jdk/src/java.base/share/classes/sun/misc/UUEncoder.java
changeset 25859 3317bb8137f4
parent 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/sun/misc/UUEncoder.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 1995, 2004, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package sun.misc;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.io.IOException;
+
+/**
+ * This class implements a Berkeley uu character encoder. This encoder
+ * was made famous by uuencode program.
+ *
+ * The basic character coding is algorithmic, taking 6 bits of binary
+ * data and adding it to an ASCII ' ' (space) character. This converts
+ * these six bits into a printable representation. Note that it depends
+ * on the ASCII character encoding standard for english. Groups of three
+ * bytes are converted into 4 characters by treating the three bytes
+ * a four 6 bit groups, group 1 is byte 1's most significant six bits,
+ * group 2 is byte 1's least significant two bits plus byte 2's four
+ * most significant bits. etc.
+ *
+ * In this encoding, the buffer prefix is:
+ * <pre>
+ *     begin [mode] [filename]
+ * </pre>
+ *
+ * This is followed by one or more lines of the form:
+ * <pre>
+ *      (len)(data)(data)(data) ...
+ * </pre>
+ * where (len) is the number of bytes on this line. Note that groupings
+ * are always four characters, even if length is not a multiple of three
+ * bytes. When less than three characters are encoded, the values of the
+ * last remaining bytes is undefined and should be ignored.
+ *
+ * The last line of data in a uuencoded file is represented by a single
+ * space character. This is translated by the decoding engine to a line
+ * length of zero. This is immediately followed by a line which contains
+ * the word 'end[newline]'
+ *
+ * @author      Chuck McManis
+ * @see         CharacterEncoder
+ * @see         UUDecoder
+ */
+public class UUEncoder extends CharacterEncoder {
+
+    /**
+     * This name is stored in the begin line.
+     */
+    private String bufferName;
+
+    /**
+     * Represents UNIX(tm) mode bits. Generally three octal digits representing
+     * read, write, and execute permission of the owner, group owner, and
+     * others. They should be interpreted as the bit groups:
+     * (owner) (group) (others)
+     *  rwx      rwx     rwx    (r = read, w = write, x = execute)
+     *
+     * By default these are set to 644 (UNIX rw-r--r-- permissions).
+     */
+    private int mode;
+
+
+    /**
+     * Default - buffer begin line will be:
+     * <pre>
+     *  begin 644 encoder.buf
+     * </pre>
+     */
+    public UUEncoder() {
+        bufferName = "encoder.buf";
+        mode = 644;
+    }
+
+    /**
+     * Specifies a name for the encoded buffer, begin line will be:
+     * <pre>
+     *  begin 644 [FNAME]
+     * </pre>
+     */
+    public UUEncoder(String fname) {
+        bufferName = fname;
+        mode = 644;
+    }
+
+    /**
+     * Specifies a name and mode for the encoded buffer, begin line will be:
+     * <pre>
+     *  begin [MODE] [FNAME]
+     * </pre>
+     */
+    public UUEncoder(String fname, int newMode) {
+        bufferName = fname;
+        mode = newMode;
+    }
+
+    /** number of bytes per atom in uuencoding is 3 */
+    protected int bytesPerAtom() {
+        return (3);
+    }
+
+    /** number of bytes per line in uuencoding is 45 */
+    protected int bytesPerLine() {
+        return (45);
+    }
+
+    /**
+     * encodeAtom - take three bytes and encodes them into 4 characters
+     * If len is less than 3 then remaining bytes are filled with '1'.
+     * This insures that the last line won't end in spaces and potentiallly
+     * be truncated.
+     */
+    protected void encodeAtom(OutputStream outStream, byte data[], int offset, int len)
+        throws IOException {
+        byte    a, b = 1, c = 1;
+        int     c1, c2, c3, c4;
+
+        a = data[offset];
+        if (len > 1) {
+            b = data[offset+1];
+        }
+        if (len > 2) {
+            c = data[offset+2];
+        }
+
+        c1 = (a >>> 2) & 0x3f;
+        c2 = ((a << 4) & 0x30) | ((b >>> 4) & 0xf);
+        c3 = ((b << 2) & 0x3c) | ((c >>> 6) & 0x3);
+        c4 = c & 0x3f;
+        outStream.write(c1 + ' ');
+        outStream.write(c2 + ' ');
+        outStream.write(c3 + ' ');
+        outStream.write(c4 + ' ');
+        return;
+    }
+
+    /**
+     * Encode the line prefix which consists of the single character. The
+     * lenght is added to the value of ' ' (32 decimal) and printed.
+     */
+    protected void encodeLinePrefix(OutputStream outStream, int length)
+        throws IOException {
+        outStream.write((length & 0x3f) + ' ');
+    }
+
+
+    /**
+     * The line suffix for uuencoded files is simply a new line.
+     */
+    protected void encodeLineSuffix(OutputStream outStream) throws IOException {
+        pStream.println();
+    }
+
+    /**
+     * encodeBufferPrefix writes the begin line to the output stream.
+     */
+    protected void encodeBufferPrefix(OutputStream a) throws IOException {
+        super.pStream = new PrintStream(a);
+        super.pStream.print("begin "+mode+" ");
+        if (bufferName != null) {
+            super.pStream.println(bufferName);
+        } else {
+            super.pStream.println("encoder.bin");
+        }
+        super.pStream.flush();
+    }
+
+    /**
+     * encodeBufferSuffix writes the single line containing space (' ') and
+     * the line containing the word 'end' to the output stream.
+     */
+    protected void encodeBufferSuffix(OutputStream a) throws IOException {
+        super.pStream.println(" \nend");
+        super.pStream.flush();
+    }
+
+}