java加密-优快云博客

本文提供了一个使用Java实现的加密解密示例，包括MD5、SHA-1散列算法及DES对称加密算法的应用。通过具体代码展示了如何生成散列值、加密和解密文本。

package com.sinosoft.test;

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.security.spec.KeySpec;
import java.util.BitSet;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

public class Main {

// DES密钥必须是8的倍数
private static final String serectKey = "1234567j";

public static void main(String[] args) {

}

public static String md5(String content) {
  try {
   MessageDigest messageDigest = MessageDigest.getInstance("MD5");
   messageDigest.update(content.getBytes("utf-8"));
   byte[] bytes = messageDigest.digest();
   BigInteger bigInteger = new BigInteger(bytes);
   return String.valueOf(bigInteger);
  } catch (Exception e) {
   e.printStackTrace();
  }
  return "";
}

public static String sha(String content) {
  try {
   MessageDigest messageDigest = MessageDigest.getInstance("SHA-1");
   messageDigest.update(content.getBytes("utf-8"));
   byte[] bytes = messageDigest.digest();
   BigInteger bigInteger = new BigInteger(bytes);
   return String.valueOf(bigInteger);
  } catch (Exception e) {
   e.printStackTrace();
  }
  return "";
}

private static byte[] bytes;

public static void encryDes(String content) {
  try {
   DESKeySpec desKeySpec = new DESKeySpec(serectKey.getBytes("utf-8"));
   SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("DES");
   SecretKey sk = secretKeyFactory.generateSecret(desKeySpec);
   Cipher cipher = Cipher.getInstance("DES");
   cipher.init(Cipher.ENCRYPT_MODE,sk,new SecureRandom());
   bytes = cipher.doFinal(content.getBytes("utf-8"));
   System.out.println(new String(bytes,"utf-8"));
  } catch (Exception e) {
   e.printStackTrace();
  }
}

public static void decryDes(byte[] bytes) {
  try {
   DESKeySpec desKeySpec = new DESKeySpec(serectKey.getBytes("utf-8"));
   SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("DES");
   SecretKey sk = secretKeyFactory.generateSecret(desKeySpec);
   Cipher cipher = Cipher.getInstance("DES");
   cipher.init(Cipher.DECRYPT_MODE,sk,new SecureRandom());
   System.out.println(new String(cipher.doFinal(bytes),"utf-8"));
  } catch (Exception e) {
   e.printStackTrace();
  }
}
}