mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-27 00:09:58 +08:00
298 lines
8.7 KiB
Java
298 lines
8.7 KiB
Java
/* CharArrayWriter.java -- Write chars to a buffer
|
|
Copyright (C) 1998, 1999, 2001 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.io;
|
|
|
|
/**
|
|
* This class allows data to be written to a char array buffer and
|
|
* and then retrieved by an application. The internal char array
|
|
* buffer is dynamically resized to hold all the data written. Please
|
|
* be aware that writing large amounts to data to this stream will
|
|
* cause large amounts of memory to be allocated.
|
|
* <p>
|
|
* The size of the internal buffer defaults to 32 and it is resized
|
|
* in increments of 1024 chars. This behavior can be over-ridden by using the
|
|
* following two properties:
|
|
* <p>
|
|
* <ul>
|
|
* <li><xmp>gnu.java.io.CharArrayWriter.initialBufferSize</xmp>
|
|
* <li><xmp>gnu.java.io.CharArrayWriter.bufferIncrementSize</xmp>
|
|
* </ul>
|
|
* <p>
|
|
* There is a constructor that specified the initial buffer size and
|
|
* that is the preferred way to set that value because it it portable
|
|
* across all Java class library implementations.
|
|
* <p>
|
|
*
|
|
* @author Aaron M. Renn (arenn@urbanophile.com)
|
|
* @author Tom Tromey <tromey@cygnus.com>
|
|
*/
|
|
public class CharArrayWriter extends Writer
|
|
{
|
|
/**
|
|
* The default initial buffer size
|
|
*/
|
|
private static final int DEFAULT_INITIAL_BUFFER_SIZE = 32;
|
|
|
|
/**
|
|
* This method initializes a new <code>CharArrayWriter</code> with
|
|
* the default buffer size of 32 chars. If a different initial
|
|
* buffer size is desired, see the constructor
|
|
* <code>CharArrayWriter(int size)</code>.
|
|
*/
|
|
public CharArrayWriter ()
|
|
{
|
|
this (DEFAULT_INITIAL_BUFFER_SIZE);
|
|
}
|
|
|
|
/**
|
|
* This method initializes a new <code>CharArrayWriter</code> with
|
|
* a specified initial buffer size.
|
|
*
|
|
* @param size The initial buffer size in chars
|
|
*/
|
|
public CharArrayWriter (int size)
|
|
{
|
|
super ();
|
|
buf = new char[size];
|
|
}
|
|
|
|
/**
|
|
* Closes the stream. This method is guaranteed not to free the contents
|
|
* of the internal buffer, which can still be retrieved.
|
|
*/
|
|
public void close ()
|
|
{
|
|
closed = true;
|
|
}
|
|
|
|
/**
|
|
* This method flushes all buffered chars to the stream.
|
|
*/
|
|
public void flush () throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (closed)
|
|
throw new IOException ("Stream closed");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method discards all of the chars that have been written to the
|
|
* internal buffer so far by setting the <code>count</code> variable to
|
|
* 0. The internal buffer remains at its currently allocated size.
|
|
*/
|
|
public void reset ()
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
count = 0;
|
|
// Allow this to reopen the stream.
|
|
// FIXME - what does the JDK do?
|
|
closed = false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method returns the number of chars that have been written to
|
|
* the buffer so far. This is the same as the value of the protected
|
|
* <code>count</code> variable. If the <code>reset</code> method is
|
|
* called, then this value is reset as well. Note that this method does
|
|
* not return the length of the internal buffer, but only the number
|
|
* of chars that have been written to it.
|
|
*
|
|
* @return The number of chars in the internal buffer
|
|
*
|
|
* @see reset
|
|
*/
|
|
public int size ()
|
|
{
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* This method returns a char array containing the chars that have been
|
|
* written to this stream so far. This array is a copy of the valid
|
|
* chars in the internal buffer and its length is equal to the number of
|
|
* valid chars, not necessarily to the the length of the current
|
|
* internal buffer. Note that since this method allocates a new array,
|
|
* it should be used with caution when the internal buffer is very large.
|
|
*/
|
|
public char[] toCharArray ()
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
char[] nc = new char[count];
|
|
System.arraycopy(buf, 0, nc, 0, count);
|
|
return nc;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the chars in the internal array as a <code>String</code>. The
|
|
* chars in the buffer are converted to characters using the system default
|
|
* encoding. There is an overloaded <code>toString()</code> method that
|
|
* allows an application specified character encoding to be used.
|
|
*
|
|
* @return A <code>String</code> containing the data written to this
|
|
* stream so far
|
|
*/
|
|
public String toString ()
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
return new String (buf, 0, count);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method writes the writes the specified char into the internal
|
|
* buffer.
|
|
*
|
|
* @param oneChar The char to be read passed as an int
|
|
*/
|
|
public void write (int oneChar) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (closed)
|
|
throw new IOException ("Stream closed");
|
|
|
|
resize (1);
|
|
buf[count++] = (char) oneChar;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method writes <code>len</code> chars from the passed in array
|
|
* <code>buf</code> starting at index <code>offset</code> into that buffer
|
|
*
|
|
* @param buffer The char array to write data from
|
|
* @param offset The index into the buffer to start writing data from
|
|
* @param len The number of chars to write
|
|
*/
|
|
public void write (char[] buffer, int offset, int len) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (closed)
|
|
throw new IOException ("Stream closed");
|
|
|
|
if (len >= 0)
|
|
resize (len);
|
|
System.arraycopy(buffer, offset, buf, count, len);
|
|
count += len;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method writes <code>len</code> chars from the passed in
|
|
* <code>String</code> <code>buf</code> starting at index
|
|
* <code>offset</code> into the internal buffer.
|
|
*
|
|
* @param str The <code>String</code> to write data from
|
|
* @param offset The index into the string to start writing data from
|
|
* @param len The number of chars to write
|
|
*/
|
|
public void write (String str, int offset, int len) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
if (closed)
|
|
throw new IOException ("Stream closed");
|
|
|
|
if (len >= 0)
|
|
resize (len);
|
|
str.getChars(offset, offset + len, buf, count);
|
|
count += len;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This method writes all the chars that have been written to this stream
|
|
* from the internal buffer to the specified <code>Writer</code>.
|
|
*
|
|
* @param out The <code>Writer</code> to write to
|
|
*
|
|
* @exception IOException If an error occurs
|
|
*/
|
|
public void writeTo (Writer out) throws IOException
|
|
{
|
|
synchronized (lock)
|
|
{
|
|
out.write(buf, 0, count);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* This private method makes the buffer bigger when we run out of room
|
|
* by allocating a larger buffer and copying the valid chars from the
|
|
* old array into it. This is obviously slow and should be avoided by
|
|
* application programmers by setting their initial buffer size big
|
|
* enough to hold everything if possible.
|
|
*/
|
|
private final void resize (int len)
|
|
{
|
|
if (count + len >= buf.length)
|
|
{
|
|
int newlen = buf.length * 2;
|
|
if (count + len > newlen)
|
|
newlen = count + len;
|
|
char[] newbuf = new char[newlen];
|
|
System.arraycopy(buf, 0, newbuf, 0, count);
|
|
buf = newbuf;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* The internal buffer where the data written is stored
|
|
*/
|
|
protected char[] buf;
|
|
|
|
/**
|
|
* The number of chars that have been written to the buffer
|
|
*/
|
|
protected int count;
|
|
|
|
/**
|
|
* True if the stream has been closed.
|
|
*/
|
|
private boolean closed;
|
|
}
|