VFS-2.0-RC1/sandbox/src/main/java/org/apache/commons/vfs/provider/mime/MimeAttributesMap.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file 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 with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, 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.
 */
package org.apache.commons.vfs.provider.mime;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.mail.Header;
import javax.mail.MessagingException;
import javax.mail.Part;
import javax.mail.Address;
import javax.mail.internet.MimeMessage;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

/**
 * A map which tries to allow access to the various aspects of the mail
 */
public class MimeAttributesMap implements Map
{
    private Log log = LogFactory.getLog(MimeAttributesMap.class);

    private final static String OBJECT_PREFIX = "obj.";

    private final Part part;
    private Map backingMap;

    private final Map mimeMessageGetters = new TreeMap();

    public MimeAttributesMap(Part part)
    {
        this.part = part;
        addMimeMessageMethod(part.getClass().getMethods());
        addMimeMessageMethod(part.getClass().getDeclaredMethods());
    }

    private void addMimeMessageMethod(Method[] methods)
    {
        for (int i = 0; i < methods.length; i++)
        {
            Method method = methods[i];
            if (!Modifier.isPublic(method.getModifiers()))
            {
                continue;
            }
            if (method.getParameterTypes().length > 0)
            {
                continue;
            }

            if (method.getName().startsWith("get"))
            {
                mimeMessageGetters.put(method.getName().substring(3), method);
            }
            else if (method.getName().startsWith("is"))
            {
                mimeMessageGetters.put(method.getName().substring(2), method);
            }
        }
    }

    private Map getMap()
    {
        if (backingMap == null)
        {
            backingMap = createMap();
        }

        return backingMap;
    }

    private Map createMap()
    {
        Map ret = new TreeMap();

        Enumeration headers;
        try
        {
            headers = part.getAllHeaders();
        }
        catch (MessagingException e)
        {
            throw new RuntimeException(e);
        }

        // add all headers
        while (headers.hasMoreElements())
        {
            Header header = (Header) headers.nextElement();
            String headerName = header.getName();

            Object values = ret.get(headerName);

            if (values == null)
            {
                ret.put(headerName, header.getValue());
            }
            else if (values instanceof String)
            {
                List newValues = new ArrayList();
                newValues.add(values);
                newValues.add(header.getValue());
                ret.put(headerName, newValues);
            }
            else if (values instanceof List)
            {
                ((List) values).add(header.getValue());
            }
        }

        // add all simple get/is results (with obj. prefix)
        Iterator iterEntries = mimeMessageGetters.entrySet().iterator();
        while (iterEntries.hasNext())
        {
            Map.Entry entry = (Map.Entry) iterEntries.next();
            String name = (String) entry.getKey();
            Method method = (Method) entry.getValue();

            try
            {
                Object value = method.invoke(part, null);
                ret.put(OBJECT_PREFIX + name, value);
            }
            catch (IllegalAccessException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
            catch (InvocationTargetException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
        }

        // add extended fields (with obj. prefix too)
        if (part instanceof MimeMessage)
        {
            MimeMessage message = (MimeMessage) part;
            try
            {
                Address[] address = message.getRecipients(MimeMessage.RecipientType.BCC);
                ret.put(OBJECT_PREFIX + "Recipients.BCC", address);
            }
            catch (MessagingException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
            try
            {
                Address[] address = message.getRecipients(MimeMessage.RecipientType.CC);
                ret.put(OBJECT_PREFIX + "Recipients.CC", address);
            }
            catch (MessagingException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
            try
            {
                Address[] address = message.getRecipients(MimeMessage.RecipientType.TO);
                ret.put(OBJECT_PREFIX + "Recipients.TO", address);
            }
            catch (MessagingException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
            try
            {
                Address[] address = message.getRecipients(MimeMessage.RecipientType.NEWSGROUPS);
                ret.put(OBJECT_PREFIX + "Recipients.NEWSGROUPS", address);
            }
            catch (MessagingException e)
            {
                log.debug(e.getLocalizedMessage(), e);
            }
        }

        return ret;
    }

    public int size()
    {
        return getMap().size();
    }

    public boolean isEmpty()
    {
        return getMap().size() < 1;
    }

    public boolean containsKey(Object key)
    {
        return getMap().containsKey(key);
    }

    public boolean containsValue(Object value)
    {
        return getMap().containsValue(value);
    }

    public Object get(Object key)
    {
        return getMap().get(key);
    }

    public Object put(Object key, Object value)
    {
        throw new UnsupportedOperationException();
    }

    public Object remove(Object key)
    {
        throw new UnsupportedOperationException();
    }

    public void putAll(Map t)
    {
        throw new UnsupportedOperationException();
    }

    public void clear()
    {
        throw new UnsupportedOperationException();
    }

    public Set keySet()
    {
        return Collections.unmodifiableSet(getMap().keySet());
    }

    public Collection values()
    {
        return Collections.unmodifiableCollection(getMap().values());
    }

    public Set entrySet()
    {
        return Collections.unmodifiableSet(getMap().entrySet());
    }
}