java基于DES对称的和RSA非对称的加密解密

package com; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import javax.crypto.Cipher; public class RSA { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub try{ KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA"); //创建‘密匙对’生成器 KeyPair kp = kpg.genKeyPair(); PublicKey public_key = kp.getPublic(); //获得公匙 PrivateKey private_key = kp.getPrivate(); //获得私匙 Cipher cp = Cipher.getInstance("RSA"); //创建密码器 cp.init(Cipher.ENCRYPT_MODE, public_key); //初始化 第一个参数:为1时为加密,为2时为解密 String str = "RSA非对称密码体系"; byte [] ptext = str.getBytes("GBK"); byte [] ctext = cp.doFinal(ptext); //加密 cp.init(Cipher.DECRYPT_MODE, private_key); //初始化 第一个参数:为1时为加密,为2时为解密 byte [] mtext = cp.doFinal(ctext); //解密 System.out.println("公钥是:"+new String(public_key.getEncoded(),"GBK")); System.out.println("私钥是:"+new String(private_key.getEncoded(),"GBK")); System.out.println("秘文是:"+new String(ctext,"GBK")); String result = new String(mtext, "GBK"); System.out.println("明文是:"+result); }catch(Exception e){ e.printStackTrace(); } } }