android /java base64（DES）加密json数据，并保存到json文件
导出调用
private void ExpData(){
try {
List> list = initData();
String json = JSONArray.toJSONString(list);
String str = encrypt("加密秘钥不少于8位",json);
writeJson(mContext,str,
"aaa.json",false);
} catch (Exception e) {
e.printStackTrace();
}
}
写入json文件方法
/**
* 存储Json文件
*
* @param context
* @param json
* json字符串
* @param fileName
* 存储的文件名
* @param append
* true 增加到文件末，false则覆盖掉原来的文件
*/
private static void writeJson(Context context, String json, String fileName,
boolean append) {
File CacheRoot = Environment.getExternalStorageDirectory(); //sd卡根路径
try {
verifyStoragePermissions((Activity)context); //读写sd卡权限
File ff = new File(CacheRoot, fileName);
OutputStream out = new FileOutputStream(ff);
out.write(json.getBytes());
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
private static final int REQUEST_EXTERNAL_STORAGE = 1;
private static String[] PERMISSIONS_STORAGE = {
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE };
public static void verifyStoragePermissions(Activity activity) {
// Check if we have write permission
int permission = ActivityCompat.checkSelfPermission(activity,
Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (permission != PackageManager.PERMISSION_GRANTED) {
// We don't have permission so prompt the user
ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE,
REQUEST_EXTERNAL_STORAGE);
}
}
base64（des）加密方法（java、android通用）
import com.alibaba.fastjson.JSONArray;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.security.Key;
import java.util.Calendar;
import java.util.List;
import java.util.Map;
import android.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.IvParameterSpec;
/**
* 偏移变量，固定占8位字节
*/
private final static String IV_PARAMETER = "12345678";
/**
* 密钥算法
*/
private static final String ALGORITHM = "DES";
/**
* 加密/解密算法-工作模式-填充模式
*/
private static final String CIPHER_ALGORITHM = "DES/CBC/PKCS5Padding";
/**
* 默认编码
*/
private static final String CHARSET = "utf-8";
/**
* DES加密字符串
*
* @param password 加密密码，长度不能够小于8位
* @param data 待加密字符串
* @return 加密后内容
*/
public static String encrypt(String password, String data) {
if (password== null || password.length() < 8) {
throw new RuntimeException("加密失败，key不能小于8位");
}
if (data == null)
return null;
try {
Key secretKey = generateKey(password);
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
IvParameterSpec iv = new IvParameterSpec(IV_PARAMETER.getBytes(CHARSET));
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
byte[] bytes = cipher.doFinal(data.getBytes(CHARSET));
return android.util.Base64.encodeToString(bytes, Base64.DEFAULT);//Android平台可以使用android.util.Base64
//return new String(Base64.getEncoder().encode(bytes));//JDK1.8及以上可直接使用Base64，JDK1.7及以下可以使用BASE64Encoder
} catch (Exception e) {
e.printStackTrace();
return data;
}
}
/**
* DES解密字符串
*
* @param password 解密密码，长度不能够小于8位
* @param data 待解密字符串
* @return 解密后内容
*/
public static String decrypt(String password, String data) {
if (password== null || password.length() < 8) {
throw new RuntimeException("加密失败，key不能小于8位");
}
if (data == null)
return null;
try {
Key secretKey = generateKey(password);
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
IvParameterSpec iv = new IvParameterSpec(IV_PARAMETER.getBytes(CHARSET));
cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
return new String(cipher.doFinal(Base64.getDecoder().decode(data.getBytes(CHARSET))), CHARSET);
/*
如果报错：java.lang.IllegalArgumentException: Illegal base64 character a
可改为
return new String(cipher.doFinal(Base64.getMimeDecoder().decode(data.getBytes(CHARSET))), CHARSET);
*/
} catch (Exception e) {
e.printStackTrace();
return data;
}
}
/**
* 生成key
*
* @param password
* @return
* @throws Exception
*/
private static Key generateKey(String password) throws Exception {
DESKeySpec dks = new DESKeySpec(password.getBytes(CHARSET));
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(ALGORITHM);
return keyFactory.generateSecret(dks);
}
/**
* DES加密文件
*
* @param srcFile 待加密的文件
* @param destFile 加密后存放的文件路径
* @return 加密后的文件路径
*/
public static String encryptFile(String password, String srcFile, String destFile) {
if (password== null || password.length() < 8) {
throw new RuntimeException("加密失败，key不能小于8位");
}
try {
IvParameterSpec iv = new IvParameterSpec(IV_PARAMETER.getBytes(CHARSET));
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
cipher.init(Cipher.ENCRYPT_MODE, generateKey(key), iv);
InputStream is = new FileInputStream(srcFile);
OutputStream out = new FileOutputStream(destFile);
CipherInputStream cis = new CipherInputStream(is, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = cis.read(buffer)) > 0) {
out.write(buffer, 0, r);
}
cis.close();
is.close();
out.close();
return destFile;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
/**
* DES解密文件
*
* @param srcFile 已加密的文件
* @param destFile 解密后存放的文件路径
* @return 解密后的文件路径
*/
public static String decryptFile(String password, String srcFile, String destFile) {
if (password== null || password.length() < 8) {
throw new RuntimeException("加密失败，key不能小于8位");
}
try {
File file = new File(destFile);
if (!file.exists()) {
file.getParentFile().mkdirs();
file.createNewFile();
}
IvParameterSpec iv = new IvParameterSpec(IV_PARAMETER.getBytes(CHARSET));
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
cipher.init(Cipher.DECRYPT_MODE, generateKey(key), iv);
InputStream is = new FileInputStream(srcFile);
OutputStream out = new FileOutputStream(destFile);
CipherOutputStream cos = new CipherOutputStream(out, cipher);
byte[] buffer = new byte[1024];
int r;
while ((r = is.read(buffer)) >= 0) {
cos.write(buffer, 0, r);
}
cos.close();
is.close();
out.close();
return destFile;
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}