ohair@286: /*
ohair@286:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package com.sun.xml.internal.org.jvnet.staxex;
ohair@286: 
ohair@286: /**
ohair@286:  * @author Kohsuke Kawaguchi
ohair@286:  */
ohair@286: class Base64Encoder {
ohair@286:     private static final char[] encodeMap = initEncodeMap();
ohair@286: 
ohair@286:     private static char[] initEncodeMap() {
ohair@286:         char[] map = new char[64];
ohair@286:         int i;
ohair@286:         for( i= 0; i<26; i++ )        map[i] = (char)('A'+i);
ohair@286:         for( i=26; i<52; i++ )        map[i] = (char)('a'+(i-26));
ohair@286:         for( i=52; i<62; i++ )        map[i] = (char)('0'+(i-52));
ohair@286:         map[62] = '+';
ohair@286:         map[63] = '/';
ohair@286: 
ohair@286:         return map;
ohair@286:     }
ohair@286: 
ohair@286:     public static char encode( int i ) {
ohair@286:         return encodeMap[i&0x3F];
ohair@286:     }
ohair@286: 
ohair@286:     public static byte encodeByte( int i ) {
ohair@286:         return (byte)encodeMap[i&0x3F];
ohair@286:     }
ohair@286: 
ohair@286:     public static String print(byte[] input, int offset, int len) {
ohair@286:         char[] buf = new char[((len+2)/3)*4];
ohair@286:         int ptr = print(input,offset,len,buf,0);
ohair@286:         assert ptr==buf.length;
ohair@286:         return new String(buf);
ohair@286:     }
ohair@286: 
ohair@286:     /**
ohair@286:      * Encodes a byte array into a char array by doing base64 encoding.
ohair@286:      *
ohair@286:      * The caller must supply a big enough buffer.
ohair@286:      *
ohair@286:      * @return
ohair@286:      *      the value of {@code ptr+((len+2)/3)*4}, which is the new offset
ohair@286:      *      in the output buffer where the further bytes should be placed.
ohair@286:      */
ohair@286:     public static int print(byte[] input, int offset, int len, char[] buf, int ptr) {
ohair@286:         for( int i=offset; i<len; i+=3 ) {
ohair@286:             switch( len-i ) {
ohair@286:             case 1:
ohair@286:                 buf[ptr++] = encode(input[i]>>2);
ohair@286:                 buf[ptr++] = encode(((input[i])&0x3)<<4);
ohair@286:                 buf[ptr++] = '=';
ohair@286:                 buf[ptr++] = '=';
ohair@286:                 break;
ohair@286:             case 2:
ohair@286:                 buf[ptr++] = encode(input[i]>>2);
ohair@286:                 buf[ptr++] = encode(
ohair@286:                             ((input[i]&0x3)<<4) |
ohair@286:                             ((input[i+1]>>4)&0xF));
ohair@286:                 buf[ptr++] = encode((input[i+1]&0xF)<<2);
ohair@286:                 buf[ptr++] = '=';
ohair@286:                 break;
ohair@286:             default:
ohair@286:                 buf[ptr++] = encode(input[i]>>2);
ohair@286:                 buf[ptr++] = encode(
ohair@286:                             ((input[i]&0x3)<<4) |
ohair@286:                             ((input[i+1]>>4)&0xF));
ohair@286:                 buf[ptr++] = encode(
ohair@286:                             ((input[i+1]&0xF)<<2)|
ohair@286:                             ((input[i+2]>>6)&0x3));
ohair@286:                 buf[ptr++] = encode(input[i+2]&0x3F);
ohair@286:                 break;
ohair@286:             }
ohair@286:         }
ohair@286:         return ptr;
ohair@286:     }
ohair@286: }