Package org.freedesktop.dbus.messages

Class Message

java.lang.Object
org.freedesktop.dbus.messages.Message
Direct Known Subclasses:
DBusSignal, Error, MethodBase
public class Message extends Object
Superclass of all messages which are sent over the Bus. This class deals with all the marshalling to/from the wire format.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    Message.ArgumentType
    Defines constants for each argument type.
    static interface 
    Message.Endian
    Defines constants representing the endianness of the message.
    (package private) static interface 
    Message.ExtractMethod
    Interface defining a method to extract a specific data type.
    static interface 
    Message.Flags
    Defines constants representing the flags which can be set on a message.
    static interface 
    Message.HeaderField
    Defines constants for each valid header field type.
    static interface 
    Message.MessageType
    Defines constants for each message type.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private Object[]
    args
     
    private boolean
    big
     
    private byte[]
    body
     
    private long
    bodylen
     
    private static final int
    BUFFERINCREMENT
    Steps to increment the buffer array.
    private int
    bufferuse
     
    private long
    bytecounter
     
    private final List<FileDescriptor>
    filedescriptors
     
    private byte
    flags
     
    private static final AtomicLong
    GLOBAL_SERIAL
     
    private final Object[]
    headers
     
    protected final org.slf4j.Logger
    logger
     
    static final int
    MAXIMUM_ARRAY_LENGTH
     
    static final int
    MAXIMUM_MESSAGE_LENGTH
     
    static final int
    MAXIMUM_NUM_UNIX_FDS
     
    private static final int
    OFFSET_DATA
    Position of data offset in int array.
    private static final int
    OFFSET_SIG
    Position of signature offset in int array.
    private byte[]
    pabuf
     
    private static byte[][]
    padding
    Keep a static reference to each size of padding array to prevent allocation.
    private int
    paofs
     
    private int
    preallocated
     
    static final byte
    PROTOCOL
    The current protocol major version.
    private byte
    protover
     
    private long
    serial
     
    private byte
    type
     
    private byte[][]
    wiredata
     

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    Message()
    Create a blank message.
    protected
    Message(byte _endian, byte _type, byte _flags)
    Create a message; only to be called by sub-classes.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    align(int _current, byte _type)
    Align a counter to the given type.
    void
    append(String _sig, Object... _data)
    Append a series of values to the message.
    protected void
    appendByte(byte _b)
    Appends a byte to the buffer list.
    protected void
    appendBytes(byte[] _buf)
    Appends a buffer to the buffer list.
    void
    appendint(long _l, int _width)
    Marshalls an integer of a given width and appends it to the message.
    private int
    appendOne(byte[] _sigb, int _sigofs, Object _data)
    Appends a value to the message.
    protected Object[]
    createHeaderArgs(byte _header, String _argType, Object _value)
    Creates a message header.
    static long
    demarshallint(byte[] _buf, int _ofs, byte _endian, int _width)
    Demarshalls an integer of a given width from a buffer.
    long
    demarshallint(byte[] _buf, int _ofs, int _width)
    Demarshalls an integer of a given width from a buffer.
    static long
    demarshallintBig(byte[] _buf, int _ofs, int _width)
    Demarshalls an integer of a given width from a buffer using big-endian format.
    static long
    demarshallintLittle(byte[] _buf, int _ofs, int _width)
    Demarshalls an integer of a given width from a buffer using little-endian format.
    (package private) String
    dumpWireData()
    Dumps the current content of wiredata to String.
    private void
    ensureBuffers(int _num)
    Ensures there are enough free buffers.
    Object[]
    extract(String _signature, byte[] _dataBuf, int _offsets)
    Demarshall values from a buffer.
    Object[]
    extract(String _signature, byte[] _dataBuf, int[] _offsets)
    Demarshall values from a buffer.
    (package private) Object[]
    extract(String _signature, byte[] _dataBuf, int[] _offsets, Message.ExtractMethod _method)
     
    private Object
    extractArray(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained, Message.ExtractMethod _extractMethod)
    Extracts an array from the data received on bus.
    private Object
    extractByte(byte[] _dataBuf, int[] _offsets)
    Extracts a byte from the data received on bus.
    (package private) Object[]
    extractHeader(byte[] _headers)
    Extracts the header information from the given byte array.
    private Object
    extractOne(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained)
    Demarshall one value from a buffer.
    private Object
    extractStruct(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, Message.ExtractMethod _extractMethod)
    Extracts a struct from the data received on bus.
    private Object
    extractVariant(byte[] _dataBuf, int[] _offsets, BiFunction<String,Object,Object> _variantFactory)
    Extracts a Variant from the data received on bus.
    static int
    getAlignment(byte _type)
    Return the alignment for a given type.
    (package private) long
    getBodylen()
     
    protected long
    getByteCounter()
     
    String
    getDestination()
    Returns the destination of the message.
    byte
    getEndianess()
     
    List<FileDescriptor>
    getFiledescriptors()
     
    int
    getFlags()
    Returns the message flags.
    protected Object[]
    getHeader()
     
    Object
    getHeader(byte _type)
    Returns the value of the header field of a given field.
    static String
    getHeaderFieldName(byte _field)
    Returns the name of the given header field.
    protected Map<Byte,Object>
    getHeaders()
    Deprecated, for removal: This API element is subject to removal in a future version.
    use getHeader().
    String
    getInterface()
    Returns the interface of the message.
    String
    getName()
    Returns the member name or error name this message represents.
    Object[]
    getParameters()
    Parses and returns the parameters to this message as an Object array.
    String
    getPath()
    Returns the object path of the message.
    (package private) byte
    getProtover()
     
    long
    getReplySerial()
    If this is a reply to a message, this returns its serial.
    long
    getSerial()
    Returns the message serial ID (unique for this connection)
    String
    getSig()
    Returns the dbus signature of the parameters.
    String
    getSource()
    Returns the Bus ID that sent the message.
    byte
    getType()
    Type of this message.
    protected byte[][]
    getWiredata()
     
    byte[][]
    getWireData()
     
    void
    marshallint(long _l, byte[] _buf, int _ofs, int _width)
    Marshalls an integer of a given width into a buffer.
    static void
    marshallintBig(long _l, byte[] _buf, int _ofs, int _width)
    Marshalls an integer of a given width into a buffer using big-endian format.
    static void
    marshallintLittle(long _l, byte[] _buf, int _ofs, int _width)
    Marshalls an integer of a given width into a buffer using little-endian format.
    private Object
    optimizePrimitives(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, long _size, byte _algn, int _length, Message.ExtractMethod _extractMethod)
    Will create primitive arrays when an array is read.
    void
    pad(byte _type)
    Pad the message to the proper alignment for the given type.
    protected void
    padAndMarshall(List<Object> _hargs, long _serial, String _sig, Object... _args)
    Adds message padding and marshalling.
    (package private) void
    populate(byte[] _msg, byte[] _headers, byte[] _body, List<FileDescriptor> _descriptors)
    Create a message from wire-format data.
    private void
    preallocate(int _num)
    Create a buffer of num bytes.
    private int
    prepareCollection(byte[] _signatureBuf, int[] _offsets, long _size)
     
    private Object
    readHeaderVariants(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained)
    Special lightweight version to read the variant objects in DBus message header.
    void
    setArgs(Object[] _args)
     
    protected void
    setByteCounter(long _bytecounter)
     
    protected void
    setHeader(Object[] _header)
    Set header content.
    protected void
    setSerial(long _serial)
     
    void
    setSource(String _source)
    Warning, do not use this method unless you really know what you are doing.
    protected void
    setWiredata(byte[][] _wiredata)
     
    String
    toString()
    Formats the message in a human-readable format.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  • Field Details

    • MAXIMUM_ARRAY_LENGTH

      public static final int MAXIMUM_ARRAY_LENGTH
      See Also:

    • MAXIMUM_MESSAGE_LENGTH

      public static final int MAXIMUM_MESSAGE_LENGTH
      See Also:

    • MAXIMUM_NUM_UNIX_FDS

      public static final int MAXIMUM_NUM_UNIX_FDS
      See Also:

    • PROTOCOL

      public static final byte PROTOCOL
      The current protocol major version.
      See Also:

    • OFFSET_DATA

      private static final int OFFSET_DATA
      Position of data offset in int array.
      See Also:

    • OFFSET_SIG

      private static final int OFFSET_SIG
      Position of signature offset in int array.
      See Also:

    • padding

      private static byte[][] padding
      Keep a static reference to each size of padding array to prevent allocation.

    • BUFFERINCREMENT

      private static final int BUFFERINCREMENT
      Steps to increment the buffer array.
      See Also:

    • GLOBAL_SERIAL

      private static final AtomicLong GLOBAL_SERIAL

    • logger

      protected final org.slf4j.Logger logger

    • filedescriptors

      private final List<FileDescriptor> filedescriptors

    • headers

      private final Object[] headers

    • wiredata

      private byte[][] wiredata

    • bytecounter

      private long bytecounter

    • serial

      private long serial

    • type

      private byte type

    • flags

      private byte flags

    • protover

      private byte protover

    • big

      private boolean big

    • args

      private Object[] args

    • body

      private byte[] body

    • bodylen

      private long bodylen

    • preallocated

      private int preallocated

    • paofs

      private int paofs

    • pabuf

      private byte[] pabuf

    • bufferuse

      private int bufferuse

  • Constructor Details

    • Message

      protected Message(byte _endian, byte _type, byte _flags) throws DBusException
      Create a message; only to be called by sub-classes.
      Parameters:
      _endian - The endianness to create the message.
      _type - The message type.
      _flags - Any message flags.
      Throws:
      DBusException - on error

    • Message

      protected Message()
      Create a blank message. Only to be used when calling populate.

  • Method Details

    • populate

      void populate(byte[] _msg, byte[] _headers, byte[] _body, List<FileDescriptor> _descriptors) throws DBusException
      Create a message from wire-format data.
      Parameters:
      _msg - D-Bus serialized data of type yyyuu
      _headers - D-Bus serialized data of type a(yv)
      _body - D-Bus serialized data of the signature defined in headers.
      Throws:
      DBusException

    • getHeaders

      @Deprecated(forRemoval=true, since="4.2.2 - 2023-01-19") protected Map<Byte,Object> getHeaders()
      Deprecated, for removal: This API element is subject to removal in a future version.
      use getHeader(). This method did return a map containing message header. It allows changing the map, but changes did not result in changing the actual message header. Therefore using a map was removed and an object array is used instead. Changes to that array (content) will be result in a changed header in the message.
      Returns:
      map of header

    • getHeader

      protected Object[] getHeader()

    • setHeader

      protected void setHeader(Object[] _header)
      Set header content. null value is ignored.
      Parameters:
      _header - header to set

    • getByteCounter

      protected long getByteCounter()

    • setByteCounter

      protected void setByteCounter(long _bytecounter)

    • setSerial

      protected void setSerial(long _serial)

    • getWiredata

      protected byte[][] getWiredata()

    • setWiredata

      protected void setWiredata(byte[][] _wiredata)

    • getProtover

      byte getProtover()

    • getBodylen

      long getBodylen()

    • preallocate

      private void preallocate(int _num)
      Create a buffer of num bytes. Data is copied to this rather than added to the buffer list.

    • ensureBuffers

      private void ensureBuffers(int _num)
      Ensures there are enough free buffers.
      Parameters:
      _num - number of free buffers to create.

    • appendBytes

      protected void appendBytes(byte[] _buf)
      Appends a buffer to the buffer list.
      Parameters:
      _buf - buffer byte array

    • appendByte

      protected void appendByte(byte _b)
      Appends a byte to the buffer list.
      Parameters:
      _b - byte

    • demarshallint

      public long demarshallint(byte[] _buf, int _ofs, int _width)
      Demarshalls an integer of a given width from a buffer. Endianness is determined from the format of the message.
      Parameters:
      _buf - The buffer to demarshall from.
      _ofs - The offset to demarshall from.
      _width - The byte-width of the int.
      Returns:
      long

    • demarshallint

      public static long demarshallint(byte[] _buf, int _ofs, byte _endian, int _width)
      Demarshalls an integer of a given width from a buffer.
      Parameters:
      _buf - The buffer to demarshall from.
      _ofs - The offset to demarshall from.
      _endian - The endianness to use in demarshalling.
      _width - The byte-width of the int.
      Returns:
      long

    • demarshallintBig

      public static long demarshallintBig(byte[] _buf, int _ofs, int _width)
      Demarshalls an integer of a given width from a buffer using big-endian format.
      Parameters:
      _buf - The buffer to demarshall from.
      _ofs - The offset to demarshall from.
      _width - The byte-width of the int.
      Returns:
      long

    • demarshallintLittle

      public static long demarshallintLittle(byte[] _buf, int _ofs, int _width)
      Demarshalls an integer of a given width from a buffer using little-endian format.
      Parameters:
      _buf - The buffer to demarshall from.
      _ofs - The offset to demarshall from.
      _width - The byte-width of the int.
      Returns:
      long

    • appendint

      public void appendint(long _l, int _width)
      Marshalls an integer of a given width and appends it to the message. Endianness is determined from the message.
      Parameters:
      _l - The integer to marshall.
      _width - The byte-width of the int.

    • marshallint

      public void marshallint(long _l, byte[] _buf, int _ofs, int _width)
      Marshalls an integer of a given width into a buffer. Endianness is determined from the message.
      Parameters:
      _l - The integer to marshall.
      _buf - The buffer to marshall to.
      _ofs - The offset to marshall to.
      _width - The byte-width of the int.

    • marshallintBig

      public static void marshallintBig(long _l, byte[] _buf, int _ofs, int _width)
      Marshalls an integer of a given width into a buffer using big-endian format.
      Parameters:
      _l - The integer to marshall.
      _buf - The buffer to marshall to.
      _ofs - The offset to marshall to.
      _width - The byte-width of the int.

    • marshallintLittle

      public static void marshallintLittle(long _l, byte[] _buf, int _ofs, int _width)
      Marshalls an integer of a given width into a buffer using little-endian format.
      Parameters:
      _l - The integer to marshall.
      _buf - The buffer to demarshall to.
      _ofs - The offset to demarshall to.
      _width - The byte-width of the int.

    • getWireData

      public byte[][] getWireData()

    • getFiledescriptors

      public List<FileDescriptor> getFiledescriptors()

    • toString

      public String toString()
      Formats the message in a human-readable format.
      Overrides:
      toString in class Object

    • getHeader

      public Object getHeader(byte _type)
      Returns the value of the header field of a given field.
      Parameters:
      _type - The field to return.
      Returns:
      The value of the field or null if unset.

    • appendOne

      private int appendOne(byte[] _sigb, int _sigofs, Object _data) throws DBusException
      Appends a value to the message. The type of the value is read from a D-Bus signature and used to marshall the value.
      Parameters:
      _sigb - A buffer of the D-Bus signature.
      _sigofs - The offset into the signature corresponding to this value.
      _data - The value to marshall.
      Returns:
      The offset into the signature of the end of this value's type.
      Throws:
      DBusException

    • pad

      public void pad(byte _type)
      Pad the message to the proper alignment for the given type.
      Parameters:
      _type - type

    • getAlignment

      public static int getAlignment(byte _type)
      Return the alignment for a given type.
      Parameters:
      _type - type
      Returns:
      int

    • append

      public void append(String _sig, Object... _data) throws DBusException
      Append a series of values to the message.
      Parameters:
      _sig - The signature(s) of the value(s).
      _data - The value(s).
      Throws:
      DBusException - on error

    • align

      public int align(int _current, byte _type)
      Align a counter to the given type.
      Parameters:
      _current - The current counter.
      _type - The type to align to.
      Returns:
      The new, aligned, counter.

    • extractHeader

      Object[] extractHeader(byte[] _headers) throws DBusException
      Extracts the header information from the given byte array.
      Parameters:
      _headers - D-Bus serialized data of type a(yv)
      Returns:
      Object array containing header data
      Throws:
      DBusException - when parsing fails

    • readHeaderVariants

      private Object readHeaderVariants(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained) throws DBusException
      Special lightweight version to read the variant objects in DBus message header. This method will not create Variant objects it directly extracts the Variant data content.
      Parameters:
      _signatureBuf - DBus signature string as byte array
      _dataBuf - buffer with header data
      _offsets - current offsets
      _contained - boolean to indicate if nested lists should be resolved (false usually)
      Returns:
      Object
      Throws:
      DBusException - when parsing fails

    • extractOne

      private Object extractOne(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained) throws DBusException
      Demarshall one value from a buffer.
      Parameters:
      _signatureBuf - A buffer of the D-Bus signature.
      _dataBuf - The buffer to demarshall from.
      _offsets - An array of two ints, which holds the position of the current signature offset and the current offset of the data buffer.
      _contained - converts nested arrays to Lists
      Returns:
      The demarshalled value.
      Throws:
      DBusException

    • extractByte

      private Object extractByte(byte[] _dataBuf, int[] _offsets)
      Extracts a byte from the data received on bus.
      Parameters:
      _dataBuf - buffer holding the byte
      _offsets - offset position in buffer (will be updated)
      Returns:
      Object

    • extractStruct

      private Object extractStruct(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, Message.ExtractMethod _extractMethod) throws DBusException
      Extracts a struct from the data received on bus.
      Parameters:
      _signatureBuf - signature (as byte array) defining the struct content
      _dataBuf - buffer containing the struct
      _offsets - offset position in buffer (will be updated)
      _extractMethod - method to be called for every entry contained of the struct
      Returns:
      Object
      Throws:
      DBusException - when parsing fails

    • extractArray

      private Object extractArray(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, boolean _contained, Message.ExtractMethod _extractMethod) throws MarshallingException, DBusException
      Extracts an array from the data received on bus.
      Parameters:
      _signatureBuf - signature string (as byte array) of the content of the array
      _dataBuf - buffer containing the array to read
      _offsets - current offsets in the buffer (will be updated)
      _contained - resolve nested lists
      _extractMethod - method to be called for every entry contained in the array
      Returns:
      Object
      Throws:
      MarshallingException - when Array is too large
      DBusException - when parsing fails

    • extractVariant

      private Object extractVariant(byte[] _dataBuf, int[] _offsets, BiFunction<String,Object,Object> _variantFactory) throws DBusException
      Extracts a Variant from the data received on bus.
      Parameters:
      _dataBuf - buffer containing the variant
      _offsets - current offsets in the buffer (will be updated)
      _variantFactory - method to create new Variant objects (or other object types)
      Returns:
      Object / Variant
      Throws:
      DBusException - when parsing fails

    • optimizePrimitives

      private Object optimizePrimitives(byte[] _signatureBuf, byte[] _dataBuf, int[] _offsets, long _size, byte _algn, int _length, Message.ExtractMethod _extractMethod) throws DBusException
      Will create primitive arrays when an array is read.
      In case the array is not compatible with primitives (e.g. object types are used or array contains Struct/Maps etc) an array of the appropriate type will be created.
      Parameters:
      _signatureBuf - signature string (as byte array) containing the type of array
      _dataBuf - buffer containing the array
      _offsets - current offset in buffer (will be updated)
      _size - size of a byte
      _algn - data offset padding width when reading primitives (except byte)
      _length - length of the array
      _extractMethod - method to be called for every entry contained in the array if not primitive array
      Returns:
      Object array
      Throws:
      DBusException - when parsing fails

    • prepareCollection

      private int prepareCollection(byte[] _signatureBuf, int[] _offsets, long _size) throws DBusException
      Throws:
      DBusException

    • extract

      public Object[] extract(String _signature, byte[] _dataBuf, int _offsets) throws DBusException
      Demarshall values from a buffer.
      Parameters:
      _signature - The D-Bus signature(s) of the value(s).
      _dataBuf - The buffer to demarshall from.
      _offsets - The offset into the data buffer to start.
      Returns:
      The demarshalled value(s).
      Throws:
      DBusException - on error

    • extract

      public Object[] extract(String _signature, byte[] _dataBuf, int[] _offsets) throws DBusException
      Demarshall values from a buffer.
      Parameters:
      _signature - The D-Bus signature(s) of the value(s).
      _dataBuf - The buffer to demarshall from.
      _offsets - An array of two ints, which holds the position of the current signature offset and the current offset of the data buffer. These values will be updated to the start of the next value after demarshalling.
      Returns:
      The demarshalled value(s).
      Throws:
      DBusException - on error

    • extract

      Object[] extract(String _signature, byte[] _dataBuf, int[] _offsets, Message.ExtractMethod _method) throws DBusException
      Throws:
      DBusException

    • getSource

      public String getSource()
      Returns the Bus ID that sent the message.
      Returns:
      string

    • getDestination

      public String getDestination()
      Returns the destination of the message.
      Returns:
      string

    • getInterface

      public String getInterface()
      Returns the interface of the message.
      Returns:
      string

    • getPath

      public String getPath()
      Returns the object path of the message.
      Returns:
      string

    • getName

      public String getName()
      Returns the member name or error name this message represents.
      Returns:
      string

    • getSig

      public String getSig()
      Returns the dbus signature of the parameters.
      Returns:
      string

    • getFlags

      public int getFlags()
      Returns the message flags.
      Returns:
      int

    • getSerial

      public long getSerial()
      Returns the message serial ID (unique for this connection)
      Returns:
      the message serial.

    • getReplySerial

      public long getReplySerial()
      If this is a reply to a message, this returns its serial.
      Returns:
      The reply serial, or 0 if it is not a reply.

    • getParameters

      public Object[] getParameters() throws DBusException
      Parses and returns the parameters to this message as an Object array.
      Returns:
      object array
      Throws:
      DBusException - on failure

    • setArgs

      public void setArgs(Object[] _args)

    • setSource

      public void setSource(String _source) throws DBusException
      Warning, do not use this method unless you really know what you are doing.
      Parameters:
      _source - string
      Throws:
      DBusException - on error

    • dumpWireData

      String dumpWireData()
      Dumps the current content of wiredata to String.
      Returns:
      String, maybe empty
      Since:
      v4.2.2 - 2023-01-20

    • getType

      public byte getType()
      Type of this message.
      Returns:
      byte

    • getEndianess

      public byte getEndianess()

    • createHeaderArgs

      protected Object[] createHeaderArgs(byte _header, String _argType, Object _value)
      Creates a message header. Will automatically add the values to the current instances header map.
      Parameters:
      _header - header type (one of Message.HeaderField)
      _argType - argument type (one of Message.ArgumentType)
      _value - value
      Returns:
      Object array

    • padAndMarshall

      protected void padAndMarshall(List<Object> _hargs, long _serial, String _sig, Object... _args) throws DBusException
      Adds message padding and marshalling.
      Parameters:
      _hargs -
      _serial -
      _sig -
      _args -
      Throws:
      DBusException

    • getHeaderFieldName

      public static String getHeaderFieldName(byte _field)
      Returns the name of the given header field.
      Parameters:
      _field - field
      Returns:
      string