android - Permissions for getExternalCacheDir() and getCacheDir() -

my http library caching http responses. current implementation select directory cache data looks this:

public static file getdiskcachedir(context c) {         file dir = c.getexternalcachedir();          if (dir == null)             dir = c.getcachedir();          return dir;     } 

the idea use getexternalcachedir() first option because assume there more space available getcachedir(). official docs states free space in getcachedir() shouldn't large (1 mb?)

you should have reasonable maximum, such 1 mb, amount of space consume cache files, , prune files when exceeding space.

my maximum space 40 mb.

so have 2 questions:

1. should use getexternalcachedir()? apps minsdk = 14. or should use getcachedir()?

2. if should use getexternalcachedir() permissions required? according official documentation:

starting in kitkat, no permissions required read or write returned path; it's accessible calling app. applies paths generated package name of calling application. access paths belonging other packages, write_external_storage and/or read_external_storage required.

so understanding write_external_storage (includes permission read, @ least prior api 19) required work getexternalcachedir() prior kitkat (api 19).

so permission have set is:

<uses-permission android:name="android.permission.write_external_storage" android:maxsdkversion="19"/> 

right? see related bugs on lollipop this: why need write_external_storage permission getexternalcachedir() on android lollipop?

should add try-catch block around getexternalcachedir() , use getcachedir() fallback?