jsp新代码第225课

new225.java

package pack03;

import java.security.Key;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.SecureRandom;
import java.util.Base64;
import java.util.Base64.Decoder;
import java.util.Base64.Encoder;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;


public class new225
{
  Key key1;
  
  public new225()
  {
    
  }
  
  public new225(String str)
  {
    setKey(str);
  }
  
  public Key getKey()
  {
    return key1;
  }
  
  public void setKey(Key key)
  {
    this.key1 = key;
  }
  
  public void setKey(String str)
  {
    try
    {
      KeyGenerator _geGenerator = KeyGenerator.getInstance("DES");
      _geGenerator.init(new SecureRandom(str.getBytes()));
      this.key1 = _geGenerator.generateKey();
      _geGenerator = null;
      
    } 
    catch (Exception e)
    {
      throw new RuntimeException("Error initalizing sqlmap class cause:" + e);
    }
  }
  
  public String encryptStr(String strMing)
  {
    byte[] byteMi = null;
    byte[] byteMing = null;
    String strMi = "";
    
    Encoder encoder = Base64.getEncoder();
    
    try
    {
      byteMing = strMing.getBytes("utf8");
      byteMi = this.encryptByte(byteMing);
      strMi = encoder.encodeToString(byteMi);
    } 
    catch (Exception e)
    {
      throw new RuntimeException("Error initializing sqlmap class cause" + e);
    }
    finally
    {
      encoder = null;
      byteMing = null;
      byteMi = null;
    }
    
    return strMi;
  }

  private byte[] encryptByte(byte[] byteMing)
  {
    byte[] byteFina = null;
    Cipher cipher;
    try
    {
      cipher = Cipher.getInstance("DES");
      cipher.init(Cipher.ENCRYPT_MODE, key1);
      byteFina = cipher.doFinal(byteMing);
    } 
    catch (Exception e)
    {
      throw new RuntimeException("Error initializing sqlmap class cause" + e);
    }
    finally
    {
      cipher = null;
    }
    return byteFina;
  }
  
  public String decryptStr(String strMi)
  {
    Decoder decoder = Base64.getDecoder();
    
    byte[] byteMing = null;
    byte[] byteMi = null;
    String strMing = "";
    
    try
    {
      byteMi = decoder.decode(strMi);
      byteMing = this.decryptByte(byteMi);
      strMing = new String(byteMing,"utf8");
      
    } 
    catch (Exception e)
    {
      throw new RuntimeException("Error initializing sqlmap class cause:" + e);
    }
    finally
    {
      decoder = null;
      byteMing = null;
      byteMi = null;
    }
    
    return strMing;
  }

  private byte[] decryptByte(byte[] byteMi)
  {
    Cipher cipher;
    byte[] byteFina = null;
    try
    {
      cipher = Cipher.getInstance("DES");
      cipher.init(Cipher.DECRYPT_MODE, key1);
      byteFina = cipher.doFinal(byteMi);

    }
    catch (Exception e)
    {
      throw new RuntimeException("Error initializing sqlmap class cause:" + e);
    }
    finally
    {
      cipher = null;
      
    }
    return byteFina;
  }
  
  public void encryptFile(String file,String destFile) throws Exception
  {
    Cipher cipher = Cipher.getInstance("DES");
    cipher.init(Cipher.ENCRYPT_MODE, this.key1);
    InputStream is = new FileInputStream(file);
    OutputStream out = new FileOutputStream(destFile);
    CipherInputStream cis = new CipherInputStream(is, cipher);
    
    byte[] buffer = new byte[1024];
    int r = 0;
    while ((r = cis.read(buffer)) > 0)
    {
      out.write(buffer,0,r);
    }
    cis.close();
    is.close();
    out.close();
  }
  
  public void decryptFile(String file,String destFile) throws Exception
  {
    Cipher cipher = Cipher.getInstance("DES");
    cipher.init(Cipher.DECRYPT_MODE, this.key1);
    InputStream is = new FileInputStream(file);
    OutputStream out = new FileOutputStream(destFile);
    CipherOutputStream cos = new CipherOutputStream(out, cipher);
    
    byte[] buffer = new byte[1024];
    int r = -1;
    while ((r = is.read(buffer)) >= 0)
    {
      cos.write(buffer,0,r);
    }
    cos.close();
    out.close();
    is.close();
  }
}