文件加解密

package com.test;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

/**
 * 加密解密类
 * 
 * @author
 * @version 1.00
 */

public class Test {

	// static boolean debug =false ;

	// 加密KEY不能随便改动
	static final byte[] KEYVALUE = "11111111111111111111"
			.getBytes();

	static final int BUFFERLEN = 512;

	public Test() {
	}

	/**
	 * 对文件进行加密
	 * 
	 * @param String
	 *            oldFile 原始要加密的文件
	 * @param String
	 *            newFile 加密后的文件
	 * @return
	 */
	public static void encryptFile(String oldFile, String newFile)
			throws Exception {
		FileInputStream in = new FileInputStream(oldFile);
		File file = new File(newFile);
		if (!file.exists())
			file.createNewFile();
		FileOutputStream out = new FileOutputStream(file);
		int c, pos, keylen;
		pos = 0;
		keylen = KEYVALUE.length;
		byte buffer[] = new byte[BUFFERLEN];
		while ((c = in.read(buffer)) != -1) {
			for (int i = 0; i < c; i++) {
				buffer[i] ^= KEYVALUE[pos];
				out.write(buffer[i]);
				pos++;
				if (pos == keylen)
					pos = 0;
			}
		}
		in.close();
		out.close();
	}

	/**
	 * 对文件进行解密
	 * 
	 * @param String
	 *            oldFile 原始要解密的文件
	 * @param String
	 *            newFile 解密后的文件
	 * @return
	 */
	public static void decryptFile(String oldFile, String newFile)
			throws Exception {
		FileInputStream in = new FileInputStream(oldFile);
		File file = new File(newFile);
		if (!file.exists())
			file.createNewFile();
		FileOutputStream out = new FileOutputStream(file);
		int c, pos, keylen;
		pos = 0;
		keylen = KEYVALUE.length;
		byte buffer[] = new byte[BUFFERLEN];
		while ((c = in.read(buffer)) != -1) {
			for (int i = 0; i < c; i++) {
				buffer[i] ^= KEYVALUE[pos];
				out.write(buffer[i]);
				pos++;
				if (pos == keylen)
					pos = 0;
			}
		}
		in.close();
		out.close();
	}

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try {
			// debug =false ;

			String oldFile = new String("c:/test.doc");
			String newFile = new String("c:/file2.doc");
			String file3 = new String("c:/file3.doc");
			encryptFile(oldFile, newFile);
			
			decryptFile(newFile, file3);
			
			System.out.println("ok");
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}