DES加密和解密

DES加密和解密工具类：

package com.demo.Utils;

import java.security.Key;
import java.security.SecureRandom;
 
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
 
/**
 * DES是一种对称加密算法，所谓对称加密算法:加密和解密使用相同的秘钥的算法
 * 
 *
 */
public class DESUtil {
	private static final Logger logger = LoggerFactory.getLogger(DESUtil.class);
 
	private static Key key;
	//设置秘钥key
	private static String KEY_STR="myKey";
	private static String CHARSETNAME="UTF-8";
	private static String ALGORITHM="DES";
	
	static{
		try{
			//生成DES算法对象
			KeyGenerator generator=KeyGenerator.getInstance(ALGORITHM);
			//运用SHA1安全策略
			SecureRandom secureRandom=SecureRandom.getInstance("SHA1PRNG");
			//设置上**种子
			secureRandom.setSeed(KEY_STR.getBytes());
			//初始化基于SHA1的算法对象
			generator.init(secureRandom);
			//生成**对象
			key=generator.generateKey();
			generator=null;
		}catch(Exception e){
			throw new RuntimeException(e);
		}
	}
	
	/**
	 * 加密
	 * @param str
	 * @return
	 */
	public static String getEncryptString(String str){
		//基于BASE64编码，接收byte[]并转换成String
		BASE64Encoder base64Encoder=new BASE64Encoder();
		try {
			// 按UTF8编码
			byte[] bytes = str.getBytes(CHARSETNAME);
			// 获取加密对象
			Cipher cipher = Cipher.getInstance(ALGORITHM);
			// 初始化密码信息
			cipher.init(Cipher.ENCRYPT_MODE, key);
			// 加密
			byte[] doFinal = cipher.doFinal(bytes);
			// byte[]to encode好的String并返回
			return base64Encoder.encode(doFinal);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	/**
	 * 解密
	 * 
	 * @param str
	 * @return
	 */
	public static String getDecryptString(String str) {
		// 基于BASE64编码，接收byte[]并转换成String
		BASE64Decoder base64decoder = new BASE64Decoder();
		try {
			// 将字符串decode成byte[]
			byte[] bytes = base64decoder.decodeBuffer(str);
			// 获取解密对象
			Cipher cipher = Cipher.getInstance(ALGORITHM);
			// 初始化解密信息
			cipher.init(Cipher.DECRYPT_MODE, key);
			// 解密
			byte[] doFinal = cipher.doFinal(bytes);
			// 返回解密之后的信息
			return new String(doFinal, CHARSETNAME);
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	
	public static void main(String[] args) {
		//加密
		System.out.println(getEncryptString("加密的字符串"));
		//解密
		System.out.println(getDecryptString(getEncryptString("加密的字符串")));

	}
}