src/main/java/org/apache/james/mime4j/message/Multipart.java

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 * distributed with this work for additional information        *
 * regarding copyright ownership.  The ASF licenses this file   *
 * to you under the Apache License, Version 2.0 (the            *
 * "License"); you may not use this file except in compliance   *
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 * software distributed under the License is distributed on an  *
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
 * KIND, either express or implied.  See the License for the    *
 * specific language governing permissions and limitations      *
 * under the License.                                           *
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package org.apache.james.mime4j.message;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.Charset;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import org.apache.james.mime4j.MimeException;
import org.apache.james.mime4j.field.ContentTypeField;
import org.apache.james.mime4j.field.Field;
import org.apache.james.mime4j.util.CharsetUtil;
import org.apache.james.mime4j.util.MessageUtils;

/**
 * Represents a MIME multipart body (see RFC 2045).A multipart body has a 
 * ordered list of body parts. The multipart body also has a preamble and
 * epilogue. The preamble consists of whatever characters appear before the 
 * first body part while the epilogue consists of whatever characters come
 * after the last body part.
 *
 * 
 * @version $Id: Multipart.java,v 1.3 2004/10/02 12:41:11 ntherning Exp $
 */
public class Multipart implements Body {
    private String preamble = "";
    private String epilogue = "";
    private List bodyParts = new LinkedList();
    private Entity parent = null;
    private String subType;

    /**
     * Creates a new empty <code>Multipart</code> instance.
     */
    public Multipart(String subType) {
        this.subType = subType;
    }

    /**
     * Gets the multipart sub-type. E.g. <code>alternative</code> (the default)
     * or <code>parallel</code>. See RFC 2045 for common sub-types and their
     * meaning.
     * 
     * @return the multipart sub-type.
     */
    public String getSubType() {
        return subType;
    }
    
    /**
     * Sets the multipart sub-type. E.g. <code>alternative</code>
     * or <code>parallel</code>. See RFC 2045 for common sub-types and their
     * meaning.
     * 
     * @param subType the sub-type.
     */
    public void setSubType(String subType) {
        this.subType = subType;
    }
    
    /**
     * @see org.apache.james.mime4j.message.Body#getParent()
     */
    public Entity getParent() {
        return parent;
    }
    
    /**
     * @see org.apache.james.mime4j.message.Body#setParent(org.apache.james.mime4j.message.Entity)
     */
    public void setParent(Entity parent) {
        this.parent = parent;
        for (Iterator it = bodyParts.iterator(); it.hasNext();) {
            ((BodyPart) it.next()).setParent(parent);
        }
    }

    /**
     * Gets the epilogue.
     * 
     * @return the epilogue.
     */
    public String getEpilogue() {
        return epilogue;
    }
    
    /**
     * Sets the epilogue.
     * 
     * @param epilogue the epilogue.
     */
    public void setEpilogue(String epilogue) {
        this.epilogue = epilogue;
    }
    
    /**
     * Gets the list of body parts. The list is immutable.
     * 
     * @return the list of <code>BodyPart</code> objects.
     */
    public List getBodyParts() {
        return Collections.unmodifiableList(bodyParts);
    }
    
    /**
     * Sets the list of body parts.
     * 
     * @param bodyParts the new list of <code>BodyPart</code> objects.
     */
    public void setBodyParts(List bodyParts) {
        this.bodyParts = bodyParts;
        for (Iterator it = bodyParts.iterator(); it.hasNext();) {
            ((BodyPart) it.next()).setParent(parent);
        }
    }
    
    /**
     * Adds a body part to the end of the list of body parts.
     * 
     * @param bodyPart the body part.
     */
    public void addBodyPart(BodyPart bodyPart) {
        bodyParts.add(bodyPart);
        bodyPart.setParent(parent);
    }
    
    /**
     * Gets the preamble.
     * 
     * @return the preamble.
     */
    public String getPreamble() {
        return preamble;
    }
    
    /**
     * Sets the preamble.
     * 
     * @param preamble the preamble.
     */
    public void setPreamble(String preamble) {
        this.preamble = preamble;
    }

    /**
     * Write the Multipart to the given OutputStream. 
     * 
     * @param out the OutputStream to write to
     * @param mode compatibility mode
     * 
     * @throws IOException if case of an I/O error
     * @throws MimeException if case of a MIME protocol violation
     */
    public void writeTo(final OutputStream out, int mode) throws IOException, MimeException {
        Entity e = getParent();
        
        ContentTypeField cField = (ContentTypeField) e.getHeader().getField(
                Field.CONTENT_TYPE);
        if (cField == null || cField.getBoundary() == null) {
            throw new MimeException("Multipart boundary not specified");
        }
        String boundary = cField.getBoundary();

        Charset charset = null;
        if (mode == MessageUtils.LENIENT) {
            if (cField != null && cField.getCharset() != null) {
                charset = CharsetUtil.getCharset(cField.getCharset());
            } else {
                charset = MessageUtils.ISO_8859_1;
            }
        } else {
            charset = MessageUtils.DEFAULT_CHARSET;
        }
        
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(out, charset), 8192);
        
        List bodyParts = getBodyParts();

        writer.write(getPreamble());
        writer.write(MessageUtils.CRLF);

        for (int i = 0; i < bodyParts.size(); i++) {
            writer.write("--");
            writer.write(boundary);
            writer.write(MessageUtils.CRLF);
            writer.flush();
            final BodyPart bodyPart = (BodyPart) bodyParts.get(i);
            bodyPart.writeTo(out, mode);
            writer.write(MessageUtils.CRLF);
        }

        writer.write("--");
        writer.write(boundary);
        writer.write("--");
        writer.write(MessageUtils.CRLF);
        final String epilogue = getEpilogue();
        writer.write(epilogue);
        writer.flush();
    }
}