MD5加密解密帮助类带测试

package com.cloudsoar3c.tools;

import java.io.UnsupportedEncodingException;

import java.security.InvalidKeyException;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

import java.security.SecureRandom;

import java.util.Date;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import javax.crypto.KeyGenerator;

import javax.crypto.NoSuchPaddingException;

import javax.crypto.SecretKey;

import javax.crypto.spec.SecretKeySpec;

public class Encrypt {
/**
* 加密
* @param content 需要加密的内容
* @param password 加密密码
* @return 加密后的byte[]
*/
public static byte[] encrypt(String content) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(Attribute.AES_ENCRYPT_PASSWORD.getBytes());
kgen.init(128,sr);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
byte[] byteContent = content.getBytes("utf-8");
//byte[] byteContent = content.getBytes("gbk");
cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(byteContent);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}

/**
* 解密
* @param content待解密内容
* @param password解密密钥
* @return 
*/
public static byte[] decrypt(byte[] content) {
try {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
//SecureRandom sr = new SecureRandom(Attribute.AES_ENCRYPT_PASSWORD.getBytes());
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(Attribute.AES_ENCRYPT_PASSWORD.getBytes());
kgen.init(128, sr);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");// 创建密码器
cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
byte[] result = cipher.doFinal(content);
return result; // 加密
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}

    /**将二进制转换成16进制

     * @param buf

     * @return

     */

    public static String parseByte2HexStr(byte buf[]) {

            StringBuffer sb = new StringBuffer();

            for (int i = 0; i < buf.length; i++) {

                    String hex = Integer.toHexString(buf[i] & 0xFF);

                    if (hex.length() == 1) {

                            hex = '0' + hex;

                    }

                    sb.append(hex.toUpperCase());

            }

            return sb.toString();

    }

    

    /**将16进制转换为二进制

     * @param hexStr

     * @return

     */

    public static byte[] parseHexStr2Byte(String hexStr) {

            if (hexStr.length() < 1)

                    return null;

            byte[] result = new byte[hexStr.length()/2];

            for (int i = 0;i< hexStr.length()/2; i++) {

                    int high = Integer.parseInt(hexStr.substring(i*2, i*2+1), 16);

                    int low = Integer.parseInt(hexStr.substring(i*2+1, i*2+2), 16);

                    result[i] = (byte) (high * 16 + low);

            }

            return result;

    }

    /**

     * MD5加密

     * @param str

     * @param isSrue

     * @return

     */

    public static String md5Encrypt(String str, boolean isSrue) {
if (isSrue) {
MessageDigest messageDigest = null;
try {
messageDigest = MessageDigest.getInstance("MD5");
messageDigest.reset();
messageDigest.update(str.getBytes("UTF-8"));
} catch (NoSuchAlgorithmException e) {
System.out.println("NoSuchAlgorithmException caught!");
System.exit(-1);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
byte[] byteArray = messageDigest.digest();
StringBuffer md5StrBuff = new StringBuffer();
for (int i = 0; i < byteArray.length; i++) {
if (Integer.toHexString(0xFF & byteArray[i]).length() == 1) {
md5StrBuff.append("0").append(
Integer.toHexString(0xFF & byteArray[i]));
} else {
md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));
}
}
return md5StrBuff.toString();
}
return "";
}

    
public static void main(String[] args) {

        String content = "1234";

        //加密

        System.out.println("加密前：" + content);

        byte[] encryptResult = encrypt(content);

        String encryptResultStr = parseByte2HexStr(encryptResult);
//String encryptResultStr = "EFC667D888D058D817C602FD68DD33FC";

        System.out.println("加密后：" + encryptResultStr);

        //解密

        byte[] decryptFrom = parseHexStr2Byte(encryptResultStr);

        byte[] decryptResult = decrypt(decryptFrom);

        System.out.println("解密后：##" + new String(decryptResult)+"##");

        System.out.println(Attribute.SDF_YMD_ID.format(new Date()));
}

}