本文实例讲述了Java实现的DES加密解密工具类。分享给大家供大家参考，具体如下：
一个工具类，很常用，不做深入研究了，那来可直接用
DesUtil.java
package lsy;
import java.security.Key;
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;
public class DesUtil {
/**
* @param args
*/
public static void main(String[] args) {
//以下是加密方法algorithm="AES"的测试
System.out.println(DesUtil.getInstance("lushuaiyin").getEnCodeString("hello"));
//输出 LDewGAZkmWHeYFjBz56ylw==
//将上面的密文解密：
System.out.println(DesUtil.getInstance("lushuaiyin").getDecodeString("LDewGAZkmWHeYFjBz56ylw=="));
//输出 hello
//改变密钥测试
System.out.println(DesUtil.getInstance("suolong").getEnCodeString("hello"));
//输出 /RLowOJ+Fr3KdMcdJeNatg==
System.out.println(DesUtil.getInstance("suolong").getDecodeString("/RLowOJ+Fr3KdMcdJeNatg=="));
//输出 hello
//如果使用不正确的密钥解密，将会：
System.out.println(DesUtil.getInstance("suolong").getDecodeString("LDewGAZkmWHeYFjBz56ylw=="));
}
private SecretKey key=null;//密钥
//定义 加密算法,可用 DES,DESede,Blowfish,AES
//不同的加密方式结果会不同
private static String algorithm="AES";
private static DesUtil desUtil=null;
public DesUtil(){}
public static DesUtil getInstance(String strKey){
desUtil=new DesUtil();
desUtil.createKey(strKey);
return desUtil;
}
/**
* algorithm 算法
* @param strKey
*/
public void createKey(String strKey){
try{
KeyGenerator kg=KeyGenerator.getInstance(DesUtil.algorithm);
byte[] bt=strKey.getBytes("UTF-8");
SecureRandom sr=new SecureRandom(bt);
kg.init(sr);
this.setKey(kg.generateKey());
}catch(Exception e){
}
}
/**
* 加密方法，返回密文
* cipher 密码
* @param dataStr
*/
public String getEnCodeString(String dataStr){
byte[] miwen=null;//密文
byte[] mingwen=null;//明文
Cipher cipher;
String result="";//密文字符串
try{
mingwen=dataStr.getBytes("UTF-8");
cipher=Cipher.getInstance(DesUtil.algorithm);
cipher.init(Cipher.ENCRYPT_MODE, this.getKey());
miwen=cipher.doFinal(mingwen);
BASE64Encoder base64en = new BASE64Encoder();
result=base64en.encodeBuffer(miwen);//或者可以用下面的方法得到密文，结果是不一样的，都可以正常解密
// result=byte2hex(miwen);//密文结果类似2C:37:B0:18:06:64:99:61:DE:60:58:C1:CF:9E:B2:97
}catch(Exception e){
e.printStackTrace();
}
return result;
}
/**
* 解密方法，返回明文
* @param codeStr
* @return
*/
public String getDecodeString(String codeStr){
BASE64Decoder base64De = new BASE64Decoder();
byte[] miwen=null;
byte[] mingwen=null;
String resultData="";//返回的明文
Cipher cipher;
try{
miwen=base64De.decodeBuffer(codeStr);
cipher=Cipher.getInstance(DesUtil.algorithm);
cipher.init(Cipher.DECRYPT_MODE, this.getKey());
mingwen=cipher.doFinal(miwen);
resultData = new String(mingwen,"UTF-8");
}catch(Exception e){
return "密钥不正确或其他原因导致异常，无法解密！";
}
return resultData;
}
//二行制转字符串
public String byte2hex(byte[] b) {
String hs = "";
String stmp = "";
for (int n = 0; n < b.length; n++) {
stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
if (stmp.length() == 1)
hs = hs + "0" + stmp;
else
hs = hs + stmp;
if (n < b.length - 1)
hs = hs + ":";
}
return hs.toUpperCase();
}
public SecretKey getKey() {
return key;
}
public void setKey(SecretKey key) {
this.key = key;
}
public static String getAlgorithm() {
return algorithm;
}
public static void setAlgorithm(String algorithm) {
algorithm = algorithm;
}
}
运行结果：
LDewGAZkmWHeYFjBz56ylw==
hello
/RLowOJ+Fr3KdMcdJeNatg==
hello
密钥不正确或其他原因导致异常，无法解密！
PS：关于加密解密感兴趣的朋友还可以参考本站在线工具：
在线MD5/hash/SHA-1/SHA-2/SHA-256/SHA-512/SHA-3/RIPEMD-160加密工具：/password/hash_md5_sha
希望本文所述对大家java程序设计有所帮助。
