java 简单的加解密操作

import java.io.ByteArrayOutputStream;

/**
* @see 这是一个加解密的工具类
* 加密中包含中文时,先进行其他编码,URLEncoder.encode(str) 然后在进行加密操作
* 解密完成后再使用URLDecoder.decode 解码
* @version 1.0.0
* @since 2016-3-14 15:39:33
* @author zuoxin.xiao email:xiao574182979@126.com
*/
public final class EncryptUtil {

public 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', '+', '/','=','%' };

public 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, 65, -1,
-1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,
60, 61, -1, -1, -1, 64, -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 };
/**
* @see  加密中包含中文时,先进行其他编码,URLEncoder.encode(str) 然后在进行加密操作
* @param value
* @return
*/
public static String encode(String value){
String output = "";
char chr1,chr2 = 0,chr3=0 ;
int enc1, enc2, enc3, enc4;
int i = 0;

do{
char[] values = value.toCharArray();
chr1 = values[i++];
boolean isChr2Error = false;
boolean isChr3Error = false;
try {
chr2 = values[i++];
} catch (Exception e) {
isChr2Error = true;
}

try {
chr3 = values[i++];
} catch (Exception e) {
isChr3Error = true;
}

enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;

if(isChr2Error){
enc3 = enc4 = 64;
} else if(isChr3Error){
enc4 = 64;
}

output = output + base64EncodeChars[enc1] + base64EncodeChars[enc2]
+ base64EncodeChars[enc3] + base64EncodeChars[enc4];

}while( i < value.length());

return output;
}

/**
* @see 解密 若包含中文时完成后再使用URLDecoder.decode 解码
*
* @param str
* @return
*/
public static byte[] decode(String str) {
byte[] data = str.getBytes();
int len = data.length;
ByteArrayOutputStream buf = new ByteArrayOutputStream(len);
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;
}
buf.write((int) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

do {
b3 = data[i++];
if (b3 == 61) {
return buf.toByteArray();
}
b3 = base64DecodeChars[b3];
} while (i < len && b3 == -1);
if (b3 == -1) {
break;
}
buf.write((int) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

do {
b4 = data[i++];
if (b4 == 61) {
return buf.toByteArray();
}
b4 = base64DecodeChars[b4];
} while (i < len && b4 == -1);
if (b4 == -1) {
break;
}

buf.write( (((b3 & 0x03) << 6) | b4));
}
return buf.toByteArray();
}
}