java操作文件加密与解密

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

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

public class EncryptGen {

 // static boolean debug =false ;

 // 加密KEY不能随便改动
 static final byte[] KEYVALUE = "6^)(9-p35@%3#4S!4S0)$Y%%^&5(j.&^&o(*0)$Y%!#O@*GpG@=+@j.&6^)(0-=+"
   .getBytes();

 static final int BUFFERLEN = 512;

 public EncryptGen() {
 }

 /**
  * 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:\\aaa\\aa.txt");
   String newFile = new String("C:\\aaa\\aa_en.txt");
   encryptFile(oldFile, newFile);

     System.out.println("ok");
  } catch (Exception e) {
   e.printStackTrace();
  }

 }

}

评论

2 楼 pengyan5945 2012-02-20  

pengyan5945 写道

while ((temp = inputStream.read(buffer)) != -1) {
			for (int i = 0,index = 0; i < temp; i++,index++) {
				buffer[i] ^= encryptKey[index];
				outputStream.write(buffer[i]);
			}
		}

发现我的有问题，呵呵。现在才明白！

1 楼 pengyan5945 2012-02-20  

while ((temp = inputStream.read(buffer)) != -1) {
			for (int i = 0,index = 0; i < temp; i++,index++) {
				buffer[i] ^= encryptKey[index];
				outputStream.write(buffer[i]);
			}
		}