org.springframework.amqp.support.postprocessor.DelegatingDecompressingPostProcessor.java Source code

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Here is the source code for org.springframework.amqp.support.postprocessor.DelegatingDecompressingPostProcessor.java

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/*
 * Copyright 2014-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.amqp.support.postprocessor;

import java.util.HashMap;
import java.util.Map;

import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.core.Ordered;

/**
 * A {@link MessagePostProcessor} that delegates to one of its {@link MessagePostProcessor}s
 * depending on the content encoding. Supports {@code gzip, zip} by default.
 *
 * @author Gary Russell
 * @since 1.4.2
 */
public class DelegatingDecompressingPostProcessor implements MessagePostProcessor, Ordered {

    private final Map<String, MessagePostProcessor> decompressors = new HashMap<String, MessagePostProcessor>();

    private int order;

    public DelegatingDecompressingPostProcessor() {
        this.decompressors.put("gzip", new GUnzipPostProcessor());
        this.decompressors.put("zip", new UnzipPostProcessor());
    }

    @Override
    public int getOrder() {
        return this.order;
    }

    /**
     * Set the order.
     * @param order the order.
     * @see Ordered
     */
    public void setOrder(int order) {
        this.order = order;
    }

    /**
     * Add a message post processor to the map of decompressing MessageProcessors.
     * @param contentEncoding the content encoding; messages will be decompressed with this post processor
     * if its {@code content-encoding} property matches, or begins with this key followed by ":".
     * @param decompressor the decompressing {@link MessagePostProcessor}.
     */
    public void addDecompressor(String contentEncoding, MessagePostProcessor decompressor) {
        this.decompressors.put(contentEncoding, decompressor);
    }

    /**
     * Remove the decompressor for this encoding; content will not be decompressed even if the
     * {@link org.springframework.amqp.core.MessageProperties#SPRING_AUTO_DECOMPRESS} header is true.
     * @param contentEncoding the content encoding.
     * @return the decompressor if it was present.
     */
    public MessagePostProcessor removeDecompressor(String contentEncoding) {
        return this.decompressors.remove(contentEncoding);
    }

    /**
     * Replace all the decompressors.
     * @param decompressors the decompressors.
     */
    public void setDecompressors(Map<String, MessagePostProcessor> decompressors) {
        this.decompressors.clear();
        this.decompressors.putAll(decompressors);
    }

    @Override
    public Message postProcessMessage(Message message) throws AmqpException {
        String encoding = message.getMessageProperties().getContentEncoding();
        if (encoding == null) {
            return message;
        } else {
            int colonAt = encoding.indexOf(':');
            if (colonAt > 0) {
                encoding = encoding.substring(0, colonAt);
            }
            MessagePostProcessor decompressor = this.decompressors.get(encoding);
            if (decompressor != null) {
                return decompressor.postProcessMessage(message);
            } else {
                return message;
            }
        }
    }

}