util.java

使用vc++编码 很好的加密算法 有较强的保密功能

package com.crypto.encrypt;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ResourceBundle;
import java.util.Locale;

public class Util {

  /**
   * 资源读取类
   */
  private static ResourceBundle resources=null;
  /**
   * 初始化资源
   */
  static {
        new Util();
    }


  public Util() {
    resources = ResourceBundle.getBundle(
          "resource.algorithm",
          Locale.getDefault());

  }
  /**
   * 读取源文件内容
   * @param filename String 文件路径
   * @throws IOException
   * @return byte[] 文件内容
   */
  public static byte[] readFile(String filename) throws IOException {

    File file =new File(filename);
    if(filename==null || filename.equals(""))
    {
      throw new NullPointerException("无效的文件路径");
    }
    long len = file.length();
    byte[] bytes = new byte[(int)len];

    BufferedInputStream bufferedInputStream=new BufferedInputStream(new FileInputStream(file));
    int r = bufferedInputStream.read( bytes );
    if (r != len)
      throw new IOException("读取文件不正确");
    bufferedInputStream.close();

    return bytes;

  }

  /**
   * 将加密的数据写入文件
   * @param data byte[]
   * @throws IOException
   */
  public static void writeFile(byte[] data,String filename) throws IOException {
    File file =new File(filename);
    file.getParentFile().mkdirs();
    BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(new FileOutputStream(file));
    bufferedOutputStream.write(data);
    bufferedOutputStream.close();

  }

  /**
   * 从jar文件里读取class
   * @param filename String
   * @throws IOException
   * @return byte[]
   */
  public byte[] readFileJar(String filename) throws IOException {
    BufferedInputStream bufferedInputStream=new BufferedInputStream(getClass().getResource(filename).openStream());
    int len=bufferedInputStream.available();
    byte[] bytes=new byte[len];
    int r=bufferedInputStream.read(bytes);
    if(len!=r)
    {
      bytes=null;
      throw new IOException("读取文件不正确");
    }
    bufferedInputStream.close();
    return bytes;
  }

  /**
   * 获得密码生成法则
   * @return String
   */
  public static String getAlgorithm()
  {
      return resources.getString("algorithm");
  }
  /**
   * 获得值
   * @param skey String
   * @return String
   */
  public static String getValue(String skey)
  {
    return resources.getString(skey);
  }
}