MarshalUtils.java

package org.jboss.seam.remoting;

import java.io.IOException;
import java.io.OutputStream;
import java.util.List;

import org.jboss.seam.remoting.model.Model;
import org.jboss.seam.remoting.wrapper.BeanWrapper;
import org.jboss.seam.remoting.wrapper.Wrapper;

/**
 * @author Shane Bryzak
 */
public class MarshalUtils {
    private static final byte[] RESULT_TAG_OPEN = "<result>".getBytes();
    private static final byte[] RESULT_TAG_CLOSE = "</result>".getBytes();

    private static final byte[] MODEL_TAG_OPEN_START = "<model id=\"".getBytes();
    private static final byte[] MODEL_TAG_OPEN_END = "\">".getBytes();
    private static final byte[] MODEL_TAG_CLOSE = "</model>".getBytes();

    private static final byte[] VALUE_TAG_OPEN = "<value>".getBytes();
    private static final byte[] VALUE_TAG_CLOSE = "</value>".getBytes();

    private static final byte[] ALIASED_VALUE_TAG_OPEN_START = "<value alias=\"".getBytes();
    private static final byte[] ALIASED_VALUE_TAG_OPEN_END = "\">".getBytes();
    private static final byte[] ALIASED_VALUE_TAG_CLOSE = "</value>".getBytes();

    private static final byte[] EXCEPTION_TAG_OPEN = "<exception>".getBytes();
    private static final byte[] EXCEPTION_TAG_CLOSE = "</exception>".getBytes();

    private static final byte[] EXCEPTION_CLASS_TAG_OPEN = "<class>".getBytes();
    private static final byte[] EXCEPTION_CLASS_TAG_CLOSE = "</class>".getBytes();
    
    private static final byte[] MESSAGE_TAG_OPEN = "<message>".getBytes();
    private static final byte[] MESSAGE_TAG_CLOSE = "</message>".getBytes();

    public static void marshalCallResult(Call call, OutputStream out)
            throws IOException {
        out.write(RESULT_TAG_OPEN);

        if (call.getException() != null) {
            marshalException(call.getException(), call.getContext(), out);
        } else {
            out.write(VALUE_TAG_OPEN);
            call.getContext().createWrapperFromObject(call.getResult(), "")
                    .marshal(out);
            out.write(VALUE_TAG_CLOSE);

            out.write(RequestHandler.REFS_TAG_OPEN);
            marshalRefs(call.getContext().getOutRefs(), call.getConstraints(), out);
            out.write(RequestHandler.REFS_TAG_CLOSE);
        }

        out.write(RESULT_TAG_CLOSE);
    }

    public static void marshalException(Throwable exception, CallContext ctx, OutputStream out)
            throws IOException {
        out.write(EXCEPTION_TAG_OPEN);
        
        out.write(EXCEPTION_CLASS_TAG_OPEN);
        ctx.createWrapperFromObject(exception.getClass().getName(), "").marshal(out);
        out.write(EXCEPTION_CLASS_TAG_CLOSE);
        
        out.write(MESSAGE_TAG_OPEN);
        ctx.createWrapperFromObject(exception.getMessage(), "").marshal(out);
        out.write(MESSAGE_TAG_CLOSE);
        
        out.write(EXCEPTION_TAG_CLOSE);
    }

    public static void marshalModel(Model model, OutputStream out)
            throws IOException {
        out.write(MODEL_TAG_OPEN_START);
        out.write(model.getId().getBytes());
        out.write(MODEL_TAG_OPEN_END);

        for (String alias : model.getBeanProperties().keySet()) {
            Model.BeanProperty property = model.getBeanProperties().get(alias);

            out.write(ALIASED_VALUE_TAG_OPEN_START);
            out.write(alias.getBytes());
            out.write(ALIASED_VALUE_TAG_OPEN_END);
            model.getCallContext().createWrapperFromObject(property.getValue(), "")
                    .marshal(out);
            out.write(ALIASED_VALUE_TAG_CLOSE);
        }

        out.write(RequestHandler.REFS_TAG_OPEN);
        marshalRefs(model.getCallContext().getOutRefs(), null, out);
        out.write(RequestHandler.REFS_TAG_CLOSE);

        out.write(MODEL_TAG_CLOSE);
    }

    public static void marshalModelExpand(Model model, Wrapper value,
                                          OutputStream out, int newRefIdx)
            throws IOException {
        out.write(MODEL_TAG_OPEN_START);
        out.write(model.getId().getBytes());
        out.write(MODEL_TAG_OPEN_END);

        out.write(RESULT_TAG_OPEN);
        value.marshal(out);
        out.write(RESULT_TAG_CLOSE);

        if (model.getCallContext().getOutRefs().size() > newRefIdx) {
            out.write(RequestHandler.REFS_TAG_OPEN);
            marshalNewRefs(model.getCallContext().getOutRefs(), newRefIdx, null, out);
            out.write(RequestHandler.REFS_TAG_CLOSE);
        }

        out.write(MODEL_TAG_CLOSE);
    }

    public static void marshalNewRefs(List<Wrapper> refs, int startIdx,
                                      List<String> constraints, OutputStream out)
            throws IOException {
        for (int i = startIdx; i < refs.size(); i++) {
            Wrapper wrapper = refs.get(i);

            out.write(RequestHandler.REF_TAG_OPEN_START);
            out.write(Integer.toString(i).getBytes());
            out.write(RequestHandler.REF_TAG_OPEN_END);

            if (wrapper instanceof BeanWrapper && constraints != null) {
                ((BeanWrapper) wrapper).serialize(out, constraints);
            } else {
                wrapper.serialize(out);
            }

            out.write(RequestHandler.REF_TAG_CLOSE);
        }
    }

    public static void marshalRefs(List<Wrapper> refs, List<String> constraints,
                                   OutputStream out)
            throws IOException {
        for (int i = 0; i < refs.size(); i++) {
            Wrapper wrapper = refs.get(i);

            out.write(RequestHandler.REF_TAG_OPEN_START);
            out.write(Integer.toString(i).getBytes());
            out.write(RequestHandler.REF_TAG_OPEN_END);

            if (wrapper instanceof BeanWrapper && constraints != null) {
                ((BeanWrapper) wrapper).serialize(out, constraints);
            } else {
                wrapper.serialize(out);
            }

            out.write(RequestHandler.REF_TAG_CLOSE);
        }
    }
}