Dumps data in hexadecimal format
/*
* 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.
*/
import java.io.IOException;
import java.io.OutputStream;
/**
* Dumps data in hexadecimal format.
* <p>
* Provides a single function to take an array of bytes and display it
* in hexadecimal form.
* <p>
* Origin of code: POI.
*
* @author Scott Sanders
* @author Marc Johnson
* @version $Id: HexDump.java 596667 2007-11-20 13:50:14Z niallp $
*/
public class HexDump {
/**
* Instances should NOT be constructed in standard programming.
*/
public HexDump() {
super();
}
/**
* Dump an array of bytes to an OutputStream.
*
* @param data the byte array to be dumped
* @param offset its offset, whatever that might mean
* @param stream the OutputStream to which the data is to be
* written
* @param index initial index into the byte array
*
* @throws IOException is thrown if anything goes wrong writing
* the data to stream
* @throws ArrayIndexOutOfBoundsException if the index is
* outside the data array's bounds
* @throws IllegalArgumentException if the output stream is null
*/
public static void dump(byte[] data, long offset,
OutputStream stream, int index)
throws IOException, ArrayIndexOutOfBoundsException,
IllegalArgumentException {
if ((index < 0) || (index >= data.length)) {
throw new ArrayIndexOutOfBoundsException(
"illegal index: " + index + " into array of length "
+ data.length);
}
if (stream == null) {
throw new IllegalArgumentException("cannot write to nullstream");
}
long display_offset = offset + index;
StringBuffer buffer = new StringBuffer(74);
for (int j = index; j < data.length; j += 16) {
int chars_read = data.length - j;
if (chars_read > 16) {
chars_read = 16;
}
dump(buffer, display_offset).append(' ');
for (int k = 0; k < 16; k++) {
if (k < chars_read) {
dump(buffer, data[k + j]);
} else {
buffer.append(" ");
}
buffer.append(' ');
}
for (int k = 0; k < chars_read; k++) {
if ((data[k + j] >= ' ') && (data[k + j] < 127)) {
buffer.append((char) data[k + j]);
} else {
buffer.append('.');
}
}
buffer.append(EOL);
stream.write(buffer.toString().getBytes());
stream.flush();
buffer.setLength(0);
display_offset += chars_read;
}
}
/**
* The line-separator (initializes to "line.separator" system property.
*/
public static final String EOL =
System.getProperty("line.separator");
private static final char[] _hexcodes =
{
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F'
};
private static final int[] _shifts =
{
28, 24, 20, 16, 12, 8, 4, 0
};
/**
* Dump a long value into a StringBuffer.
*
* @param _lbuffer the StringBuffer to dump the value in
* @param value the long value to be dumped
* @return StringBuffer containing the dumped value.
*/
private static StringBuffer dump(StringBuffer _lbuffer, long value) {
for (int j = 0; j < 8; j++) {
_lbuffer
.append(_hexcodes[((int) (value >> _shifts[j])) & 15]);
}
return _lbuffer;
}
/**
* Dump a byte value into a StringBuffer.
*
* @param _cbuffer the StringBuffer to dump the value in
* @param value the byte value to be dumped
* @return StringBuffer containing the dumped value.
*/
private static StringBuffer dump(StringBuffer _cbuffer, byte value) {
for (int j = 0; j < 2; j++) {
_cbuffer.append(_hexcodes[(value >> _shifts[j + 6]) & 15]);
}
return _cbuffer;
}
}
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