java安全架构____Hmac秘钥加密自己的摘要数据

import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

/**
 * @author Administrator HMAC util
 */
public class HmacUtil {
	private static final String ALGORITHM_HMACMD5="HmacMD5";
	/**
	 * nothing about algorithm :HmacMD5,AES(128),DESede(168),HmacSHA1,HmacSHA256
	 * SecureRandom : use default config random user nextint
	 * encode : (byte to base64bytes)to String
	 * @return
	 */
	public static String init() {
		String key = "";
		try {
			KeyGenerator generator = KeyGenerator.getInstance(ALGORITHM_HMACMD5);
			SecretKey secretKey=generator.generateKey();
			byte[]bytes=encode(secretKey.getEncoded());
			key=new String(bytes);
			System.out.println(key);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return key;
	}
	
	 /**  
     * USE HmacMD5 
     * @param plainText 
     * @param key  
     * @return  
     */    
    public static String HmacEncrypt(String plainText, String key) {           
		Mac mac = null;
		try {
			SecretKey secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM_HMACMD5);
			mac = Mac.getInstance(ALGORITHM_HMACMD5);
			mac.init(secretKey);
		} catch (Exception e) {
			e.printStackTrace();
		}
 		byte[] dataBytes =mac.doFinal(plainText.getBytes());
 		return new String(encode(dataBytes)); 
    }    
	
	/**
	 * base64 encode
	 * @param plainBytes
	 * @return  byte[]
	 */
	public static byte[] encode(byte[]plainBytes){
		Base64 base64=new Base64();
		return base64.encode(plainBytes);
	}
	/**
	 * base64 decode
	 * @param cipherText
	 * @return byte[]
	 */
	public static byte[] decode(byte[]cipherText){
		Base64 base64=new Base64();
		return base64.decode(cipherText);
	}     
	
	public static void main(String[] args) {
		String str="我是张三";
		System.out.println("明文信息:"+str);
		String key = init();
		System.out.println("生成的秘钥为__:"+key);
		String hmacKey=HmacEncrypt(str, key);
		System.out.println("用自己的秘钥做信息摘要__:"+hmacKey);
	}

//===================运行结果

明文信息:我是张三
MF8mW4etH60UzW8xELiCmMGN3gdgO+fFyW0Pivg8pD+pd8cB8Y2BYGSrCfOQAXvHbDMFkK1xfytkYERMq3bQYA==
生成的秘钥为__:MF8mW4etH60UzW8xELiCmMGN3gdgO+fFyW0Pivg8pD+pd8cB8Y2BYGSrCfOQAXvHbDMFkK1xfytkYERMq3bQYA==
用自己的秘钥做信息摘要__:REsuoeYttq8fSVfTe+iD4A==