org.apache.tools.ant.util.UUEncoder Maven / Gradle / Ivy
/*
* 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.
*
*/
package org.apache.tools.ant.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
/**
* UUEncoding of an input stream placed into an outputstream.
* This class is meant to be a drop in replacement for
* sun.misc.UUEncoder, which was previously used by Ant.
* The uuencode algorithm code has been copied from the
* geronimo project.
**/
public class UUEncoder {
protected static final int DEFAULT_MODE = 644;
private static final int MAX_CHARS_PER_LINE = 45;
private static final int INPUT_BUFFER_SIZE = MAX_CHARS_PER_LINE * 100;
private OutputStream out;
private String name;
/**
* Constructor specifying a name for the encoded buffer, begin
* line will be:
*
* begin 644 [NAME]
*
* @param name the name of the encoded buffer.
*/
public UUEncoder(String name) {
this.name = name;
}
/**
* UUEncode bytes from the input stream, and write them as text characters
* to the output stream. This method will run until it exhausts the
* input stream.
* @param is the input stream.
* @param out the output stream.
* @throws IOException if there is an error.
*/
public void encode(InputStream is, OutputStream out)
throws IOException {
this.out = out;
encodeBegin();
byte[] buffer = new byte[INPUT_BUFFER_SIZE];
int count;
while ((count = is.read(buffer, 0, buffer.length)) != -1) {
int pos = 0;
while (count > 0) {
int num = count > MAX_CHARS_PER_LINE
? MAX_CHARS_PER_LINE
: count;
encodeLine(buffer, pos, num, out);
pos += num;
count -= num;
}
}
out.flush();
encodeEnd();
}
/**
* Encode a string to the output.
*/
private void encodeString(String n) {
PrintStream writer = new PrintStream(out);
writer.print(n);
writer.flush();
}
private void encodeBegin() throws IOException {
encodeString("begin " + DEFAULT_MODE + " " + name + "\n");
}
private void encodeEnd() throws IOException {
encodeString(" \nend\n");
}
/**
* Encode a single line of data (less than or equal to 45 characters).
*
* @param data The array of byte data.
* @param off The starting offset within the data.
* @param length Length of the data to encode.
* @param out The output stream the encoded data is written to.
*
* @exception IOException
*/
private void encodeLine(
byte[] data, int offset, int length, OutputStream out)
throws IOException {
// write out the number of characters encoded in this line.
// CheckStyle:MagicNumber OFF
out.write((byte) ((length & 0x3F) + ' '));
// CheckStyle:MagicNumber ON
byte a;
byte b;
byte c;
for (int i = 0; i < length;) {
// set the padding defaults
b = 1;
c = 1;
// get the next 3 bytes (if we have them)
a = data[offset + i++];
if (i < length) {
b = data[offset + i++];
if (i < length) {
c = data[offset + i++];
}
}
// CheckStyle:MagicNumber OFF
byte d1 = (byte) (((a >>> 2) & 0x3F) + ' ');
byte d2 = (byte) ((((a << 4) & 0x30) | ((b >>> 4) & 0x0F)) + ' ');
byte d3 = (byte) ((((b << 2) & 0x3C) | ((c >>> 6) & 0x3)) + ' ');
byte d4 = (byte) ((c & 0x3F) + ' ');
// CheckStyle:MagicNumber ON
out.write(d1);
out.write(d2);
out.write(d3);
out.write(d4);
}
// terminate with a linefeed alone
out.write('\n');
}
}