Java实现MD5, SHA-1, BASE64, 3DES加解密方法

import java.security.MessageDigest;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

/**
* Java 加解密工具类
*
* @author mosesxin@gmail.com
*
*/
public class EncryptUtil {

private static final String UTF8 = "utf-8";
//定义 加密算法,可用 DES,DESede,Blowfish
private static final String ALGORITHM_DESEDE = "DESede";

/**
* MD5数字签名
*
* @param src
* @return
* @throws Exception
*/
public String md5Digest(String src) throws Exception {
// 定义数字签名方法, 可用：MD5, SHA-1
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] b = md.digest(src.getBytes(UTF8));

return this.byte2HexStr(b);
}

/**
* BASE64 加密
*
* @param src
* @return
* @throws Exception
*/
public String base64Encoder(String src) throws Exception {
BASE64Encoder encoder = new BASE64Encoder();
return encoder.encode(src.getBytes(UTF8));
}

/**
* BASE64解密
*
* @param dest
* @return
* @throws Exception
*/
public String base64Decoder(String dest) throws Exception {
BASE64Decoder decoder = new BASE64Decoder();
return new String(decoder.decodeBuffer(dest), UTF8);
}

/**
* 3DES加密
*
* @param src
* @param key
* @return
* @throws Exception
*/
public String desedeEncoder(String src, String key) throws Exception {
SecretKey secretKey = new SecretKeySpec(build3DesKey(key), ALGORITHM_DESEDE);
Cipher cipher = Cipher.getInstance(ALGORITHM_DESEDE);
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
byte[] b = cipher.doFinal(src.getBytes(UTF8));

return byte2HexStr(b);
}

/**
* 3DES解密
*
* @param dest
* @param key
* @return
* @throws Exception
*/
public String desedeDecoder(String dest, String key) throws Exception {
SecretKey secretKey = new SecretKeySpec(build3DesKey(key), ALGORITHM_DESEDE);
Cipher cipher = Cipher.getInstance(ALGORITHM_DESEDE);
cipher.init(Cipher.DECRYPT_MODE, secretKey);
byte[] b = cipher.doFinal(str2ByteArray(dest));

return new String(b, UTF8);

}

/**
* 字节数组转化为大写16进制字符串
*
* @param b
* @return
*/
private String byte2HexStr(byte[] b) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < b.length; i++) {
String s = Integer.toHexString(b[i] & 0xFF);
if (s.length() == 1) {
sb.append("0");
}

sb.append(s.toUpperCase());
}

return sb.toString();
}

/**
* 字符串转字节数组
*
* @param s
* @return
*/
private byte[] str2ByteArray(String s) {
int byteArrayLength = s.length()/2;
byte[] b = new byte[byteArrayLength];
for (int i = 0; i < byteArrayLength; i++) {
byte b0 = (byte) Integer.valueOf(s.substring(i*2, i*2+2), 16).intValue();
b[i] = b0;
}

return b;
}

/**
* 构造3DES加解密方法key
*
* @param keyStr
* @return
* @throws Exception
*/
private byte[] build3DesKey(String keyStr) throws Exception {
byte[] key = new byte[24];
byte[] temp = keyStr.getBytes(UTF8);
if (key.length > temp.length) {
System.arraycopy(temp, 0, key, 0, temp.length);
} else {
System.arraycopy(temp, 0, key, 0, key.length);
}

return key;
}
}