• Java Base64Utils


    Java Base64Utils

    /**
     * <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, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
    			60, 61, -1, -1, -1, -1, -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 };
    
    	/**
    	 * 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) {
    		
    	}
    }
    

      

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  • 原文地址:https://www.cnblogs.com/jasonandy/p/9243310.html
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