I use this proguard file:
-dontskipnonpubliclibraryclasses -dontskipnonpubliclibraryclassmembers !code/simplification/arithmetic,!code/simplification/cas
Add following lines in your proguard file.
-keep class org.apache.http.** { *; } -keep class org.apache.** { *; } -dontwarn org.apache.** -dontwarn org.apache.http.** -dontwarn org.apache.commons.**