Admin: 1 версия

2010-06-01T07:06:47Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:46Z

Новая страница

== Add a ASCII85 encoding to the stream ==



<source lang="java">

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: ASCII85OutputStream.java 426584 2006-07-28 16:01:47Z jeremias $ */

import java.io.OutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
/**
* This class applies a ASCII85 encoding to the stream.
*
* @version $Id: ASCII85OutputStream.java 426584 2006-07-28 16:01:47Z jeremias $
*/
public class ASCII85OutputStream extends FilterOutputStream
implements ASCII85Constants {
private static final boolean DEBUG = false;
private int pos = 0;
private long buffer = 0;
private int posinline = 0;
private int bw = 0;
/** @see java.io.FilterOutputStream **/
public ASCII85OutputStream(OutputStream out) {
super(out);
}
/** @see java.io.FilterOutputStream **/
public void write(int b) throws IOException {
if (pos == 0) {
buffer += (b << 24) & 0xff000000L;
} else if (pos == 1) {
buffer += (b << 16) & 0xff0000L;
} else if (pos == 2) {
buffer += (b << 8) & 0xff00L;
} else {
buffer += b & 0xffL;
}
pos++;
if (pos > 3) {
checkedWrite(convertWord(buffer));
buffer = 0;
pos = 0;
}
}
/* UNUSED ATM
private void checkedWrite(int b) throws IOException {
if (posinline == 80) {
out.write(EOL); bw++;
posinline = 0;
}
checkedWrite(b);
posinline++;
bw++;
}*/
private void checkedWrite(byte[] buf) throws IOException {
checkedWrite(buf, buf.length, false);
}
private void checkedWrite(byte[] buf, boolean nosplit) throws IOException {
checkedWrite(buf, buf.length, nosplit);
}
private void checkedWrite(byte[] buf , int len) throws IOException {
checkedWrite(buf, len, false);
}
private void checkedWrite(byte[] buf , int len, boolean nosplit) throws IOException {
if (posinline + len > 80) {
int firstpart = (nosplit ? 0 : len - (posinline + len - 80));
if (firstpart > 0) {
out.write(buf, 0, firstpart);
}
out.write(EOL); bw++;
int rest = len - firstpart;
if (rest > 0) {
out.write(buf, firstpart, rest);
}
posinline = rest;
} else {
out.write(buf, 0, len);
posinline += len;
}
bw += len;
}
/**
* This converts a 32 bit value (4 bytes) into 5 bytes using base 85.
* each byte in the result starts with zero at the "!" character so
* the resulting base85 number fits into printable ascii chars
*
* @param word the 32 bit unsigned (hence the long datatype) word
* @return 5 bytes (or a single byte of the "z" character for word
* values of 0)
*/
private byte[] convertWord(long word) {
word = word & 0xffffffff;
if (word == 0) {
return ZERO_ARRAY;
} else {
if (word < 0) {
word = -word;
}
byte c1 =
(byte)((word
/ POW85[0]) & 0xFF);
byte c2 =
(byte)(((word - (c1 * POW85[0]))
/ POW85[1]) & 0xFF);
byte c3 =
(byte)(((word - (c1 * POW85[0])
- (c2 * POW85[1]))
/ POW85[2]) & 0xFF);
byte c4 =
(byte)(((word - (c1 * POW85[0])
- (c2 * POW85[1])
- (c3 * POW85[2]))
/ POW85[3]) & 0xFF);
byte c5 =
(byte)(((word - (c1 * POW85[0])
- (c2 * POW85[1])
- (c3 * POW85[2])
- (c4 * POW85[3])))
& 0xFF);
byte[] ret = {
(byte)(c1 + START), (byte)(c2 + START),
(byte)(c3 + START), (byte)(c4 + START),
(byte)(c5 + START)
};
if (DEBUG) {
for (int i = 0; i < ret.length; i++) {
if (ret[i] < 33 || ret[i] > 117) {
System.out.println("Illegal char value "
+ new Integer(ret[i]));
}
}
}
return ret;
}
}
/** @see Finalizable **/
public void finalizeStream() throws IOException {
// now take care of the trailing few bytes.
// with n leftover bytes, we append 0 bytes to make a full group of 4
// then convert like normal (except not applying the special zero rule)
// and write out the first n+1 bytes from the result
if (pos > 0) {
int rest = pos;
/*
byte[] lastdata = new byte[4];
int i = 0;
for (int j = 0; j < 4; j++) {
if (j < rest) {
lastdata[j] = data[i++];
} else {
lastdata[j] = 0;
}
}
long val = ((lastdata[0] << 24) & 0xff000000L)
+ ((lastdata[1] << 16) & 0xff0000L)
+ ((lastdata[2] << 8) & 0xff00L)
+ (lastdata[3] & 0xffL);
*/
byte[] conv;
// special rule for handling zeros at the end
if (buffer != 0) {
conv = convertWord(buffer);
} else {
conv = new byte[5];
for (int j = 0; j < 5; j++) {
conv[j] = (byte)"!";
}
}
// assert rest+1 <= 5
checkedWrite(conv, rest + 1);
}
// finally write the two character end of data marker
checkedWrite(EOD, true);
flush();

}
/** @see java.io.FilterOutputStream **/
public void close() throws IOException {
finalizeStream();
super.close();
}
}

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: ASCII85Constants.java 426584 2006-07-28 16:01:47Z jeremias $ */

/**
* This interface defines constants used by the ASCII85 filters.
*
* @version $Id: ASCII85Constants.java 426584 2006-07-28 16:01:47Z jeremias $
*/
interface ASCII85Constants {
/** Special character "z" stands for four NULL bytes (short-cut for !!!!!) */
public static final int ZERO = 0x7A; //"z"
/** ZERO as a byte array */
public static final byte[] ZERO_ARRAY = {(byte)ZERO};
/** The start index for ASCII85 characters (!) */
public static final int START = 0x21; //"!"
/** The end index for ASCII85 characters (u) */
public static final int END = 0x75; //"u"
/** The EOL indicator (LF) */
public static final int EOL = 0x0A; //"\n"
/** The EOD (end of data) indicator */
public static final byte[] EOD = {0x7E, 0x3E}; //"~>"
/** Array of powers of 85 (4, 3, 2, 1, 0) */
public static final long POW85[] = new long[] {85 * 85 * 85 * 85,
85 * 85 * 85,
85 * 85,
85,
1};
/*
public static final long BASE85_4 = 85;
public static final long BASE85_3 = BASE85_4 * BASE85_4;
public static final long BASE85_2 = BASE85_3 * BASE85_4;
public static final long BASE85_1 = BASE85_2 * BASE85_4;
*/
}

</source>



== ASCII Utility ==



<source lang="java">

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don"t indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
/*
* @(#)ASCIIUtility.java 1.11 07/05/04
*/
class ASCIIUtility {
// Private constructor so that this class is not instantiated
private ASCIIUtility() { }

/**
* Convert the bytes within the specified range of the given byte
* array into a signed integer in the given radix . The range extends
* from <code>start</code> till, but not including <code>end</code>. 
*
* Based on java.lang.Integer.parseInt()
*/
public static int parseInt(byte[] b, int start, int end, int radix)
throws NumberFormatException {
if (b == null)
throw new NumberFormatException("null");

int result = 0;
boolean negative = false;
int i = start;
int limit;
int multmin;
int digit;
if (end > start) {
if (b[i] == "-") {
negative = true;
limit = Integer.MIN_VALUE;
i++;
} else {
limit = -Integer.MAX_VALUE;
}
multmin = limit / radix;
if (i < end) {
digit = Character.digit((char)b[i++], radix);
if (digit < 0) {
throw new NumberFormatException(
"illegal number: " + toString(b, start, end)
);
} else {
result = -digit;
}
}
while (i < end) {
// Accumulating negatively avoids surprises near MAX_VALUE
digit = Character.digit((char)b[i++], radix);
if (digit < 0) {
throw new NumberFormatException("illegal number");
}
if (result < multmin) {
throw new NumberFormatException("illegal number");
}
result *= radix;
if (result < limit + digit) {
throw new NumberFormatException("illegal number");
}
result -= digit;
}
} else {
throw new NumberFormatException("illegal number");
}
if (negative) {
if (i > start + 1) {
return result;
} else { /* Only got "-" */
throw new NumberFormatException("illegal number");
}
} else {
return -result;
}
}
/**
* Convert the bytes within the specified range of the given byte
* array into a signed integer . The range extends from
* <code>start</code> till, but not including <code>end</code>. 
*/
public static int parseInt(byte[] b, int start, int end)
throws NumberFormatException {
return parseInt(b, start, end, 10);
}
/**
* Convert the bytes within the specified range of the given byte
* array into a signed long in the given radix . The range extends
* from <code>start</code> till, but not including <code>end</code>. 
*
* Based on java.lang.Long.parseLong()
*/
public static long parseLong(byte[] b, int start, int end, int radix)
throws NumberFormatException {
if (b == null)
throw new NumberFormatException("null");

long result = 0;
boolean negative = false;
int i = start;
long limit;
long multmin;
int digit;
if (end > start) {
if (b[i] == "-") {
negative = true;
limit = Long.MIN_VALUE;
i++;
} else {
limit = -Long.MAX_VALUE;
}
multmin = limit / radix;
if (i < end) {
digit = Character.digit((char)b[i++], radix);
if (digit < 0) {
throw new NumberFormatException(
"illegal number: " + toString(b, start, end)
);
} else {
result = -digit;
}
}
while (i < end) {
// Accumulating negatively avoids surprises near MAX_VALUE
digit = Character.digit((char)b[i++], radix);
if (digit < 0) {
throw new NumberFormatException("illegal number");
}
if (result < multmin) {
throw new NumberFormatException("illegal number");
}
result *= radix;
if (result < limit + digit) {
throw new NumberFormatException("illegal number");
}
result -= digit;
}
} else {
throw new NumberFormatException("illegal number");
}
if (negative) {
if (i > start + 1) {
return result;
} else { /* Only got "-" */
throw new NumberFormatException("illegal number");
}
} else {
return -result;
}
}
/**
* Convert the bytes within the specified range of the given byte
* array into a signed long . The range extends from
* <code>start</code> till, but not including <code>end</code>. 
*/
public static long parseLong(byte[] b, int start, int end)
throws NumberFormatException {
return parseLong(b, start, end, 10);
}
/**
* Convert the bytes within the specified range of the given byte
* array into a String. The range extends from <code>start</code>
* till, but not including <code>end</code>. 
*/
public static String toString(byte[] b, int start, int end) {
int size = end - start;
char[] theChars = new char[size];
for (int i = 0, j = start; i < size; )
theChars[i++] = (char)(b[j++]&0xff);

return new String(theChars);
}
public static String toString(ByteArrayInputStream is) {
int size = is.available();
char[] theChars = new char[size];
byte[] bytes = new byte[size];
is.read(bytes, 0, size);
for (int i = 0; i < size;)
theChars[i] = (char)(bytes[i++]&0xff);

return new String(theChars);
}

public static byte[] getBytes(String s) {
char [] chars= s.toCharArray();
int size = chars.length;
byte[] bytes = new byte[size];

for (int i = 0; i < size;)
bytes[i] = (byte) chars[i++];
return bytes;
}
public static byte[] getBytes(InputStream is) throws IOException {
int len;
int size = 1024;
byte [] buf;

if (is instanceof ByteArrayInputStream) {
size = is.available();
buf = new byte[size];
len = is.read(buf, 0, size);
}
else {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
buf = new byte[size];
while ((len = is.read(buf, 0, size)) != -1)
bos.write(buf, 0, len);
buf = bos.toByteArray();
}
return buf;
}
}

</source>



== Display the ISO Latin-1 character set ==



<source lang="java">

public class LatinSet {
public static void main(String[] args) {
System.out.println("ISO LATIN-1 CHARACTER SET");
for (int x = 160; x < 255; x++) {
System.out.print((char) x);
System.out.print(" ");
if (x % 8 == 7)
System.out.print("\n");
}
}
}

</source>



== Reading CRLF terminated lines that contain only US-ASCII characters from an input stream ==



<source lang="java">

import java.io.*;
/**
* This class is to support reading CRLF terminated lines that
* contain only US-ASCII characters from an input stream. Provides
* functionality that is similar to the deprecated
* <code>DataInputStream.readLine()</code>. Expected use is to read
* lines as String objects from a RFC822 stream.
*
* It is implemented as a FilterInputStream, so one can just wrap
* this class around any input stream and read bytes from this filter.
*
* @author John Mani
*/
public class LineInputStream extends FilterInputStream {
private char[] lineBuffer = null; // reusable byte buffer
public LineInputStream(InputStream in) {
super(in);
}
/**
* Read a line containing only ASCII characters from the input
* stream. A line is terminated by a CR or NL or CR-NL sequence.
* A common error is a CR-CR-NL sequence, which will also terminate
* a line.
* The line terminator is not returned as part of the returned
* String. Returns null if no data is available. 
*
* This class is similar to the deprecated
* <code>DataInputStream.readLine()</code>
*/
public String readLine() throws IOException {
InputStream in = this.in;
char[] buf = lineBuffer;
if (buf == null)
buf = lineBuffer = new char[128];
int c1;
int room = buf.length;
int offset = 0;
while ((c1 = in.read()) != -1) {
if (c1 == "\n") // Got NL, outa here.
break;
else if (c1 == "\r") {
// Got CR, is the next char NL ?
int c2 = in.read();
if (c2 == "\r") // discard extraneous CR
c2 = in.read();
if (c2 != "\n") {
// If not NL, push it back
if (!(in instanceof PushbackInputStream))
in = this.in = new PushbackInputStream(in);
((PushbackInputStream)in).unread(c2);
}
break; // outa here.
}
// Not CR, NL or CR-NL ...
// .. Insert the byte into our byte buffer
if (--room < 0) { // No room, need to grow.
buf = new char[offset + 128];
room = buf.length - offset - 1;
System.arraycopy(lineBuffer, 0, buf, 0, offset);
lineBuffer = buf;
}
buf[offset++] = (char)c1;
}
if ((c1 == -1) && (offset == 0))
return null;

return String.copyValueOf(buf, 0, offset);
}
}

</source>

← Предыдущая	Версия 07:06, 1 июня 2010
(нет различий)

Java/Development Class/Ascii Code - История изменений

Admin: 1 версия

в 18:01, 31 мая 2010