java写的DES加密解密的小例子

运行代码：

package com.DESUtil;

import java.security.NoSuchAlgorithmException;
import java.security.Security;

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

import com.sun.crypto.provider.SunJCE;

/**
 * Description 处理字符串加密解密的公用类
 * @author Administrator
 *
 */
public class DESEDE {
	
	private static final String Algorithm = "DESede";

	public DESEDE() {
	} 

	private static byte[] encryptMode(byte keybyte[], byte src[]) {
		try {
			javax.crypto.SecretKey deskey = new SecretKeySpec(keybyte, "DESede");
			Cipher c1 = Cipher.getInstance("DESede");
			c1.init(1, deskey);
			return c1.doFinal(src);
		} catch (NoSuchAlgorithmException e1) {
			e1.printStackTrace();
		} catch (NoSuchPaddingException e2) {
			e2.printStackTrace();
		} catch (Exception e3) {
			e3.printStackTrace();
		}
		return null;
	}

	private static byte[] decryptMode(byte keybyte[], byte src[]) {
		try {
			javax.crypto.SecretKey deskey = new SecretKeySpec(keybyte, "DESede");
			Cipher c1 = Cipher.getInstance("DESede");
			c1.init(2, deskey);
			return c1.doFinal(src);
		} catch (NoSuchAlgorithmException e1) {
			e1.printStackTrace();
		} catch (NoSuchPaddingException e2) {
			e2.printStackTrace();
		} catch (Exception e3) {
			e3.printStackTrace();
		}
		return null;
	}

	private static String byte2hex(byte b[]) {
		String hs = "";
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			stmp = Integer.toHexString(b[n] & 0xff);
			if (stmp.length() == 1)
				hs = hs + "0" + stmp;
			else
				hs = hs + stmp;
		}

		return hs.toUpperCase();
	}

	public static byte[] hex2byte(String hex) throws IllegalArgumentException {
		if (hex.length() % 2 != 0)
			throw new IllegalArgumentException();
		char arr[] = hex.toCharArray();
		byte b[] = new byte[hex.length() / 2];
		int i = 0;
		int j = 0;
		for (int l = hex.length(); i < l;) {
			String swap = "" + arr[i++] + arr[i];
			int byteint = Integer.parseInt(swap, 16) & 0xff;
			b[j] = (new Integer(byteint)).byteValue();
			i++;
			j++;
		}

		return b;
	}
	/**
	 * 字符串加密
	 * @param sourceCode 要加密的字符串
	 * +
	 * @return
	 */
	public static String encryptIt(String sourceCode) {
		Security.addProvider(new SunJCE());
		byte keyBytes[] = { 17, 34, 79, 88, -120, 16, 64, 56, 40, 37, 121, 81,
				-53, -35, 85, 102, 119, 41, 116, -104, 48, 64, 54, -30 };
		byte encoded[] = encryptMode(keyBytes, sourceCode.getBytes());
		return byte2hex(encoded);
	}
	/**
	 * 字符串解密
	 * @param encodedCode 要解密的字符串
	 * @return
	 */
	public static String decryptIt(String encodedCode) {
		Security.addProvider(new SunJCE());
		byte keyBytes[] = { 17, 34, 79, 88, -120, 16, 64, 56, 40, 37, 121, 81,
				-53, -35, 85, 102, 119, 41, 116, -104, 48, 64, 54, -30 };
		byte encoded[] = decryptMode(keyBytes, hex2byte(encodedCode));
		return new String(encoded);
	}
	
	public static void main(String args[]) {
		String str="1234";
		String str1=encryptIt(str);
		System.out.println("加密1234:"+str1);
		String str2=decryptIt("D4F7DDF6D2B9A0E7");
		//System.out.println("str2="+str2);
		if(str.equals(str2)){
			System.out.println("加密解密成功了");
		}
		System.out.println("解密9F7798E2D49AC78C7C78DE1DA63CD426:"+decryptIt("9F7798E2D49AC78C7C78DE1DA63CD426"));
	}
}

运行截图：