防止java反编译的一点想法

      为了企业的代码的安全，可以在打包之前将类文件加密之后，打包成相关的文件，在加载时，获取类文件信息，并解密加载到JVM中。

 关于实现的代码如下：

 

package com.easyway.space.commons.classloaders.security;

import static com.easyway.space.commons.classloaders.security.CommonSpaceConstant.SECURITY_KEY_FILE_LOCATION_KEY;
import static com.easyway.space.commons.classloaders.security.CommonSpaceConstant.SYSTEMCONFIG_FILE_LOCATION;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;


/**
 * 
 * 类安全加载工具类
 * @author longgangbai
 *
 */
public class ClassSecurityUtils { 
	
	public static  Logger logger=Logger.getLogger(ClassSecurityUtils.class); 
	public static String SECURITY_KEY_FILE_LOCATION;
	static{
		SECURITY_KEY_FILE_LOCATION =PropertiesUtils.getProperties(SYSTEMCONFIG_FILE_LOCATION).getProperty(SECURITY_KEY_FILE_LOCATION_KEY);
	}
	/**
	 * 将客户端的jar文件通过循环依次加密
	 * @param clazzPath  类文件路径
	 * @throws Exception
	 */
    public static void cryptClass(String clazzPath) throws Exception {
        //获取密钥信息
        FileInputStream fi = new FileInputStream(new File(SECURITY_KEY_FILE_LOCATION));
        byte rawKeyData[]=IOUtils.toByteArray(fi);
        //创建加密的对象
        SecureRandom sr = new SecureRandom();
        DESKeySpec dks = new DESKeySpec(rawKeyData);
        SecretKey key = SecretKeyFactory.getInstance("DES").generateSecret(dks);
        Cipher cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.ENCRYPT_MODE, key, sr);
        //获取class文件加密前的信息
        File clazzFile=new File(clazzPath);
        FileInputStream fi2 = new FileInputStream(clazzFile);
        byte data[] = IOUtils.toByteArray(fi2);
        //获取加密之后的信息并写入文件
        byte encryptedData[] = cipher.doFinal(data);
        FileOutputStream fo = new FileOutputStream(clazzFile);
        IOUtils.write(encryptedData, fo);
    }
	/**
	 * 
	 * 用于解析加密过的class文件的并加载到JVM中
	 * @param filepath   密钥文件的路径
	 * @param clazzPath  需要解密的classpath文件的路径
	 * @param clazzLoader  相应的类加载器
	 * @throws InvalidKeyException  
	 * @throws InvalidKeySpecException
	 * @throws NoSuchAlgorithmException
	 * @throws NoSuchPaddingException
	 * @throws IllegalBlockSizeException
	 * @throws BadPaddingException
	 * @throws ClassNotFoundException
	 */
	public static void decryptClass(String filepath,String clazzPath,CustomerClassLoader clazzLoader) throws InvalidKeyException, InvalidKeySpecException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, ClassNotFoundException{
          //获取密钥文件的信息
		  File file=new File(filepath);
		  //获取Class 文件的信息
		   File clazzFile=new File(clazzPath);
       if(file.exists()){
		try {
			   //获取密钥的信息
			   byte rawKeyData[] = FileUtils.readFileToByteArray(file);
			   //设置安全算法的密钥
			   SecureRandom sr = new SecureRandom();
	   		   DESKeySpec dks = new DESKeySpec(rawKeyData);
	   		   //采用DES加密的算法
	   		   SecretKey key = SecretKeyFactory.getInstance("DES").generateSecret(dks);
	   		   Cipher cipher = Cipher.getInstance("DES");
	   		   //初始化密钥对象
	   		   cipher.init(Cipher.DECRYPT_MODE, key, sr);
	   		   if(clazzFile.exists())
	   		   {
	   			   //获取加密之前的文件的信息
	   			  byte rawEncryptedClassData[] =  FileUtils.readFileToByteArray(clazzFile);
	   			  //解密加密文件的信息
	   			  byte decryptedClazzData[] = cipher.doFinal(rawEncryptedClassData);
	   			  //通过类加载器加载类到JVM中
	   			  String className=clazzFile.getName();
	   			  
	   			  clazzLoader.loadClass(decryptedClazzData, className);
	   		   }
		} catch (IOException e) {
			logger.error("解析加载文件"+clazzFile.getName(), e);
		}
       }
	}


}