Spring Framework example source code file (FileCopyUtils.java)

This example Spring Framework source code file (FileCopyUtils.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

bufferedinputstream, bytearrayinputstream, could, file, file, fileoutputstream, io, ioexception, ioexception, no, no, outputstream, outputstream, stringwriter, writer

The Spring Framework FileCopyUtils.java source code

/*
 * Copyright 2002-2005 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.util;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Simple utility methods for file and stream copying.
 * All copy methods use a block size of 4096 bytes,
 * and close all affected streams when done.
 *
 * <p>Mainly for use within the framework,
 * but also useful for application code.
 *
 * @author Juergen Hoeller
 * @since 06.10.2003
 */
public abstract class FileCopyUtils {

	private static final Log logger = LogFactory.getLog(FileCopyUtils.class);

	public static final int BUFFER_SIZE = 4096;


	//---------------------------------------------------------------------
	// Copy methods for java.io.File
	//---------------------------------------------------------------------

	/**
	 * Copy the contents of the given input File to the given output File.
	 * @param in the file to copy from
	 * @param out the file to copy to
	 * @return the number of bytes copied
	 * @throws IOException in case of I/O errors
	 */
	public static int copy(File in, File out) throws IOException {
		Assert.notNull(in, "No input File specified");
		Assert.notNull(out, "No output File specified");
		return copy(new BufferedInputStream(new FileInputStream(in)),
		    new BufferedOutputStream(new FileOutputStream(out)));
	}

	/**
	 * Copy the contents of the given byte array to the given output File.
	 * @param in the byte array to copy from
	 * @param out the file to copy to
	 * @throws IOException in case of I/O errors
	 */
	public static void copy(byte[] in, File out) throws IOException {
		Assert.notNull(in, "No input byte array specified");
		Assert.notNull(out, "No output File specified");
		ByteArrayInputStream inStream = new ByteArrayInputStream(in);
		OutputStream outStream = new BufferedOutputStream(new FileOutputStream(out));
		copy(inStream, outStream);
	}

	/**
	 * Copy the contents of the given input File into a new byte array.
	 * @param in the file to copy from
	 * @return the new byte array that has been copied to
	 * @throws IOException in case of I/O errors
	 */
	public static byte[] copyToByteArray(File in) throws IOException {
		Assert.notNull(in, "No input File specified");
		return copyToByteArray(new BufferedInputStream(new FileInputStream(in)));
	}


	//---------------------------------------------------------------------
	// Copy methods for java.io.InputStream / java.io.OutputStream
	//---------------------------------------------------------------------

	/**
	 * Copy the contents of the given InputStream to the given OutputStream.
	 * Closes both streams when done.
	 * @param in the stream to copy from
	 * @param out the stream to copy to
	 * @return the number of bytes copied
	 * @throws IOException in case of I/O errors
	 */
	public static int copy(InputStream in, OutputStream out) throws IOException {
		Assert.notNull(in, "No InputStream specified");
		Assert.notNull(out, "No OutputStream specified");
		try {
			int byteCount = 0;
			byte[] buffer = new byte[BUFFER_SIZE];
			int bytesRead = -1;
			while ((bytesRead = in.read(buffer)) != -1) {
				out.write(buffer, 0, bytesRead);
				byteCount += bytesRead;
			}
			out.flush();
			return byteCount;
		}
		finally {
			try {
				in.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close InputStream", ex);
			}
			try {
				out.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close OutputStream", ex);
			}
		}
	}

	/**
	 * Copy the contents of the given byte array to the given OutputStream.
	 * Closes the stream when done.
	 * @param in the byte array to copy from
	 * @param out the OutputStream to copy to
	 * @throws IOException in case of I/O errors
	 */
	public static void copy(byte[] in, OutputStream out) throws IOException {
		Assert.notNull(in, "No input byte array specified");
		Assert.notNull(out, "No OutputStream specified");
		try {
			out.write(in);
		}
		finally {
			try {
				out.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close OutputStream", ex);
			}
		}
	}

	/**
	 * Copy the contents of the given InputStream into a new byte array.
	 * Closes the stream when done.
	 * @param in the stream to copy from
	 * @return the new byte array that has been copied to
	 * @throws IOException in case of I/O errors
	 */
	public static byte[] copyToByteArray(InputStream in) throws IOException {
		ByteArrayOutputStream out = new ByteArrayOutputStream(BUFFER_SIZE);
		copy(in, out);
		return out.toByteArray();
	}


	//---------------------------------------------------------------------
	// Copy methods for java.io.Reader / java.io.Writer
	//---------------------------------------------------------------------

	/**
	 * Copy the contents of the given Reader to the given Writer.
	 * Closes both when done.
	 * @param in the Reader to copy from
	 * @param out the Writer to copy to
	 * @return the number of characters copied
	 * @throws IOException in case of I/O errors
	 */
	public static int copy(Reader in, Writer out) throws IOException {
		Assert.notNull(in, "No Reader specified");
		Assert.notNull(out, "No Writer specified");
		try {
			int byteCount = 0;
			char[] buffer = new char[BUFFER_SIZE];
			int bytesRead = -1;
			while ((bytesRead = in.read(buffer)) != -1) {
				out.write(buffer, 0, bytesRead);
				byteCount += bytesRead;
			}
			out.flush();
			return byteCount;
		}
		finally {
			try {
				in.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close Reader", ex);
			}
			try {
				out.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close Writer", ex);
			}
		}
	}

	/**
	 * Copy the contents of the given String to the given output Writer.
	 * Closes the write when done.
	 * @param in the String to copy from
	 * @param out the Writer to copy to
	 * @throws IOException in case of I/O errors
	 */
	public static void copy(String in, Writer out) throws IOException {
		Assert.notNull(in, "No input String specified");
		Assert.notNull(out, "No Writer specified");
		try {
			out.write(in);
		}
		finally {
			try {
				out.close();
			}
			catch (IOException ex) {
				logger.warn("Could not close Writer", ex);
			}
		}
	}

	/**
	 * Copy the contents of the given Reader into a String.
	 * Closes the reader when done.
	 * @param in the reader to copy from
	 * @return the String that has been copied to
	 * @throws IOException in case of I/O errors
	 */
	public static String copyToString(Reader in) throws IOException {
		StringWriter out = new StringWriter();
		copy(in, out);
		return out.toString();
	}

}