Android Memory optimization tips and tricks

Android central process Zygote forked to allocate memory for every other process. Because of limited resource in mobile, memory optimization is necessary in android. Don't ask for more memory if you don't require it. Here are some tips which will help running your application smoothly

• Enums often require more than twice as much memory as static constants. You should strictly avoid using enums on Android.

• Every class in Java (including anonymous inner classes) uses about 500 bytes of code.  and every class instance has 12-16 bytes of RAM overhead.

• Putting a single entry into a HashMap requires the allocation of an additional entry object that takes 32 bytes 

• Use optimized container from android framework like  SparseArray, SparseBooleanArray, and LongSparseArray. generic HashMap use can be quite memory inefficient because it needs a separate entry object for every mapping so use  SparseArray.

• Release memory as memory becomes tight 

• onTrimMemory() callback of Activity help you finding way to release resource. Callbacks like TRIM_MEMORY_RUNNING_LOW, TRIM_MEMORY_RUNNING_MODERATE, TRIM_MEMORY_RUNNING_CRITICAL etc gives you way to release unused resource which eventually help improving performance of your app

• Load views on demand using ViewStub read about ViewStub

• Use multiple process in a single application. Name your background services as separate process like 

         <service android:name=".PlaybackService" android:process=":background" />