ioutils.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

	 * This method uses {@link String#String(char[])} and {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the char array to write, do not modify during output, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(char[] data, OutputStream output) throws IOException
	{
		if (data != null)
		{
			output.write(new String(data).getBytes());
		}
	}

	/**
	 * Writes chars from a <code>char[]</code> to bytes on an <code>OutputStream</code> using
	 * the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#String(char[])} and {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the char array to write, do not modify during output, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(char[] data, OutputStream output, String encoding) throws IOException
	{
		if (data != null)
		{
			if (encoding == null)
			{
				write(data, output);
			}
			else
			{
				output.write(new String(data).getBytes(encoding));
			}
		}
	}

	// write String
	// -----------------------------------------------------------------------
	/**
	 * Writes chars from a <code>String</code> to a <code>Writer</code>.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(String data, Writer output) throws IOException
	{
		if (data != null)
		{
			output.write(data);
		}
	}

	/**
	 * Writes chars from a <code>String</code> to bytes on an <code>OutputStream</code> using
	 * the default character encoding of the platform.
	 * <p>
	 * This method uses {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(String data, OutputStream output) throws IOException
	{
		if (data != null)
		{
			output.write(data.getBytes());
		}
	}

	/**
	 * Writes chars from a <code>String</code> to bytes on an <code>OutputStream</code> using
	 * the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the <code>String</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(String data, OutputStream output, String encoding) throws IOException
	{
		if (data != null)
		{
			if (encoding == null)
			{
				write(data, output);
			}
			else
			{
				output.write(data.getBytes(encoding));
			}
		}
	}

	// write AppendingStringBuffer
	// -----------------------------------------------------------------------
	/**
	 * Writes chars from a <code>AppendingStringBuffer</code> to a <code>Writer</code>.
	 * 
	 * @param data
	 *            the <code>AppendingStringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(StringBuffer data, Writer output) throws IOException
	{
		if (data != null)
		{
			output.write(data.toString());
		}
	}

	/**
	 * Writes chars from a <code>AppendingStringBuffer</code> to bytes on an
	 * <code>OutputStream</code> using the default character encoding of the platform.
	 * <p>
	 * This method uses {@link String#getBytes()}.
	 * 
	 * @param data
	 *            the <code>AppendingStringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(StringBuffer data, OutputStream output) throws IOException
	{
		if (data != null)
		{
			output.write(data.toString().getBytes());
		}
	}

	/**
	 * Writes chars from a <code>AppendingStringBuffer</code> to bytes on an
	 * <code>OutputStream</code> using the specified character encoding.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link String#getBytes(String)}.
	 * 
	 * @param data
	 *            the <code>AppendingStringBuffer</code> to write, null ignored
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void write(StringBuffer data, OutputStream output, String encoding)
			throws IOException
	{
		if (data != null)
		{
			if (encoding == null)
			{
				write(data, output);
			}
			else
			{
				output.write(data.toString().getBytes(encoding));
			}
		}
	}

	// copy from InputStream
	// -----------------------------------------------------------------------
	/**
	 * Copy bytes from an <code>InputStream</code> to an <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static int copy(InputStream input, OutputStream output) throws IOException
	{
		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
		int count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer)))
		{
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a <code>Writer</code> using the
	 * default character encoding of the platform.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void copy(InputStream input, Writer output) throws IOException
	{
		InputStreamReader in = new InputStreamReader(input);
		copy(in, output);
	}

	/**
	 * Copy bytes from an <code>InputStream</code> to chars on a <code>Writer</code> using the
	 * specified character encoding.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * This method uses {@link InputStreamReader}.
	 * 
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void copy(InputStream input, Writer output, String encoding) throws IOException
	{
		if (encoding == null)
		{
			copy(input, output);
		}
		else
		{
			InputStreamReader in = new InputStreamReader(input, encoding);
			copy(in, output);
		}
	}

	// copy from Reader
	// -----------------------------------------------------------------------
	/**
	 * Copy chars from a <code>Reader</code> to a <code>Writer</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>Writer</code> to write to
	 * @return the number of characters copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static int copy(Reader input, Writer output) throws IOException
	{
		char[] buffer = new char[DEFAULT_BUFFER_SIZE];
		int count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer)))
		{
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}

	/**
	 * Copy chars from a <code>Reader</code> to bytes on an <code>OutputStream</code> using the
	 * default character encoding of the platform, and calling flush.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Due to the implementation of OutputStreamWriter, this method performs a flush.
	 * <p>
	 * This method uses {@link OutputStreamWriter}.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void copy(Reader input, OutputStream output) throws IOException
	{
		OutputStreamWriter out = new OutputStreamWriter(output);
		copy(input, out);
		out.flush();
	}

	/**
	 * Copy chars from a <code>Reader</code> to bytes on an <code>OutputStream</code> using the
	 * specified character encoding, and calling flush.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedReader</code>.
	 * <p>
	 * Character encoding names can be found at <a
	 * href="http://www.iana.org/assignments/character-sets">IANA</a>.
	 * <p>
	 * Due to the implementation of OutputStreamWriter, this method performs a flush.
	 * <p>
	 * This method uses {@link OutputStreamWriter}.
	 * 
	 * @param input
	 *            the <code>Reader</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @param encoding
	 *            the encoding to use, null means platform default
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static void copy(Reader input, OutputStream output, String encoding) throws IOException
	{
		if (encoding == null)
		{
			copy(input, output);
		}
		else
		{
			OutputStreamWriter out = new OutputStreamWriter(output, encoding);
			copy(input, out);
			out.flush();
		}
	}

	// content equals
	// -----------------------------------------------------------------------
	/**
	 * Compare the contents of two Streams to determine if they are equal or not.
	 * <p>
	 * This method buffers the input internally using <code>BufferedInputStream</code> if they are
	 * not already buffered.
	 * 
	 * @param input1
	 *            the first stream
	 * @param input2
	 *            the second stream
	 * @return true if the content of the streams are equal or they both don't exist, false
	 *         otherwise
	 * @throws NullPointerException
	 *             if either input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 */
	public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException
	{
		if (!(input1 instanceof BufferedInputStream))
		{
			input1 = new BufferedInputStream(input1);
		}
		if (!(input2 instanceof BufferedInputStream))
		{
			input2 = new BufferedInputStream(input2);
		}

		int ch = input1.read();
		while (-1 != ch)
		{
			int ch2 = input2.read();
			if (ch != ch2)
			{
				return false;
			}
			ch = input1.read();
		}

		int ch2 = input2.read();
		return (ch2 == -1);
	}

	/**
	 * Compare the contents of two Readers to determine if they are equal or not.
	 * <p>
	 * This method buffers the input internally using <code>BufferedReader</code> if they are not
	 * already buffered.
	 * 
	 * @param input1
	 *            the first reader
	 * @param input2
	 *            the second reader
	 * @return true if the content of the readers are equal or they both don't exist, false
	 *         otherwise
	 * @throws NullPointerException
	 *             if either input is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since 1.1
	 */
	public static boolean contentEquals(Reader input1, Reader input2) throws IOException
	{
		if (!(input1 instanceof BufferedReader))
		{
			input1 = new BufferedReader(input1);
		}
		if (!(input2 instanceof BufferedReader))
		{
			input2 = new BufferedReader(input2);
		}

		int ch = input1.read();
		while (-1 != ch)
		{
			int ch2 = input2.read();
			if (ch != ch2)
			{
				return false;
			}
			ch = input1.read();
		}

		int ch2 = input2.read();
		return (ch2 == -1);
	}

}