des加密代码java 加密解密 java

用java实现des算法分类:电脑/网络程序设计其他编程语言
问题描述:
各位好,请求各位java学习者帮助钉解决这个问题 。
我想用des算法对我的名字进行加密
我也在网上下载了des算法 , 包括FileDES,SubKey,Des各程序,
可能没真正理解这些程序,所以我想调用都不知道将这些东西
组合起来,有知道的请帮帮忙?。?
解析:
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 *** yzePath(){
String dirName;
int pos=srcFileNamestIndexOf("/");
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=destFileNamestIndexOf("/");
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()+(byteLeft8 ? (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; i4; i++) {
outBuf.putChar(destStr.charAt(i));
}
outBuf.flip();
}else{
outBuf.position(0);
outBuf.limit(2*destStr.length());
for (int i = 0; idestStr.length(); i++) {
outBuf.putChar(destStr.charAt(i));
}
outBuf.flip();
}

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