java DES暗号解読ファイル

本論文の転送先:http://blog.csdn.net/springsky_/アート/detail/7873909
Android開発中やjava開発中に、常にいくつかの暗号化やファイルを解読しています。以下は最近テストしたDES暗号解読ファイルの方式です。記録してください。後で忘れないようにしてください。
下に直接コードを貼ってください。詳しいコメントは全部書いてあります。

package com.spring.des;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

/***
 * Des      
 * 
 * @author spring sky<br>
 * Email:[email protected]<br>
 * QQ:840950105
 * 
 */
public class DesFileEncrypt {
	/**
	 *           
	 */
	public static String[] filePath = { "D:/sasdfp.sql" };
	/**
	 *           
	 */
	public static String[] outFilePath = new String[filePath.length];
	private static final String KEY = "spring sky";

	public DesFileEncrypt() {
		super();
		getKey(KEY);
		initCipher();
		//         
		crateEncryptFile();
	}

	private Key key;
	
	/***
	 *     
	 */
	private Cipher cipherDecrypt;
	/**
	 *     
	 */
	private Cipher cipherEncrypt;

	/**
	 *                 
	 * */
	private void crateEncryptFile() {
		String outPath = null;
		for (int i = 0; i < filePath.length; i++) {
			try {
				outPath = filePath[i].substring(0,filePath[i].lastIndexOf("."))+".bin";
				encrypt(filePath[i], outPath);
				outFilePath[i] = outPath;
				System.out.println(filePath[i]+"    ，       :"+outFilePath[i]);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		System.out.println("=========================    =======================");
		
	}

	/**
	 *        
	 * 
	 * @param file
	 *                  
	 * @param destFile
	 *                     
	 */
	public void encrypt(String file, String destFile) throws Exception {
		InputStream is = new FileInputStream(file);
		OutputStream out = new FileOutputStream(destFile);

		CipherInputStream cis = new CipherInputStream(is, cipherEncrypt);
		byte[] buffer = new byte[1024];
		int r;
		while ((r = cis.read(buffer)) > 0) {
			out.write(buffer, 0, r);
		}
		cis.close();
		is.close();
		out.close();
	}

	/***
	 *     
	 * @param destFile
	 */
	public void decrypt(String destFile) {
		try {
			InputStream is = new FileInputStream(destFile);
			CipherInputStream cis = new CipherInputStream(is, cipherDecrypt);
			BufferedReader reader = new BufferedReader(new InputStreamReader(
					cis));
			String line = null;
			while ((line = reader.readLine()) != null) {
				System.out.println(line);
			}
			reader.close();
			cis.close();
			is.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private void initCipher() {
		try {
			//    cipher
			cipherEncrypt = Cipher.getInstance("DES");
			cipherEncrypt.init(Cipher.ENCRYPT_MODE, this.key);
			//    cipher
			cipherDecrypt = Cipher.getInstance("DES");
			cipherDecrypt.init(Cipher.DECRYPT_MODE, this.key);
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		}
	}

	/**
	 *      key
	 * 
	 * @param string
	 */
	public Key getKey(String keyRule) {
		// Key key = null;
		byte[] keyByte = keyRule.getBytes();
		//           ,      0
		byte[] byteTemp = new byte[8];
		//                
		for (int i = 0; i < byteTemp.length && i < keyByte.length; i++) {
			byteTemp[i] = keyByte[i];
		}
		key = new SecretKeySpec(byteTemp, "DES");
		return key;
	}

	/**
	 *     
	 * 
	 * @return
	 */
	public Cipher getCipherEdcrypt() {
		return cipherDecrypt;
	}

	/**
	 *     
	 * 
	 * @return
	 */
	public Cipher getCipherEncrypt() {
		return cipherEncrypt;
	}

	/***
	 *       
	 * @param args
	 */
	public static void main(String[] args) {
		DesFileEncrypt desFileEncrypt = new DesFileEncrypt();
		desFileEncrypt.decrypt(outFilePath[0]);  //                 
	}
}