/**
* Copyright 2011-2014 Asakusa Framework Team.
*
* 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.asakusafw.windgate.stream.file;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.Arrays;
import java.util.Iterator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.asakusafw.windgate.stream.CountingInputStream;
import com.asakusafw.windgate.stream.InputStreamProvider;
/**
* An implementation of {@link InputStreamProvider} using files.
* @since 0.2.4
*/
public class FileInputStreamProvider extends InputStreamProvider {
static final Logger LOG = LoggerFactory.getLogger(FileInputStreamProvider.class);
private static final int BUFFER_SIZE = 1024 * 64;
private final Iterator<File> iterator;
private File current;
/**
* Creates a new instance.
* @param file target file to open
* @throws IllegalArgumentException if some parameters were {@code null}
*/
public FileInputStreamProvider(File file) {
if (file == null) {
throw new IllegalArgumentException("file must not be null"); //$NON-NLS-1$
}
this.iterator = Arrays.asList(file).iterator();
}
@Override
public boolean next() throws IOException {
current = null;
if (iterator.hasNext()) {
current = iterator.next().getCanonicalFile();
return true;
} else {
return false;
}
}
@Override
public String getCurrentPath() {
return current.getAbsolutePath();
}
@Override
public CountingInputStream openStream() throws IOException {
LOG.debug("Opening file to read: {}",
current);
boolean succeed = false;
FileInputStream stream = new FileInputStream(current);
try {
CountingInputStream result = new CountingInputStream(new BufferedInputStream(stream, BUFFER_SIZE));
succeed = true;
return result;
} finally {
if (succeed == false) {
try {
stream.close();
} catch (IOException e) {
if (LOG.isDebugEnabled()) {
LOG.debug(MessageFormat.format(
"Failed to dispose input: {0}",
current), e);
}
}
}
}
}
@Override
public void close() {
return;
}
}