org.jvnet.staxex.Base64Encoder Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package org.jvnet.staxex;
/**
* @author Kohsuke Kawaguchi
*/
class Base64Encoder {
private static final char[] encodeMap = initEncodeMap();
private static char[] initEncodeMap() {
char[] map = new char[64];
int i;
for( i= 0; i<26; i++ ) map[i] = (char)('A'+i);
for( i=26; i<52; i++ ) map[i] = (char)('a'+(i-26));
for( i=52; i<62; i++ ) map[i] = (char)('0'+(i-52));
map[62] = '+';
map[63] = '/';
return map;
}
public static char encode( int i ) {
return encodeMap[i&0x3F];
}
public static byte encodeByte( int i ) {
return (byte)encodeMap[i&0x3F];
}
public static String print(byte[] input, int offset, int len) {
char[] buf = new char[((len+2)/3)*4];
int ptr = print(input,offset,len,buf,0);
assert ptr==buf.length;
return new String(buf);
}
/**
* Encodes a byte array into a char array by doing base64 encoding.
*
* The caller must supply a big enough buffer.
*
* @return
* the value of {@code ptr+((len+2)/3)*4}, which is the new offset
* in the output buffer where the further bytes should be placed.
*/
public static int print(byte[] input, int offset, int len, char[] buf, int ptr) {
for( int i=offset; i>2);
buf[ptr++] = encode(((input[i])&0x3)<<4);
buf[ptr++] = '=';
buf[ptr++] = '=';
break;
case 2:
buf[ptr++] = encode(input[i]>>2);
buf[ptr++] = encode(
((input[i]&0x3)<<4) |
((input[i+1]>>4)&0xF));
buf[ptr++] = encode((input[i+1]&0xF)<<2);
buf[ptr++] = '=';
break;
default:
buf[ptr++] = encode(input[i]>>2);
buf[ptr++] = encode(
((input[i]&0x3)<<4) |
((input[i+1]>>4)&0xF));
buf[ptr++] = encode(
((input[i+1]&0xF)<<2)|
((input[i+2]>>6)&0x3));
buf[ptr++] = encode(input[i+2]&0x3F);
break;
}
}
return ptr;
}
}