/*
* Copyright 2002-2014 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 org.springframework.integration.file.transformer;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.Charset;
import org.springframework.util.Assert;
import org.springframework.util.FileCopyUtils;
/**
* A payload transformer that copies a File's contents to a String.
*
* @author Mark Fisher
* @author Gary Russell
*/
public class FileToStringTransformer extends AbstractFilePayloadTransformer<String> {
private volatile Charset charset = Charset.defaultCharset();
/**
* Set the charset name to use when copying the File to a String.
*
* @param charset The charset.
*/
public void setCharset(String charset) {
Assert.notNull(charset, "charset must not be null");
Assert.isTrue(Charset.isSupported(charset), "Charset '" + charset + "' is not supported.");
this.charset = Charset.forName(charset);
}
@Override
protected final String transformFile(File file) throws Exception {
Reader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), this.charset));
return FileCopyUtils.copyToString(reader);
}
}