com.adaptris.core.services.splitter.MessageSplitterImp.java Source code

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Here is the source code for com.adaptris.core.services.splitter.MessageSplitterImp.java

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/*
 * Copyright 2015 Adaptris Ltd.
 * 
 * Licensed 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 com.adaptris.core.services.splitter;

import java.util.Iterator;

import org.apache.commons.lang.BooleanUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.adaptris.annotation.AdvancedConfig;
import com.adaptris.annotation.InputFieldDefault;
import com.adaptris.core.AdaptrisMessage;
import com.adaptris.core.AdaptrisMessageFactory;
import com.adaptris.core.CoreConstants;

/**
 * Partial implementation of MessageSplitter that handles
 * {@link MessageSplitter#splitMessage(AdaptrisMessage)}.
 *
 * @author lchan
 * @author $Author: lchan $
 */
public abstract class MessageSplitterImp implements MessageSplitter {

    protected transient Logger logR = LoggerFactory.getLogger(this.getClass());

    @AdvancedConfig
    private AdaptrisMessageFactory messageFactory;
    @InputFieldDefault(value = "true")
    private Boolean copyMetadata;
    @InputFieldDefault(value = "false")
    private Boolean copyObjectMetadata;

    public MessageSplitterImp() {
    }

    /**
     * Copy metadata from the parent to the child.
     *
     * @param parent the parent AdaptrisMessage
     * @param child the child AdaptrisMessage
     * @see #setCopyMetadata(Boolean)
     * @see #setCopyObjectMetadata(Boolean)
     */
    protected void copyMetadata(AdaptrisMessage parent, AdaptrisMessage child) {
        if (copyMetadata()) {
            child.setMetadata(parent.getMetadata());
        }
        child.addMetadata(CoreConstants.PARENT_UNIQUE_ID_KEY, parent.getUniqueId());
        if (copyObjectMetadata()) {
            child.getObjectHeaders().putAll(parent.getObjectHeaders());
        }
    }

    /**
     * Select the {@linkplain com.adaptris.core.AdaptrisMessageFactory} instance to use to create new messages.
     *
     * @param msg the AdaptrisMessage to derive the message factory from.
     * @return an {@linkplain com.adaptris.core.AdaptrisMessageFactory} instance
     * @see AdaptrisMessage#getFactory()
     * @see #setMessageFactory(AdaptrisMessageFactory)
     */
    protected AdaptrisMessageFactory selectFactory(AdaptrisMessage msg) {
        /*
         * If the user configured a message factory, use that. We cannot just use the MessageFactory
         * from the message because if that's a FileBackedMessageFactory then the messages resulting from 
         * the split will also be File Backed and we don't want that unless it's explicitly being 
         * configured that way (why would you want that? no-one knows).
         */
        if (getMessageFactory() == null) {
            return msg.getFactory();
        } else {
            return getMessageFactory();
        }
    }

    boolean copyMetadata() {
        return BooleanUtils.toBooleanDefaultIfNull(getCopyMetadata(), true);
    }

    boolean copyObjectMetadata() {
        return BooleanUtils.toBooleanDefaultIfNull(getCopyObjectMetadata(), false);
    }

    /**
     * @return the messageFactory, null if not specified.
     */
    public AdaptrisMessageFactory getMessageFactory() {
        return messageFactory;
    }

    /**
     * Set the message factory used when creating AdaptrisMessage instances.
     *
     * @param f the messageFactory to set
     */
    public void setMessageFactory(AdaptrisMessageFactory f) {
        messageFactory = f;
    }

    /**
     * <p>
     * Sets whether to copy metadata from the original message to the split
     * messages.
     * </p>
     *
     * @param b whether to copy metadata from the original message to the split
     *          messages (default true)
     */
    public void setCopyMetadata(Boolean b) {
        copyMetadata = b;
    }

    /**
     * <p>
     * Returns whether to copy metadata from the original message to the split
     * messages.
     * </p>
     *
     * @return whether to copy metadata from the original message to the split
     *         messages
     */
    public Boolean getCopyMetadata() {
        return copyMetadata;
    }

    public Boolean getCopyObjectMetadata() {
        return copyObjectMetadata;
    }

    /**
     * Whether or not to preserve object metadata to the split messages.
     *
     * @param b true to preserve object metadata (default false)
     */
    public void setCopyObjectMetadata(Boolean b) {
        copyObjectMetadata = b;
    }

    protected abstract class SplitMessageIterator
            implements com.adaptris.core.util.CloseableIterable<AdaptrisMessage>, Iterator<AdaptrisMessage> {
        protected final AdaptrisMessage msg;
        protected final AdaptrisMessageFactory factory;
        private AdaptrisMessage nextMessage;
        private boolean iteratorAvailable = true;

        public SplitMessageIterator(AdaptrisMessage msg, AdaptrisMessageFactory factory) {
            this.msg = msg;
            this.factory = factory;
        }

        @Override
        public Iterator<AdaptrisMessage> iterator() {
            if (!iteratorAvailable) {
                throw new IllegalStateException("iterator() no longer available");
            }
            iteratorAvailable = false;
            return this;
        }

        @Override
        public boolean hasNext() {
            if (nextMessage == null) {
                try {
                    nextMessage = constructAdaptrisMessage();
                } catch (Exception e) {
                    logR.warn("Could not construct next AdaptrisMessage", e);
                    throw new RuntimeException("Could not construct next AdaptrisMessage", e);
                }
            }

            return nextMessage != null;
        }

        @Override
        public AdaptrisMessage next() {
            AdaptrisMessage ret = nextMessage;
            nextMessage = null;
            return ret;
        }

        protected abstract AdaptrisMessage constructAdaptrisMessage() throws Exception;

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

    }
}