Java Base64Utils ----Utils

Java Base64Utils

 

Java Base64Utils

7
/**
 * <html>
 * <body>
 *  <P> Copyright 1994 JsonInternational</p>
 *  <p> All rights reserved.</p>
 *  <p> Created on 19941115</p>
 *  <p> Created by Jason</p>
 *  </body>
 * </html>
 */
package cn.ucaner.alpaca.framework.utils.encrypt;
 
/**
* @Package:cn.ucaner.common.utils.encrypt  
* @ClassName:Base64Utils  
* @Description:   <p> BASE64加解密工具类</p>
* @Author: - Jason
* @CreatTime:2017年10月25日 下午5:49:33  
* @Modify By:  
* @ModifyTime: 
* @Modify marker:  
* @version    V1.0
 */
class Base64Utils {
 
    private static char[] base64EncodeChars = new char[] { 'A''B''C''D',
            'E''F''G''H''I''J''K''L''M''N''O''P''Q',
            'R''S''T''U''V''W''X''Y''Z''a''b''c''d',
            'e''f''g''h''i''j''k''l''m''n''o''p''q',
            'r''s''t''u''v''w''x''y''z''0''1''2''3',
            '4''5''6''7''8''9''+''/' };
 
    private static byte[] base64DecodeChars = new byte[] { -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, -162, -1, -1, -1635253545556575859,
            6061, -1, -1, -1, -1, -1, -1, -10123456789,
            10111213141516171819202122232425, -1,
            -1, -1, -1, -1, -1262728293031323334353637,
            3839404142434445464748495051, -1, -1, -1,
            -1, -1 };
 
    /**
     * BASE64加密
     * @param data
     * @return
     */
    protected static String encrypt(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;
        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                        | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4)
                    | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2)
                    | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }
 
    /**
     * Base64 解密
     * @param str
     * @return
     * @throws Exception
     */
    protected static byte[] decrypt(String str) throws Exception{
        StringBuffer sb = new StringBuffer();
        byte[] data =  str.getBytes("US-ASCII");
        int len = data.length;
        int i = 0;
        int b1, b2, b3, b4;
        while (i < len) {
 
            do {
                b1 = base64DecodeChars[data[i++]];
            while (i < len && b1 == -1);
            if (b1 == -1)
                break;
 
            do {
                b2 = base64DecodeChars[data[i++]];
            while (i < len && b2 == -1);
            if (b2 == -1)
                break;
            sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4)));
 
            do {
                b3 = data[i++];
                if (b3 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b3 = base64DecodeChars[b3];
            while (i < len && b3 == -1);
            if (b3 == -1)
                break;
            sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));
 
            do {
                b4 = data[i++];
                if (b4 == 61)
                    return sb.toString().getBytes("iso8859-1");
                b4 = base64DecodeChars[b4];
            while (i < len && b4 == -1);
            if (b4 == -1)
                break;
            sb.append((char) (((b3 & 0x03) << 6) | b4));
        }
        return sb.toString().getBytes("iso8859-1");
    }
     
     /**
     *For Test By Jason
     */
    public static void main(String[] args) {
         
    }
}

  

 

分类: JavaUtils
标签: java工具
posted @ 2019-11-22 13:44  kelelipeng  阅读(374)  评论(0编辑  收藏  举报