IoUtils.java

/* 
 * Copyright 2003,2004 Peter Lee, Colin Crist
 *
 * 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 hermes.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.charset.Charset;

import org.apache.log4j.Logger;

/**
 * Various utilities for java.io.
 */
public abstract class IoUtils {
	private static final Logger log = Logger.getLogger(IoUtils.class);

	public static void closeQuietly(Reader o) {
		try {
			if (o != null) {
				o.close();
			}
		} catch (IOException e) {
			// NOP
		}
	}

	public static void closeQuietly(Writer o) {
		try {
			if (o != null) {
				o.close();
			}
		} catch (IOException e) {
			// NOP
		}
	}

	public static void closeQuietly(OutputStream o) {
		try {
			if (o != null) {
				o.close();
			}
		} catch (IOException e) {
			// NOP
		}
	}

	public static void closeQuietly(InputStream o) {
		try {
			if (o != null) {
				o.close();
			}
		} catch (IOException e) {
			// NOP
		}
	}

	public static String readFile(File file) throws IOException {
		return readFile(file, Charset.defaultCharset()) ;
	}
	
	public static String readFile(File file, Charset charset) throws IOException {
		FileInputStream stream = new FileInputStream(file);
		try {
			FileChannel fc = stream.getChannel();
			MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
			return charset.decode(bb).toString();
		} finally {
			stream.close();
		}
	}

	public static byte[] readBytes(File f) throws IOException {
		FileInputStream fin = null;
		FileChannel ch = null;
		try {
			fin = new FileInputStream(f);
			ch = fin.getChannel();
			int size = (int) ch.size();
			MappedByteBuffer buf = ch.map(MapMode.READ_ONLY, 0, size);
			byte[] bytes = new byte[size];
			buf.get(bytes);
			return bytes;

		}  finally {
			try {
				if (fin != null) {
					fin.close();
				}
				if (ch != null) {
					ch.close();
				}
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}

	}

	public static String read(File from) throws Exception {

		final FileInputStream istream = new FileInputStream(from);
		final FileChannel channel = istream.getChannel();
		final StringWriter writer = new StringWriter();
		final ByteBuffer buffer = ByteBuffer.allocate(1024 * 1024);
		int read = 0;
		while ((read = channel.read(buffer)) > 0) {
			writer.append(new String(buffer.array(), 0, read));
		}

		return writer.getBuffer().toString();
	}
}