Android文件加密解密的实现

最近项目中需要用到加解密功能，言外之意就是不想让人家在反编译后通过不走心就能获取文件里一些看似有用的信息

/** Automatically generated file. DO NOT MODIFY */
package com.example.testcipher;

public final class BuildConfig {
    public final static boolean DEBUG = true;
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件        475  2017-04-13 14:52  TestCipher\.classpath

     文件        846  2017-04-13 14:52  TestCipher\.project

     文件        177  2017-04-13 14:52  TestCipher\.settings\org.eclipse.jdt.core.prefs

     文件       1045  2017-04-13 14:53  TestCipher\AndroidManifest.xml

     文件       1045  2017-12-08 08:50  TestCipher\bin\AndroidManifest.xml

     文件        353  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\BuildConfig.class

     文件       3515  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\CipherUtil.class

     文件        285  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\CustomFileCipherUtil$CipherListener.class

     文件       4051  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\CustomFileCipherUtil.class

     文件       1123  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$1.class

     文件       1786  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$2$1$1.class

     文件       2054  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$2$1.class

     文件       1121  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$2.class

     文件       1786  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$3$1$1.class

     文件       2054  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$3$1.class

     文件       1121  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity$3.class

     文件       2133  2017-12-08 08:50  TestCipher\bin\classes\com\example\testcipher\MainActivity.class

     文件        352  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$attr.class

     文件        473  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$dimen.class

     文件        419  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$drawable.class

     文件        576  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$id.class

     文件        415  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$layout.class

     文件        400  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$menu.class

     文件        484  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$string.class

     文件        443  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R$style.class

     文件        713  2017-12-15 09:31  TestCipher\bin\classes\com\example\testcipher\R.class

     文件        120  2017-12-15 09:31  TestCipher\bin\jarlist.cache

     文件        164  2017-12-08 08:50  TestCipher\gen\com\example\testcipher\BuildConfig.java

     文件       2778  2017-12-15 09:31  TestCipher\gen\com\example\testcipher\R.java

     文件      51394  2017-04-13 14:52  TestCipher\ic_launcher-web.png

............此处省略53个文件信息