How to serialize ByteBuffer

I wish to send a java.nio.ByteBuffer accross a network using RMI, however ByteBuffer isn'开发者_开发知识库t serializable. I've tried the following custom class to no avail:

public class NetByteBuffer implements java.io.Serializable {

ByteBuffer buffer;

public NetByteBuffer(ByteBuffer buffer) {
    this.buffer = buffer;
}

public ByteBuffer getByteBuffer() {
    return this.buffer;
}

}

The client still gets a non-serialzable exception. Any ideas?

Thanks

You can't. You'd better obtain the byte[] and send it instead and reconstruct the ByteBuffer on the other side. You are of course losing the advantages of it being a buffer.

Like others said ByteBuffer is a wrap of a buffer of bytes so if you need to serialize your class is better to change to byte[] and use ByteBuffer in the classes which are reading/writing data into this bean.

But if you need to serialize a ByteBuffer property (for example usign Cassandra blobs) you can always implement a custom serialization (check this url http://www.oracle.com/technetwork/articles/java/javaserial-1536170.html).

The main points are:

1. mark ByteBuffer as transient (so it's not serialized by default)
2. implement your own read/write for serialization where ByteBuffer --> byte[] when serializing and byte[] --> ByteBuffer on deserializing.

Try this class and let me know if this works for you:

public class NetByteBuffer implements java.io.Serializable {
    private static final long serialVersionUID = -2831273345165209113L;

    //serializable property
    String anotherProperty;

    // mark as transient so this is not serialized by default
    transient ByteBuffer data;

    public NetByteBuffer(String anotherProperty, ByteBuffer data) {
        this.data = data;
        this.anotherProperty = anotherProperty;
    }

    public ByteBuffer getData() {
        return this.data;
    }

    private void writeObject(ObjectOutputStream out) throws IOException {
        // write default properties
        out.defaultWriteObject();
        // write buffer capacity and data
        out.writeInt(data.capacity());
        out.write(data.array());

    }

    private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
        //read default properties
        in.defaultReadObject();

        //read buffer data and wrap with ByteBuffer
        int bufferSize = in.readInt();
        byte[] buffer = new byte[bufferSize];
        in.read(buffer, 0, bufferSize);
        this.data = ByteBuffer.wrap(buffer, 0, bufferSize);
    }

    public String getAnotherProperty() {
        return anotherProperty;
    }

}

You probably need to say more about why you're serializing a byte buffer. If you're simply trying to send a bunch of bytes across the network, @Bozho's answer has got you covered.

If you actually want to send across a ByteBuffer including its contents and state, you probably need to rethink your design, or at the very least explain it here so others can provide more direction.

Long way but your goal can be accomplish:

u can create a remote object with instance variable type of "ByteBuffer" and defined the getter and setter remote methods to access that variable.