采用Cipher DES针对文件加密、解密

由于经常用一些加密或者解密文件的，所以写了一个简单的采用Cipher DES针对文件加密、解密的工具类，记录一下，防止以后忘记了！

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.security.Key;
import java.util.ArrayList;
import java.util.List;

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

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/***
* Des文件加密解密
*/
public class FileDeEncrypt {
private static final Logger LOG = LoggerFactory.getLogger(FileDeEncrypt. class );


public FileDeEncrypt(String keyStr) {
genKey(keyStr);
initCipher();
}

private Key key;
// 解密密码
private Cipher cipherDecrypt;
// 加密密码
private Cipher cipherEncrypt;


/**
* 加密文件的核心
*
* @param file
* 要加密的文件
* @param destFile
* 加密后存放的文件名
*/
public boolean encryptFile(String srcFileName, String destFileName) {
try {
InputStream is = new FileInputStream(srcFileName);
OutputStream out = new FileOutputStream(destFileName);

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();
LOG.info( "文件{}加密完成，加密后的文件是:{}" , srcFileName, destFileName);
return true ;
}
catch (Exception e) {
LOG.error( "加密文件{}出现异常" , srcFileName, e.getMessage());
e.printStackTrace();
return false ;
}
}


/***
* 解密文件
*
* @param destFile
*/
public List decryptFileContent(String fileName) {
List list = new ArrayList();
try {
InputStream is = new FileInputStream(fileName);
CipherInputStream cis = new CipherInputStream(is, cipherDecrypt);
BufferedReader reader = new BufferedReader( new InputStreamReader(cis));
String line = null ;
while ((line = reader.readLine()) != null ) {
list.add(line);
}
reader.close();
cis.close();
is.close();
LOG.info( "文件{}解密完成" , fileName);
}
catch (Exception e) {
LOG.error( "解密文件{}出现异常" , fileName, e.getMessage());
e.printStackTrace();
}
return list;
}

/**
* 解密文件，返回reader
* @param fileName
* @return
*/
public BufferedReader decryptFile(String fileName) {
BufferedReader reader = null ;
try {
InputStream is = new FileInputStream(fileName);
CipherInputStream cis = new CipherInputStream(is, cipherDecrypt);
reader = new BufferedReader( new InputStreamReader(cis));
}
catch (Exception e) {
LOG.error( "解密文件{}出现异常" , fileName, e.getMessage());
e.printStackTrace();
}
return reader;
}


private void initCipher() {
try {
// 加密的cipher
cipherEncrypt = Cipher.getInstance( "DES" );
cipherEncrypt.init(Cipher.ENCRYPT_MODE, key);
// 解密的cipher
cipherDecrypt = Cipher.getInstance( "DES" );
cipherDecrypt.init(Cipher.DECRYPT_MODE, key);
}
catch (Exception e) {
LOG.info( "加密初始化出现异常:{}" , e.getMessage());
e.printStackTrace();
}
}


/**
* 自定义一个key
*
* @param string
*/
public void genKey(String keyRule) {
// Key key = null;
byte [] keyByte = keyRule.getBytes();
// 创建一个空的八位数组,默认情况下为0
byte [] byteTemp = new byte [ 8 ];
// 将用户指定的规则转换成八位数组
for ( int i = 0 ; i < byteTemp.length && i < keyByte.length; i++) {
byteTemp[i] = keyByte[i];
}
key = new SecretKeySpec(byteTemp, "DES" );
}


/***
* 测试加密解密
*
* @param args
*/
public static void main(String[] args) {
FileDeEncrypt deEncrypt = new FileDeEncrypt( "STP FILE DE-ENCRYPT" );
deEncrypt.encryptFile( "pom.xml" , "pom.bin" );
List list = deEncrypt.decryptFileContent( "pom.bin" );
for (String str : list) {
System.out.println(str);
}
}
}

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