com.foo.bar.si.file.demo.starter.TransformationHandler.java Source code

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Here is the source code for com.foo.bar.si.file.demo.starter.TransformationHandler.java

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/*
 * Copyright 2014 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
 *
 *      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.foo.bar.si.file.demo.starter;

import java.io.File;
import java.io.IOException;
import java.util.Locale;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.FilenameUtils;
import org.springframework.integration.annotation.Transformer;
import org.springframework.integration.file.FileHeaders;
import org.springframework.integration.support.MessageBuilder;
import org.springframework.messaging.Message;

/**
 * This Spring Integration transformation handler takes the input file, converts
 * the file into a string, converts the file contents into an upper-case string
 * and then sets a few Spring Integration message headers.
 *
 * @author Tarak AKIK
 * @since 1.0
 */
public class TransformationHandler {

    /**
     * Actual Spring Integration transformation handler.
     *
     * @param inputMessage Spring Integration input message
     * @return New Spring Integration message with updated headers
     */
    @Transformer
    public Message<String> handleFile(final Message<File> inputMessage) {

        final File inputFile = inputMessage.getPayload();
        final String filename = inputFile.getName();
        final String fileExtension = FilenameUtils.getExtension(filename);

        final String inputAsString;

        try {
            inputAsString = FileUtils.readFileToString(inputFile);
        } catch (IOException e) {
            throw new IllegalStateException(e);
        }

        final Message<String> message = MessageBuilder.withPayload(inputAsString.toUpperCase(Locale.ENGLISH))
                .setHeader(FileHeaders.FILENAME, filename).setHeader(FileHeaders.ORIGINAL_FILE, inputFile)
                .setHeader("file_size", inputFile.length()).setHeader("file_extension", fileExtension).build();

        return message;
    }
}