IndentingOutputStream.java
/*
** Module : IndentingOutputStream.java
** Abstract : allows caller-controlled indenting of output
**
** Copyright (c) 2007-2017, Golden Code Development Corporation.
**
** -#- -I- --Date-- -T- --JPRM-- ----------------Description-----------------
** 001 GES 20070711 NEW @34476 Created initial version which allows
** caller-controlled indenting of output.
** 002 GES 20080318 CHG @37539 Moved pad handling to a separate class.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program 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 Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
** Under Section 7 of the GNU Affero GPL version 3, the following additional
** terms apply to the works covered under the License. These additional terms
** are non-permissive additional terms allowed under Section 7 of the GNU
** Affero GPL version 3 and may not be removed by you.
**
** 0. Attribution Requirement.
**
** You must preserve all legal notices or author attributions in the covered
** work or Appropriate Legal Notices displayed by works containing the covered
** work. You may not remove from the covered work any author or developer
** credit already included within the covered work.
**
** 1. No License To Use Trademarks.
**
** This license does not grant any license or rights to use the trademarks
** Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
** of Golden Code Development Corporation. You are not authorized to use the
** name Golden Code, FWD, or the names of any author or contributor, for
** publicity purposes without written authorization.
**
** 2. No Misrepresentation of Affiliation.
**
** You may not represent yourself as Golden Code Development Corporation or FWD.
**
** You may not represent yourself for publicity purposes as associated with
** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
** 3. No Misrepresentation of Source or Origin.
**
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** versions of the covered work must be marked in a reasonable way to make it
** clear that the modified work is not originating from Golden Code Development
** Corporation or FWD. All modified versions must contain the notices of
** attribution required in this license.
*/
package com.goldencode.p2j.io;
import java.io.*;
/**
* Provides <code>OutputStream</code> semantics with caller-controlled
* indenting. An indent is written (inserted) between each newline and any
* subsequent (non-newline) bytes that are written.
* <p>
* This class is not thread-safe.
*
* @author GES
*/
public class IndentingOutputStream
extends FilterOutputStream
implements Indentable
{
/** Indent state manager. */
private Indentable indent = new IndentHandler();
/** The last byte written to the stream. */
private byte last = (byte) '\n';
/**
* Creates an instance with the associated output stream as the base and
* a default 0 indent level.
*
* @param out
* The stream on which we filter.
*/
public IndentingOutputStream(OutputStream out)
{
super(out);
}
/**
* Creates an instance with the associated output stream as the base.
*
* @param out
* The stream on which we filter.
* @param indent
* The initial indent level.
*/
public IndentingOutputStream(OutputStream out, int indent)
{
this(out);
setIndent(indent);
}
/**
* Accesses the current indent level.
*
* @return Indent level.
*/
public int getIndent()
{
return indent.getIndent();
}
/**
* Sets the current indent level.
*
* @param indent
* New indent level.
*/
public void setIndent(int indent)
{
this.indent.setIndent(indent);
}
/**
* Increments the indent level by 1.
*/
public void increment()
{
indent.increment();
}
/**
* Decrements the indent level by 1.
*/
public void decrement()
{
indent.decrement();
}
/**
* Accesses the number of spaces in a single indent level.
*
* @return Width of each indent level.
*/
public int getWidth()
{
return indent.getWidth();
}
/**
* Sets the number of spaces in a single indent level.
*
* @param width
* New indent width.
*/
public void setWidth(int width)
{
indent.setWidth(width);
}
/**
* Get the current pad.
*
* @return The pad string for the next line of output.
*/
public String getPad()
{
return indent.getPad();
}
/**
* Sets both the indent level and the number of spaces in a single indent
* level. This is a convenience function to avoid 2 separate calls and
* the small amount of shared overhead that would have been incurred in
* those calls.
*
* @param indent
* New indent level.
* @param width
* New indent width.
*/
public void setPad(int indent, int width)
{
this.indent.setPad(indent, width);
}
/**
* Writes the specified byte to this output stream (only the low order 8
* bits are written, the high order 24 bits are ignored).
* <p>
* The current pad is inserted into the stream between all newline
* characters and any subsequent non-newline bytes.
*
* @param b
* The byte to write.
*
* @throws IOException
* If an I/O error occurs. In particular, an IOException may be
* thrown if the output stream has been closed.
*/
public void write(int b)
throws IOException
{
write(new byte[] { (byte) b });
}
/**
* Writes the entire contents of the specified byte array to this output
* stream.
* <p>
* The current pad is inserted into the stream between all newline
* characters and any subsequent non-newline bytes.
*
* @param b
* The byte array to write.
*
* @throws IOException
* If an I/O error occurs. In particular, an IOException may be
* thrown if the output stream has been closed.
* @throws NullPointerException
* If the array is <code>null</code>.
*/
public void write(byte[] b)
throws IOException,
NullPointerException
{
write(b, 0, b.length);
}
/**
* Writes <code>len</code> bytes from the specified byte array starting
* at offset <code>off</code> in this output stream. Element b[off] is
* the first byte written and b[off+len-1] is the last byte written.
* <p>
* The current pad is inserted into the stream between all newline
* characters and any subsequent non-newline bytes.
*
* @param b
* The array of bytes to write.
* @param off
* The start offset in the array.
* @param len
* The number of bytes to write.
*
* @throws IOException
* If an I/O error occurs. In particular, an IOException may be
* thrown if the output stream has been closed.
*
* @throws NullPointerException
* If the array is <code>null</code>.
* @throws IndexOutOfBoundsException
* If the offset or length are negative, or if offset + length
* is larger than the length of the array.
*/
public void write(byte[] b, int off, int len)
throws IOException,
NullPointerException,
IndexOutOfBoundsException
{
boolean empty = (indent.getIndent() == 0 && indent.getWidth() == 0);
if (empty)
{
// no identing needed, use faster approach
out.write(b, off, len);
// remember the last char
last = b[off + len - 1];
}
else
{
// indent needed, process one byte at a time
for (int i = 0; i < len; i++)
{
byte next = b[i + off];
// look for an output of a non-newline that follows a newline
if (last == '\n' && next != '\n')
{
// insert the indent
out.write(indent.getPad().getBytes());
}
// write the current character
out.write(next);
// update the last character
last = next;
}
}
}
}