本文實例講述了Java實現的RSA加密解密算法。分享給大家供大家參考，具體如下：
import java.awt.AlphaComposite;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.Image;import java.awt.RenderingHints;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.security.Key;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.SecureRandom;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import javax.crypto.Cipher;public class RSAUtils{ public static String makekeyfile(String pubkeyfile, String prikeyfile) { String result = "生成公私鑰文件失敗"; try{ // KeyPairGenerator用於生成公私鑰對，基於RSA算法生成對象KeyPairGenerator gen = KeyPairGenerator.getInstance("RSA"); // 初始化密鑰對生成器，密鑰大小為1024位gen.initialize(1024);// //生成強隨機數// SecureRandom random = new SecureRandom();// gen.initialize(1024,random); // 生成一個密鑰對，保存在pair中KeyPair pair = gen.generateKeyPair(); // 得到私鑰RSAPrivateKey priKey = (RSAPrivateKey) pair.getPrivate(); // 得到公鑰RSAPublicKey pubKey = (RSAPublicKey) pair.getPublic(); // 生成私鑰文件ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(prikeyfile)); os.writeObject(priKey); os.flush(); os.close(); //生成公鑰文件os = new ObjectOutputStream(new FileOutputStream(pubkeyfile)); os.writeObject(pubKey); os.flush(); os.close(); result = "生成公鑰文件【"+pubkeyfile+"】生成私鑰文件【"+prikeyfile+"】"; }catch(Exception e){ e.printStackTrace(); } return result; } public static void main(String[] args) { try{ String pubfile = "F:/images/pub.key"; String prifile = "F:/images/pri.key"; String result = null; //result = makekeyfile(pubfile, prifile); result = markPuPra(pubfile, prifile); System.out.println(result); }catch(Exception e){ e.printStackTrace(); } } public static String markPuPra(String pubfile,String prifile){ String results = "加解密出錯"; try{ ObjectInputStream os = new ObjectInputStream(new FileInputStream(pubfile)); RSAPublicKey pubkey = (RSAPublicKey) os.readObject(); os.close(); os = new ObjectInputStream(new FileInputStream(prifile)); RSAPrivateKey prikey = (RSAPrivateKey) os.readObject(); os.close(); String utf = "UTF-8"; String msg = "##中國%%的）人@+_"; // 使用公鑰加密私鑰解密System.out.println("原文: " + msg); byte[] puk = handleData(pubkey, msg.getBytes(utf), 1); System.out.println("加密後文件數據: " + new String(puk, utf)); byte[] dpuk = handleData(prikey, puk, 0); System.out.println("解密後文件數據: " + new String(dpuk, utf)); msg = "jd#我0們的￥人+=#新"; // 使用私鑰加密公鑰解密System.out.println("原文: " + msg); byte[] prk = handleData(prikey, msg.getBytes(utf), 1); System.out.println("加密後文件數據: " + new String(prk, utf)); byte[] dprk = handleData(pubkey, prk, 0); System.out.println("解密後文件數據: " + new String(dprk, utf)); results = "加解密完成"; }catch(Exception e){ e.printStackTrace(); } return results; } /** * * @param k * @param data * @param encrypt 1 加密0解密* @return * @throws Exception */ public static byte[] handleData(Key key, byte[] data, int type) throws Exception { if (key != null) { Cipher ci = Cipher.getInstance("RSA"); if (type == 1) { ci.init(Cipher.ENCRYPT_MODE, key); byte[] res = ci.doFinal(data); return res; } if (type == 0) { ci.init(Cipher.DECRYPT_MODE, key); byte[] res = ci.doFinal(data); return res; } } return null; }}PS：關於加密解密感興趣的朋友還可以參考本站在線工具：
文字在線加密解密工具（包含AES、DES、RC4等）：
http://tools.VeVB.COm/password/txt_encode
MD5在線加密工具:
http://tools.VeVB.COm/password/CreateMD5Password
在線散列/哈希算法加密工具:
http://tools.VeVB.COm/password/hash_encrypt
在線MD5/hash/SHA-1/SHA-2/SHA-256/SHA-512/SHA-3/RIPEMD-160加密工具：
http://tools.VeVB.COm/password/hash_md5_sha
在線sha1/sha224/sha256/sha384/sha512加密工具：
http://tools.VeVB.COm/password/sha_encode
更多關於java相關內容感興趣的讀者可查看本站專題：《Java數學運算技巧總結》、《Java數據結構與算法教程》、《Java字符與字符串操作技巧總結》、《Java操作DOM節點技巧總結》和《Java緩存操作技巧匯總》
希望本文所述對大家java程序設計有所幫助。