Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
com.aliyuncs.utils.Base64Helper 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 com.aliyuncs.utils;
import java.io.UnsupportedEncodingException;
public class Base64Helper {
private static final String BASE64_CODE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz" + "0123456789" + "+/";
private static final int[] BASE64_DECODE = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
private static byte[] zeroPad(int length, byte[] bytes) {
byte[] padded = new byte[length];
System.arraycopy(bytes, 0, padded, 0, bytes.length);
return padded;
}
public synchronized static String encode(byte[] buff) {
if (null == buff)
return null;
StringBuilder strBuilder = new StringBuilder("");
int paddingCount = (3 - (buff.length % 3)) % 3;
byte[] stringArray = zeroPad(buff.length + paddingCount, buff);
for (int i = 0; i < stringArray.length; i += 3) {
int j = ((stringArray[i] & 0xff) << 16) +
((stringArray[i + 1] & 0xff) << 8) +
(stringArray[i + 2] & 0xff);
strBuilder.append(BASE64_CODE.charAt((j >> 18) & 0x3f));
strBuilder.append(BASE64_CODE.charAt((j >> 12) & 0x3f));
strBuilder.append(BASE64_CODE.charAt((j >> 6) & 0x3f));
strBuilder.append(BASE64_CODE.charAt(j & 0x3f));
}
int intPos = strBuilder.length();
for (int i = paddingCount; i > 0; i --) {
strBuilder.setCharAt(intPos - i, '=');
}
return strBuilder.toString();
}
public synchronized static String encode(String string, String encoding)
throws UnsupportedEncodingException {
if (null == string || null == encoding)
return null;
byte[] stringArray = string.getBytes(encoding);
return encode(stringArray);
}
public synchronized static String decode(String string, String encoding) throws
UnsupportedEncodingException{
if (null == string || null == encoding)
return null;
int posIndex = 0;
int decodeLen = string.endsWith( "==" ) ? (string.length() - 2) :
string.endsWith( "=" ) ? (string.length() - 1) : string.length();
byte[] buff = new byte[decodeLen *3 / 4];
int count4 = decodeLen - decodeLen %4;
for(int i = 0; i< count4; i += 4){
int c0 = BASE64_DECODE[string.charAt( i )];
int c1 = BASE64_DECODE[string.charAt( i + 1)];
int c2 = BASE64_DECODE[string.charAt( i + 2)];
int c3 = BASE64_DECODE[string.charAt( i + 3)];
buff[posIndex ++ ] = (byte)(((c0 << 2) | (c1 >> 4)) & 0xFF);
buff[posIndex ++ ] = (byte)((((c1 & 0xF) << 4) | (c2 >> 2)) & 0xFF);
buff[posIndex ++ ] = (byte)((((c2 & 3) << 6) | c3) & 0xFF);
}
if (2 <= decodeLen%4) {
int c0 = BASE64_DECODE[string.charAt(count4)];
int c1 = BASE64_DECODE[string.charAt(count4 + 1)];
buff[posIndex ++ ] = (byte)(((c0 << 2) | (c1 >> 4)) & 0xFF);
if (3 == decodeLen%4) {
int c2 = BASE64_DECODE[string.charAt( count4 + 2)];
buff[posIndex ++ ] = (byte)((((c1 & 0xF) << 4) | (c2 >> 2)) & 0xFF);
}
}
return new String(buff, encoding);
}
}
