Android中手机文件储存路径

/**
     * Android的存储结构
     *
     *  1.内部存储(非内存):
     *  /data {@link Environment#getDataDirectory()}
     *      /data
     *          /package name
     *              /files      {@link Context#getFilesDir()}
     *              /cache      {@link Context#getCacheDir()}
     *              /customize  {@link Context#getDir(String, int)} // {@link Context#MODE_PRIVATE}
     *              ...
     *  2.外部存储:
     *  2.1 机身
     *  /sdcard {@link Environment#getExternalStorageDirectory()} //注意不同的版本打印可能显示不同的名字(但是指向同一个目录)
     *      /Android
     *          /data
     *              /package name
     *                  /files
     *                      /customize  {@link Context#getExternalFilesDir(String)}
     *                  /cache          {@link Context#getExternalCacheDir()}
     *      /other {@link Environment#getExternalStoragePublicDirectory(String)}
     *
     *
     *  2.2 SD卡
     *  {@link Context#getExternalCacheDirs()} 遍历得到
     *
     *  tips:
     *      判断外部存储是否可用:
     *      {@link Environment#getExternalStorageState()} == {@link Environment#MEDIA_MOUNTED}
     */