java实现文件加密

package org.test; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; import java.security.Key; import java.security.Security; import javax.crypto.Cipher; import javax.crypto.CipherInputStream; import javax.crypto.CipherOutputStream; import javax.crypto.KeyGenerator; public class DESCryptoTest { public static void main(String[] args) { Security.addProvider(new com.sun.crypto.provider.SunJCE()); // Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); KeyGenerator kg = null; try { //指定算法,这里为DES;如果想用Blowfish算法,则用 getInstance("Blowfish") //BouncyCastle基本上支持所有通用标准算法 kg = KeyGenerator.getInstance("DES"); //指定密钥长度,长度越高,加密强度越大 kg.init(56); //产生密钥 Key key = kg.generateKey(); System.out.println("Key format: " + key.getFormat()); System.out.println("Key algorithm: " + key.getAlgorithm()); //加密要用Cipher来实现 Cipher cipher = Cipher.getInstance("DES"); System.out.println("Cipher provider: " + cipher.getProvider()); System.out.println("Cipher algorithm: " + cipher.getAlgorithm()); byte[] data = "Hello World!".getBytes(); System.out.println("Original data : [" + data.length + "]" + new String(data)); //设置加密模式 cipher.init(Cipher.ENCRYPT_MODE, key); byte[] result = cipher.doFinal(data); System.out.println("Encrypted data: [" + result.length + "]" + new String(result)); //设置解密模式 cipher.init(Cipher.DECRYPT_MODE, key); byte[] original = cipher.doFinal(result); System.out.println("Decrypted data: [" + original.length + "]" + new String(original)); String filename = "bin\\Order.xml"; //读入并加密文件 try { //输入流 cipher.init(Cipher.ENCRYPT_MODE, key); BufferedInputStream in = new BufferedInputStream(new FileInputStream(filename)); //输出流 CipherOutputStream out = new CipherOutputStream(new BufferedOutputStream(new FileOutputStream("bin\\Order_Encryption.xml")), cipher); int i; do { i = in.read(); if (i != -1) out.write(i); } while (i != -1); in.close(); out.close(); System.out.println("加密文件完成！"); } catch (Exception ey5) { System.out.println("Error when encrypt the file"); ey5.printStackTrace(); System.exit(0); } try { cipher.init(Cipher.DECRYPT_MODE, key); //输出流 BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("bin\\Order_Decryption.xml")); //输入流 CipherInputStream in = new CipherInputStream(new BufferedInputStream( new FileInputStream("bin\\Order_Encryption.xml")), cipher); int i; do { i = in.read(); if (i != -1) out.write(i); } while (i != -1); in.close(); out.close(); System.out.println("解密文件完成！"); } catch (Exception ey5) { System.out.println("Error when encrypt the file"); ey5.printStackTrace(); System.exit(0); } } catch (Exception e) { e.printStackTrace(); } } }