Question

I would like to write a byte arrays in a file with Camel. But, in order to get back my arrays, I want to write them line by line, or with another separator.
How to do that with Camel ?

from(somewhere)
    .process(new Processor() {

      @Override
      public void process(final Exchange exchange) throws Exception {
        final MyObject body = exchange.getIn().getBody(MyObject.class);

        byte[] serializedObject = MySerializer.serialize(body);
        exchange.getOut().setBody(serializedObject);

        exchange.getOut().setHeader(Exchange.FILE_NAME, "filename");
      }
    }).to("file://filepath?fileExist=Append&autoCreate=true");

Or is anyone have another way to get them back ?

PS : I need to have only one file, otherwise it would have been too easy …

EDIT :
I successfully write my file line by line with the out.writeObject method (Thanks to Petter). And I can read them with :

InputStream file = new FileInputStream(FILENAME);
InputStream buffer = new BufferedInputStream(file);
input = new ObjectInputStream(buffer);

Object obj = null;
while ((obj = input.readObject()) != null) {
        // Do something
}

But I not able to split and read them with camel. Do you have any idea to read them with Camel ?

Answer 1

It depends on what your serialized object looks like, since you seem to have your own serializer. Is it standard java binary

ByteArrayOutputStream bos = new ByteArrayOuputStream();
ObjectOutput out = new ObjectOutputStream(bos);
out.writeObject(obj);
return bos.toByteArray();

I probably won’t be such a great idea to use text based separators like \n.

Can’t you serialize into some text format instead? Camel has several easy to use data formats: (http://camel.apache.org/data-format.html). Xstream, for instance, is a line of code or so, to create XML from your objects, then it’s not big deal to split the file into several XML parts and read them back with XStream.

In your example, if you really want a separator, why don’t you just append it to the byte[]? Copy the array to a new, bigger byte[] and insert some unique sequence in the end.