java数据加密算法

需要commons-codec-1.7.jar包，下载地址：http://commons.apache.org/codec/download_codec.cgi

直接看我改过的代码（栗子里还要转换成byte数组再转换回来太麻烦，我重新封装了栗子里操作BASE64的方法，用的时候直接传进去需要加密的String，它就返回加完密的字符串，方便使用。需要加密的同学直接拿下面代码用就好。不过BASE64好像可以直接传String参数，反正都一样 无所谓了）：

 import org.apache.commons.codec.binary.Base64;
 
 public class MyEncrypt {
 
     // sun不推荐使用它们自己的base64,用apache的挺好
     /**
      * BASE64解密
      */
     public static String decryptBASE64(String dest) {
         if (dest == null) {
             return null;
         }
         byte[] d = dest.getBytes();
         String s = new String(Base64.decodeBase64(d));
         return s;
     }
 
     /**
      * BASE64加密
      */
     public static String encryptBASE64(String origin) {
         if (origin == null) {
             return null;
         }
         byte [] d = origin.getBytes();
         String s = new String(Base64.encodeBase64(d));
         return s;
     }
     public static void main(String[] args) throws Exception {
         // TODO Auto-generated method stub
         String d = "Akishimo";
         String ed = encryptBASE64(d);
         String edd = decryptBASE64(ed);
         System.out.println("我的密码为："+d);
         System.out.println("加密后为;"+ ed);
         System.out.println("再解密之后:"+edd);
     }
 }

这个是网上找的栗子：

package com.qfnu.officeoa.util.encrypt;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;

public class MyEncrypt {
    public static final String KEY_SHA = "SHA";
    public static final String KEY_MD5 = "MD5";
    public static final String KEY_MAC = "HmacMD5";

    // sun不推荐使用它们自己的base64,用apache的挺好
    /**
     * BASE64解密
     */
    public static byte[] decryptBASE64(byte[] dest) {
        if (dest == null) {
            return null;
        }
        return Base64.decodeBase64(dest);
    }

    /**
     * BASE64加密
     */
    public static byte[] encryptBASE64(byte[] origin) {
        if (origin == null) {
            return null;
        }
        return Base64.encodeBase64(origin);
    }

    /**
     * MD5加密
     * 
     * @throws NoSuchAlgorithmException
     */
    public static byte[] encryptMD5(byte[] data)
            throws NoSuchAlgorithmException {
        if (data == null) {
            return null;
        }
        MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);
        md5.update(data);
        return md5.digest();
    }

    /**
     * SHA加密
     * 
     * @throws NoSuchAlgorithmException
     */
    public static byte[] encryptSHA(byte[] data)
            throws NoSuchAlgorithmException {
        if (data == null) {
            return null;
        }
        MessageDigest sha = MessageDigest.getInstance(KEY_SHA);
        sha.update(data);
        return sha.digest();
    }

    /**
     * 初始化HMAC密钥
     * 
     * @throws NoSuchAlgorithmException
     */
    public static String initMacKey() throws NoSuchAlgorithmException {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);
        SecretKey secretKey = keyGenerator.generateKey();
        return new String(encryptBASE64(secretKey.getEncoded()));
    }

    /**
     * HMAC加密
     * 
     * @throws NoSuchAlgorithmException
     * @throws InvalidKeyException
     */
    public static byte[] encryptHMAC(byte[] data, String key)
            throws NoSuchAlgorithmException, InvalidKeyException {
        SecretKey secretKey = new SecretKeySpec(decryptBASE64(key.getBytes()),
                KEY_MAC);
        Mac mac = Mac.getInstance(secretKey.getAlgorithm());
        mac.init(secretKey);
        return mac.doFinal(data);

    }

    public static void main(String[] args) throws Exception {
        // 例子里给的那一大长串传参调用太头疼，我简化一下写出来了，d加密之前的字符，ed代表加密之后，edd代表解密之后，大家直接拿来用就行。   
　　　　  String d = "Akishimo";
        String ed = new String(encryptBASE64(d.getBytes()));
        String edd = new String(decryptBASE64(ed.getBytes()));
        System.out.println("我的密码为："+d);
        System.out.println("加密后为;"+ ed);
        System.out.println("再解密之后"+edd);
        System.out.println("****************************************************************");
        String data = "简单加密";
        String a =new BigInteger(encryptBASE64(data.getBytes()))
        .toString(32);
        System.out.println(new BigInteger(encryptBASE64(data.getBytes())).toString(16));
        System.out.println(a);
        System.out.println("haha"+new String(decryptBASE64(encryptBASE64(data.getBytes()))));
        System.out.println(new BigInteger(encryptMD5(data.getBytes()))
                .toString());
        System.out.println(new BigInteger(encryptSHA(data.getBytes()))
                .toString());
        System.out.println(new BigInteger(encryptHMAC(data.getBytes(),
                initMacKey())).toString());
    }
}

这里面有好几种加密方法，我觉得BASE64好用就只用了这种，其他的使用方法例子里也有，大家自己拿来用就行。原文地址http://justsee.iteye.com/blog/747824