JAVA采用DES算法进行加密解密文件

package key;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.Key;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;

public class key {
Key key;
public key(String str) {
getKey(str);//生成密匙
}
/**
* 根据参数生成KEY
*/
public void getKey(String strKey) {
try {
KeyGenerator _generator = KeyGenerator.getInstance("DES");
_generator.init(new SecureRandom(strKey.getBytes()));
this.key = _generator.generateKey();
_generator = null;
} catch (Exception e) {
throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);
}
}

/**
* 文件file进行加密并保存目标文件destFile中
*
* @param file   要加密的文件 如c:/test/srcFile.txt
* @param destFile 加密后存放的文件名 如c:/加密后文件.txt
*/
public void encrypt(String file, String destFile) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
// cipher.init(Cipher.ENCRYPT_MODE, getKey());
cipher.init(Cipher.ENCRYPT_MODE, this.key);
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(destFile);
CipherInputStream cis = new CipherInputStream(is, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = cis.read(buffer)) > 0) {
out.write(buffer, 0, r);
}
cis.close();
is.close();
out.close();
}
/**
* 文件采用DES算法解密文件
*
* @param file 已加密的文件 如c:/加密后文件.txt
*         * @param destFile
*         解密后存放的文件名 如c:/ test/解密后文件.txt
*/
public void decrypt(String file, String dest) throws Exception {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.DECRYPT_MODE, this.key);
InputStream is = new FileInputStream(file);
OutputStream out = new FileOutputStream(dest);
CipherOutputStream cos = new CipherOutputStream(out, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = is.read(buffer)) >= 0) {
System.out.println();
cos.write(buffer, 0, r);
}
cos.close();
out.close();
is.close();
}
public static void main(String[] args) throws Exception {
key td = new key("aaa");

td.decrypt("D:/gx.txt", "d:/r1.txt"); //解密

}
}