Package org.jgroups

Class EmptyMessage

    • Constructor Detail

      • EmptyMessage

        public EmptyMessage()

      • EmptyMessage

        public EmptyMessage​(Address dest)

    • Method Detail

      • getType

        public short getType()
        Description copied from interface: Message
        Returns the type of the message, e.g. BYTES_MSG, OBJ_MSG etc

      • create

        public java.util.function.Supplier<Message> create()
        Description copied from interface: Constructable
        Creates an instance of the class implementing this interface

      • hasPayload

        public boolean hasPayload()
        Description copied from interface: Message
        Returns true if the message has a payload, e.g. a byte[] array in a BytesMessage or an object in an ObjectMessage. This is more generic than Message.hasArray(), as it is not just applicable to a byte array.
        Returns:
        True if the message has a payload

      • hasArray

        public boolean hasArray()
        Description copied from interface: Message
        Returns true if this message has a byte[] array as payload (even if it's null!), false otherwise

      • getArray

        public byte[] getArray()
        Description copied from interface: Message
        Returns a reference to the payload (byte array). Note that this array should not be modified as we do not copy the array on copy() or clone(): the array of the copied message is simply a reference to the old array.
        Even if offset and length are used: we return the entire array, not a subset.
        Throws an exception if the message does not have a byte[] array payload (Message.hasArray() is false).
        Note that this is a convenience method, as most messages are of type BytesMessage. It is recommended to downcast a Message to the correct subtype and use the methods available there to get/set the payload.

      • getOffset

        public int getOffset()
        Description copied from interface: Message
        Returns the offset of the byte[] array at which user data starts. Throws an exception if the message does not have a byte[] array payload (if Message.hasArray() is false).
        Note that this is a convenience method, as most messages are of type BytesMessage.

      • getLength

        public int getLength()
        Description copied from interface: Message
        Returns the length of the byte[] array payload. If the message does not have a byte[] array payload (Message.hasArray() is false), then the serialized size may be returned, or an implementation may choose to throw an exception

      • setArray

        public EmptyMessage setArray​(byte[] b,
                             int off,
                             int len)
        Description copied from interface: Message
        Sets the byte array in a message.
        Throws an exception if the message does not have a byte[] array payload (Message.hasArray() is false).
        Note that this is a convenience method, as most messages are of type BytesMessage. It is recommended to downcast a Message to the correct subtype and use the methods available there to get/set the payload.

      • setArray

        public EmptyMessage setArray​(ByteArray buf)
        Description copied from interface: Message
        Sets the byte array in a message.
        Throws an exception if the message does not have a byte[] array payload (Message.hasArray() is false).
        Note that this is a convenience method, as most messages are of type BytesMessage. It is recommended to downcast a Message to the correct subtype and use the methods available there to get/set the payload.

      • getObject

        public <T> T getObject()
        Description copied from interface: Message
        Gets an object from the payload. If the payload is a byte[] array (e.g. as in BytesMessage), an attempt to de-serialize the array into an object is made, and the object returned.
        If the payload is an object (e.g. as is the case in ObjectMessage), the object will be returned directly.

      • setObject

        public EmptyMessage setObject​(java.lang.Object obj)
        Description copied from interface: Message
        Sets an object in a message. In a ObjectMessage, the object is set directly. In a BytesMessage, the object is serialized into a byte[] array and then the array is set as the payload of the message

      • writePayload

        public void writePayload​(java.io.DataOutput out)
                  throws java.io.IOException
        Throws:
        java.io.IOException

      • readPayload

        public void readPayload​(java.io.DataInput in)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException
        Throws:
        java.io.IOException
        java.lang.ClassNotFoundException