文件AES加密、解密

对文件加密、解密。支持各种格式的文件

先看效果

**可以看到加密之后内容为一串类似于乱码之类的
解密之后又恢复为原内容**

直接上代码：

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;
import java.util.Arrays;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
/**
 * @author ZSL
 * @since 2016年12月7日上午10:18:27
 * @desc [文件加密]
 */
public class AESFileUtil {

    private static final String key = "password";

    /** 
     * init AES Cipher
     * @param passsword
     * @param cipherMode 
     * @return 
     */
    public static Cipher initAESCipher(String passsword, int cipherMode) {
        Cipher cipher = null;
        try {
            SecretKey key = getKey(passsword);
            cipher = Cipher.getInstance("AES/ECB/PKCS7Padding");
            cipher.init(cipherMode, key);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        } catch (InvalidKeyException e) {
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
        }
        return cipher;
    }

    private static SecretKey getKey(String password) {
        int keyLength = 256;
        byte[] keyBytes = new byte[keyLength / 8];
        SecretKeySpec key = null;
        try {
            Arrays.fill(keyBytes, (byte) 0x0);
            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
            byte[] passwordBytes = password.getBytes("UTF-8");
            int length = passwordBytes.length < keyBytes.length ? passwordBytes.length : keyBytes.length;
            System.arraycopy(passwordBytes, 0, keyBytes, 0, length);

            key = new SecretKeySpec(keyBytes, "AES");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return key;
    }


    /**
     * AES 加密
     * @param encryptPath
     * @param decryptPath
     * @param sKey
     * @return
     */
    public static boolean encryptFile(String encryptPath, String decryptPath, String sKey){
        File encryptFile = null;
        File decryptfile = null;
        CipherOutputStream cipherOutputStream = null;
        BufferedInputStream bufferedInputStream = null;
        try {
            encryptFile = new File(encryptPath);
            if(!encryptFile.exists()) {
                throw  new NullPointerException("Encrypt file is empty");
            }
            decryptfile = new File(decryptPath);
            if(decryptfile.exists()) {
                decryptfile.delete();
            }
            decryptfile.createNewFile();

            Cipher cipher = initAESCipher(sKey, Cipher.ENCRYPT_MODE);
            cipherOutputStream = new CipherOutputStream(new FileOutputStream(decryptfile), cipher);
            bufferedInputStream = new BufferedInputStream(new FileInputStream(encryptFile));

            byte[] buffer = new byte[1024];
            int bufferLength;

            while ((bufferLength = bufferedInputStream.read(buffer)) != -1) {
                cipherOutputStream.write(buffer, 0, bufferLength);
            }
            bufferedInputStream.close();
            cipherOutputStream.close();
//            delFile(encryptPath);
        }  catch (IOException e) {
            delFile(decryptfile.getAbsolutePath());
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            return false;
        }
        return true;
    }

    /**
     * AES 解密
     * @param encryptPath
     * @param decryptPath
     * @param mKey
     * @return
     */

    public static boolean decryptFile(String encryptPath, String decryptPath, String mKey){
        File encryptFile = null;
        File decryptFile = null;
        BufferedOutputStream outputStream = null;
        CipherInputStream inputStream = null;
        try {
            encryptFile = new File(encryptPath);
            if(!encryptFile.exists()) {
                throw new NullPointerException("Decrypt file is empty");
            }
            decryptFile = new File(decryptPath);
            if(decryptFile.exists()) {
                decryptFile.delete();
            }
            decryptFile.createNewFile();

            Cipher cipher = initAESCipher(mKey, Cipher.DECRYPT_MODE);

            outputStream = new BufferedOutputStream(new FileOutputStream(decryptFile));
            inputStream = new CipherInputStream(new FileInputStream(encryptFile), cipher);

            int bufferLength;
            byte[] buffer = new byte[1024];

            while ((bufferLength = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bufferLength);
            }
            inputStream.close();
            outputStream.close();
//            delFile(encryptPath);
        } catch (IOException e) {
            delFile(decryptFile.getAbsolutePath());
            e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
            return false;
        }
        return true;
    }


    /**
     * delete File
     * @param pathFile
     * @return
     */
    public static boolean delFile(String pathFile) {
        boolean flag = false;
        if(pathFile == null && pathFile.length() <= 0) {
            throw new NullPointerException("文件不能为空");
        }else {
            File file = new File(pathFile);
            // 路径为文件且不为空则进行删除
            if (file.isFile() && file.exists()) {
                file.delete();
                flag = true;
            }
        }
        return flag;
    }


    public static void main(String[] args) {
        boolean flag = AESFileUtil.encryptFile
                ("E:/pdf/html/原文件.txt", "E:/pdf/html/加密后.txt", key);
        System.out.println(flag);
        flag = AESFileUtil.decryptFile
                ( "E:/pdf/html/加密后.txt","E:/pdf/html/解密后.txt", key);
        System.out.println(flag);
    }


}

注意：如果出现以下问题

原因： Oracle在其官方网站上提供了无政策限制权限文件（Unlimited Strength Jurisdiction Policy Files），我们只需要将其部署在JRE环境中，就可以解决限制问题。

解决办法：

jdk6无政策限制权限文件下载
jdk7无政策限制权限文件下载
jdk8无政策限制权限文件下载

把下载好的文件解压出来，放到 java\jdk\jre\lib\security下
一个文件是：local_policy.jar
另一个是：US_export_policy.jar
OK！