/*
    * $Author: stuelten $
    * $Id: IOHelper.java 18 2007-05-08 21:49:53Z stuelten $ 
    */
   package net.sf.jlayercheck.util.io;
   
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStream;
  import java.io.Reader;
  import java.io.StringWriter;
  import java.io.Writer;
  import java.net.URL;
  
  /**
   * Some helper methods for file and io handling.
   * 
   * @author timo
   * @author $Author: stuelten $
   * @version $Id: IOHelper.java 18 2007-05-08 21:49:53Z stuelten $
   */
  public class IOHelper {
  
  	/** Buffer size for IO. 2KB for most systems. */
  	public static final int BUFFER_SIZE = 2048;
  
  	/**
  	 * Close stream, catching all exceptions.
  	 * 
  	 * @param stream
  	 */
  	public static void close(OutputStream stream) {
  		if (stream != null) {
  			try {
  				stream.close();
  			} catch (IOException e) {
  				// Ignore
  			}
  		}
  	}
  
  	/**
  	 * Close stream, catching all exceptions.
  	 * 
  	 * @param stream
  	 */
  	public static void close(InputStream stream) {
  		if (stream != null) {
  			try {
  				stream.close();
  			} catch (IOException e) {
  				// Ignore
  			}
  		}
  	}
  
  	/**
  	 * Close reader, catching all exceptions.
  	 * 
  	 * @param reader
  	 */
  	public static void close(Reader reader) {
  		if (reader != null) {
  			try {
  				reader.close();
  			} catch (IOException e) {
  				// Ignore
  			}
  		}
  	}
  
  	/**
  	 * Close writer, catching all exceptions.
  	 * 
  	 * @param writer
  	 */
  	public static void close(Writer writer) {
  		if (writer != null) {
  			try {
  				writer.close();
  			} catch (IOException e) {
  				// Ignore
  			}
  		}
  	}
  
  	// ----------------------------------------------------------------------
  
  	/**
  	 * Copy content from in to out.
  	 * 
  	 * @param in
  	 *            The stream to read from
  	 * @param out
  	 *            The stream to write to
 	 * @throws IOException
 	 */
 	public static void copy(InputStream in, OutputStream out)
 			throws IOException {
 		byte[] buffer = new byte[BUFFER_SIZE];
 		int len = in.read(buffer);
 		while (len > 0) {
 			out.write(buffer, 0, len);
 			len = in.read(buffer);
 		}
 	}
 
 	/**
 	 * Copy content from in to out.
 	 * 
 	 * @param in
 	 *            The reader to read from
 	 * @param out
 	 *            The writer to write to
 	 * @throws IOException
 	 */
 	public static void copy(Reader in, Writer out) throws IOException {
 		char[] buffer = new char[BUFFER_SIZE];
 		int len = in.read(buffer);
 		while (len > 0) {
 			out.write(buffer, 0, len);
 			len = in.read(buffer);
 		}
 	}
 
 	/**
 	 * Copy file to another file
 	 * 
 	 * @param from
 	 *            source file
 	 * @param to
 	 *            destination file
 	 */
 	public static void copy(File from, File to) {
 		FileInputStream in = null;
 		FileOutputStream out = null;
 		try {
 			in = new FileInputStream(from);
 			out = new FileOutputStream(to);
 		} catch (IOException e) {
 			throw new RuntimeException("Error copying " + from + " to " + to, e);
 		} finally {
 			close(in);
 			close(out);
 		}
 	}
 
 	/**
 	 * Copy content from URL to a file
 	 * 
 	 * @param from
 	 *            source
 	 * @param to
 	 *            destination file
 	 */
 	public static void copy(URL from, File to) {
 		InputStream in = null;
 		FileOutputStream out = null;
 		try {
 			in = from.openStream();
 			out = new FileOutputStream(to);
 		} catch (IOException e) {
 			throw new RuntimeException("Error copying " + from + " to " + to, e);
 		} finally {
 			close(in);
 			close(out);
 		}
 	}
 
 	// ----------------------------------------------------------------------
 
 	/**
 	 * Read content from URL into string.
 	 * 
 	 * @param url
 	 *            URL to read
 	 * @return a String containing complete content
 	 */
 	public static String readContent(URL url) {
 		StringWriter writer = new StringWriter();
 		Reader reader = null;
 		try {
 			reader = new InputStreamReader(url.openStream());
 			copy(reader, writer);
 		} catch (IOException e) {
 			throw new RuntimeException("Cannot read " + url, e);
 		} finally {
 			close(reader);
 		}
 		return writer.toString();
 	}
 
 }