/*
* Freeplane - mind map editor
* Copyright (C) 2009 Dimitry
*
* This file author is Dimitry
*
* This program 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 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.freeplane.features.url;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
/**
* @author Dimitry Polivaev
* 27.08.2009
*/
public class CleaningInputStream extends InputStream {
private static final int MAX_PUSHED_BACK = 4;
private final PushbackInputStream in;
private int pushedBack = 0;
private boolean isUtf8 = false;
public CleaningInputStream(final InputStream pIn) {
super();
this.in = new PushbackInputStream(pIn, MAX_PUSHED_BACK);
try {
final byte[] bytes = new byte[3];
int i = 0;
int b;
b = in.read();
bytes[i++] = (byte)b;
if(b == 0xef){
b = in.read();
bytes[i++] = (byte)b;
if(b == 0xbb){
b = in.read();
bytes[i++] = (byte)b;
if(b == 0xbf){
isUtf8 = true;
return;
}
}
}
this.in.unread(bytes, 0, i);
pushedBack = i;
}
catch (IOException e) {
}
}
public boolean isUtf8() {
return isUtf8;
}
@Override
public int read() throws IOException {
byte b = (byte) in.read();
if (pushedBack > 0) {
pushedBack--;
return b;
}
if (b == '&') {
final byte[] bytes = new byte[MAX_PUSHED_BACK];
int i = 0;
bytes[i++] = b = (byte) in.read();
if (b == '#') {
bytes[i++] = b = (byte) in.read();
if (b == 'x' || b >= '0' || b <= '3') {
bytes[i++] = (byte) in.read();
bytes[i++] = (byte) in.read();
}
}
if (isValidInput(i, bytes)) {
pushedBack = i;
in.unread(bytes, 0, i);
return '&';
}
else {
return ' ';
}
}
return b;
}
private boolean isValidInput(final int i, final byte[] bytes) {
if (i != MAX_PUSHED_BACK || bytes[i - 1] != ';') {
return true;
}
final int c;
if (bytes[1] == 'x') {
c = Character.digit(bytes[2], 16);
}
else {
c = Character.digit(bytes[1], 10) * 10 + Character.digit(bytes[2], 10);
}
return c >= ' ' || c == '\t' || c == '\r' || c == '\n';
}
}