repetitions of repeatable variable bindings in GETBULK
   * requests.
   * @return
   *    an integer value >= 0.
   */
  public int getMaxRepetitions() {
    return errorIndex.getValue();
  }

  /**
   * Sets the maximum repetitions of repeatable variable bindings in GETBULK
   * requests.
   * @param maxRepetitions
   *    an integer value >= 0.
   */
  public void setMaxRepetitions(int maxRepetitions) {
    this.errorIndex.setValue(maxRepetitions);
  }

  /**
   * Gets the number of non repeater variable bindings in a GETBULK PDU.
   * @return
   *    an integer value >= 0 and <= {@link #size()}
   */
  public int getNonRepeaters() {
    return errorStatus.getValue();
  }

  /**
   * Sets the number of non repeater variable bindings in a GETBULK PDU.
   * @param nonRepeaters
   *    an integer value >= 0 and <= {@link #size()}
   */
  public void setNonRepeaters(int nonRepeaters) {
    this.errorStatus.setValue(nonRepeaters);
  }

  /**
   * Returns an array with the variable bindings of this PDU.
   * @return
   *    an array of <code>VariableBinding</code> instances of this PDU in the
   *    same order as in the PDU.
   */
  public VariableBinding[] toArray() {
    VariableBinding[] vbs = new VariableBinding[this.variableBindings.size()];
    this.variableBindings.toArray(vbs);
    return vbs;
  }
}