IOSystem.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.creadur.tentacles;

import org.apache.commons.io.IOUtils;
import org.apache.logging.log4j.*;
import java.io.*;
import java.net.URL;
import java.nio.file.Files;
import java.util.zip.ZipInputStream;

public class IOSystem {
	private static final Logger LOG = LogManager.getLogger(IOSystem.class);

	public String slurp(final File file) throws IOException {
		final ByteArrayOutputStream out = new ByteArrayOutputStream();
		copy(file, out);
		return out.toString();
	}

	public String slurp(final URL url) throws IOException {
		final ByteArrayOutputStream out = new ByteArrayOutputStream();
		copy(url.openStream(), out);
		return out.toString();
	}

	public void writeString(final File file, final String string) throws IOException {
		final FileWriter out = new FileWriter(file);
		try {
			final BufferedWriter bufferedWriter = new BufferedWriter(out);
			try {
				bufferedWriter.write(string);
				bufferedWriter.newLine();
			} finally {
				close(bufferedWriter);
			}
		} finally {
			close(out);
		}
	}

	private void copy(final File from, final OutputStream to) throws IOException {
		final InputStream read = read(from);
		try {
			copy(read, to);
		} finally {
			close(read);
		}
	}

	public void copy(final InputStream from, final File to) throws IOException {
		final OutputStream write = write(to);
		try {
			copy(from, write);
		} finally {
			close(write);
		}
	}

	private void copy(final InputStream from, final OutputStream to) throws IOException {
		IOUtils.copy(from, to);
	}

	public void copy(final byte[] from, final File to) throws IOException {
		copy(new ByteArrayInputStream(from), to);
	}

	public ZipInputStream unzip(final File file) throws IOException {
		final InputStream read = read(file);
		return new ZipInputStream(read);
	}

	public void close(final Closeable closeable) {
		if (closeable == null) {
			return;
		}
		try {
			if (closeable instanceof Flushable) {
				((Flushable) closeable).flush();
			}
		} catch (final IOException e) {
            LOG.trace("Error when trying to flush before closing {}", closeable, e);
		}
		try {
			closeable.close();
		} catch (final IOException e) {
            LOG.trace("Error when trying to close {}", closeable, e);
		}
	}

	private OutputStream write(final File destination) throws IOException {
		final OutputStream out = Files.newOutputStream(destination.toPath());
		return new BufferedOutputStream(out, 32768);
	}

	public InputStream read(final File source) throws IOException {
		final InputStream in = Files.newInputStream(source.toPath());
		return new BufferedInputStream(in, 32768);
	}

	public byte[] read(final InputStream in) throws IOException {
		final ByteArrayOutputStream out = new ByteArrayOutputStream();
		copy(in, out);
		out.close();
		return out.toByteArray();
	}
}