package  des; 

import  java.io. * ; 
import  java.nio. * ; 
import  java.nio.channels.FileChannel; 

public   class  FileDES{ 
private   static   final   boolean  enc = true ;  // 加密 
private   static   final   boolean  dec = false ;  // 解密 

private  String srcFileName; 
private  String destFileName; 
private  String inKey; 
private   boolean  actionType; 
private  File srcFile; 
private  File destFile; 
private  Des des; 

private   void  analyzePath(){ 
String dirName; 
int  pos = srcFileName.lastIndexOf( " / " ); 
dirName = srcFileName.substring( 0 ,pos); 
File dir = new  File(dirName); 
if  ( ! dir.exists()){ 
System.err.println(dirName + "  is not exist " ); 
System.exit( 1 ); 
} else   if ( ! dir.isDirectory()){ 
System.err.println(dirName + "  is not a directory " ); 
System.exit( 1 ); 
} 

pos = destFileName.lastIndexOf( " / " ); 
dirName = destFileName.substring( 0 ,pos); 
dir = new  File(dirName); 
if  ( ! dir.exists()){ 
if ( ! dir.mkdirs()){ 
System.out.println ( " can not creat directory: " + dirName); 
System.exit( 1 ); 
} 
} else   if ( ! dir.isDirectory()){ 
System.err.println(dirName + "  is not a directory " ); 
System.exit( 1 ); 
} 
} 

private   static   int  replenish(FileChannel channel,ByteBuffer buf)  throws  IOException{ 
long  byteLeft = channel.size() - channel.position(); 
if (byteLeft == 0L ) 
return   - 1 ; 
buf.position( 0 ); 
buf.limit(buf.position() + (byteLeft < 8   ?  ( int )byteLeft : 8 )); 
return  channel.read(buf); 
} 

private   void  file_operate( boolean  flag){ 
des = new  Des(inKey); 
FileOutputStream outputFile = null ; 
try  { 
outputFile = new  FileOutputStream(srcFile, true ); 
} catch  (java.io.FileNotFoundException e) { 
e.printStackTrace(System.err); 
} 
FileChannel outChannel = outputFile.getChannel(); 

try { 
if (outChannel.size() % 2 != 0 ){ 
ByteBuffer bufTemp = ByteBuffer.allocate( 1 ); 
bufTemp.put(( byte ) 32 ); 
bufTemp.flip(); 
outChannel.position(outChannel.size()); 
outChannel.write(bufTemp); 
bufTemp.clear(); 
} 
} catch (Exception ex){ 
ex.printStackTrace(System.err); 
System.exit( 1 ); 
} 
FileInputStream inFile = null ; 
try { 
inFile = new  FileInputStream(srcFile); 
} catch (java.io.FileNotFoundException e){ 
e.printStackTrace(System.err); 
// System.exit(1); 
} 
outputFile = null ; 
try  { 
outputFile = new  FileOutputStream(destFile, true ); 
} catch  (java.io.FileNotFoundException e) { 
e.printStackTrace(System.err); 
} 

FileChannel inChannel = inFile.getChannel(); 
outChannel = outputFile.getChannel(); 


ByteBuffer inBuf = ByteBuffer.allocate( 8 ); 
ByteBuffer outBuf = ByteBuffer.allocate( 8 ); 

try { 
String srcStr; 
String destStr; 
while ( true ){ 

if  (replenish(inChannel,inBuf) ==- 1 )  break ; 
srcStr = ((ByteBuffer)(inBuf.flip())).asCharBuffer().toString(); 
inBuf.clear(); 
if  (flag) 
destStr = des.enc(srcStr,srcStr.length()); 
else  
destStr = des.dec(srcStr,srcStr.length()); 
outBuf.clear(); 
if  (destStr.length() == 4 ){ 
for  ( int  i  =   0 ; i < 4 ; i ++ ) { 
outBuf.putChar(destStr.charAt(i)); 
} 
outBuf.flip(); 
} else { 
outBuf.position( 0 ); 
outBuf.limit( 2 * destStr.length()); 
for  ( int  i  =   0 ; i < destStr.length(); i ++ ) { 
outBuf.putChar(destStr.charAt(i)); 
} 
outBuf.flip(); 
} 

try  { 
outChannel.write(outBuf); 
outBuf.clear(); 
} catch  (java.io.IOException ex) { 
ex.printStackTrace(System.err); 
} 
} 
System.out.println (inChannel.size()); 
System.out.println (outChannel.size()); 
System.out.println ( " EoF reached. " ); 
inFile.close(); 
outputFile.close(); 
} catch (java.io.IOException e){ 
e.printStackTrace(System.err); 
System.exit( 1 ); 
} 
} 

public  FileDES(String srcFileName,String destFileName,String inKey, boolean  actionType){ 
this .srcFileName = srcFileName; 
this .destFileName = destFileName; 
this .actionType = actionType; 
analyzePath(); 
srcFile = new  File(srcFileName); 
destFile = new  File(destFileName); 
this .inKey = inKey; 
if  (actionType == enc) 
file_operate(enc); 
else  
file_operate(dec); 
} 


public   static   void  main(String[] args){ 
String file1 = System.getProperty( " user.dir " ) + " /111.doc " ; 
String file2 = System.getProperty( " user.dir " ) + " /222.doc " ; 
String file3 = System.getProperty( " user.dir " ) + " /333.doc " ; 
String passWord = " 1234ABCD " ; 
FileDES fileDes = new  FileDES(file1,file2,passWord, true ); 
FileDES fileDes1 = new  FileDES(file2,file3,passWord, false ); 
}