EncapsulationUtility.java

/*
 * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package org.jboss.com.sun.corba.se.impl.ior;

import java.util.Iterator;
import java.util.List;

import org.jboss.com.sun.corba.se.impl.encoding.CDROutputStream;
import org.jboss.com.sun.corba.se.impl.encoding.EncapsInputStream;
import org.jboss.com.sun.corba.se.impl.encoding.EncapsOutputStream;
import org.jboss.com.sun.corba.se.spi.ior.Identifiable;
import org.jboss.com.sun.corba.se.spi.ior.IdentifiableFactoryFinder;
import org.jboss.com.sun.corba.se.spi.ior.WriteContents;
import org.jboss.com.sun.corba.se.spi.orb.ORB;
import org.omg.CORBA_2_3.portable.InputStream;
import org.omg.CORBA_2_3.portable.OutputStream;

/**
 * This static utility class contains various utility methods for reading and writing CDR encapsulations.
 * 
 * @author Ken Cavanaugh
 */
public class EncapsulationUtility
{
    private EncapsulationUtility()
    {
    }

    /**
     * Read the count from is, then read count Identifiables from is using the factory. Add each constructed
     * Identifiable to container.
     */
    public static void readIdentifiableSequence(List<Object> container, IdentifiableFactoryFinder finder,
            InputStream istr)
    {
        int count = istr.read_long();
        for (int ctr = 0; ctr < count; ctr++)
        {
            int id = istr.read_long();
            Identifiable obj = finder.create(id, istr);
            container.add(obj);
        }
    }

    /**
     * Write all Identifiables that we contain to os. The total length must be written before this method is called.
     */
    public static void writeIdentifiableSequence(List<Object> container, OutputStream os)
    {
        os.write_long(container.size());
        Iterator<Object> iter = container.iterator();
        while (iter.hasNext())
        {
            Identifiable obj = (Identifiable) iter.next();
            os.write_long(obj.getId());
            obj.write(os);
        }
    }

    /**
     * Helper method that is used to extract data from an output stream and write the data to another output stream.
     * Defined as static so that it can be used in another class.
     */
    static public void writeOutputStream(OutputStream dataStream, OutputStream os)
    {
        byte[] data = ((CDROutputStream) dataStream).toByteArray();
        os.write_long(data.length);
        os.write_octet_array(data, 0, data.length);
    }

    /**
     * Helper method to read the octet array from is, deencapsulate it, and return as another InputStream. This must be
     * called inside the constructor of a derived class to obtain the correct stream for unmarshalling data.
     */
    static public InputStream getEncapsulationStream(InputStream is)
    {
        byte[] data = readOctets(is);
        EncapsInputStream result = new EncapsInputStream(is.orb(), data, data.length);
        result.consumeEndian();
        return result;
    }

    /**
     * Helper method that reads an octet array from an input stream. Defined as static here so that it can be used in
     * another class.
     */
    static public byte[] readOctets(InputStream is)
    {
        int len = is.read_ulong();
        byte[] data = new byte[len];
        is.read_octet_array(data, 0, len);
        return data;
    }

    static public void writeEncapsulation(WriteContents obj, OutputStream os)
    {
        EncapsOutputStream out = new EncapsOutputStream((ORB) os.orb());

        out.putEndian();

        obj.writeContents(out);

        writeOutputStream(out, os);
    }
}