The earlier protobuf version 3.0 was easily integrated. But there are issues with the latest version 3.2. It simply compiles & builds all the un-related Android .cc file components as well.
If we follow the path to latest branch in git for c++ proto & build it as per the steps, then it generates 15 MB .SO file, unlike earlier which was ~1-2 MB.
How to optimally integrate latest protobuf to Android?
Using cross platform Android Standalone Tool chain and provided build script may result in larger size of Shared library file(.so), generated due to unwanted files included in build script.You can create your own Android.mk file which includes only required core part of the library. Generated library files can be used as pre built library in other Android projects. Please check bellow steps for second option of creating own script files.
jni inside application project../autogen.sh
./configure
jni directory.jni directory.Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
c_includes := $(LOCAL_PATH)
LOCAL_MODULE := libprotobuf
LOCAL_SRC_FILES := \
google/protobuf/arena.cc \
google/protobuf/arenastring.cc \
google/protobuf/extension_set.cc \
google/protobuf/generated_message_util.cc \
google/protobuf/io/coded_stream.cc \
google/protobuf/io/zero_copy_stream.cc \
google/protobuf/io/zero_copy_stream_impl_lite.cc \
google/protobuf/message_lite.cc \
google/protobuf/repeated_field.cc \
google/protobuf/stubs/atomicops_internals_x86_gcc.cc \
google/protobuf/stubs/atomicops_internals_x86_msvc.cc \
google/protobuf/stubs/bytestream.cc \
google/protobuf/stubs/common.cc \
google/protobuf/stubs/int128.cc \
google/protobuf/stubs/once.cc \
google/protobuf/stubs/status.cc \
google/protobuf/stubs/statusor.cc \
google/protobuf/stubs/stringpiece.cc \
google/protobuf/stubs/stringprintf.cc \
google/protobuf/stubs/structurally_valid.cc \
google/protobuf/stubs/strutil.cc \
google/protobuf/stubs/time.cc \
google/protobuf/wire_format_lite.cc \
google/protobuf/any.cc \
google/protobuf/any.pb.cc \
google/protobuf/api.pb.cc \
google/protobuf/compiler/importer.cc \
google/protobuf/compiler/parser.cc \
google/protobuf/descriptor.cc \
google/protobuf/descriptor.pb.cc \
google/protobuf/descriptor_database.cc \
google/protobuf/duration.pb.cc \
google/protobuf/dynamic_message.cc \
google/protobuf/empty.pb.cc \
google/protobuf/extension_set_heavy.cc \
google/protobuf/field_mask.pb.cc \
google/protobuf/generated_message_reflection.cc \
google/protobuf/io/gzip_stream.cc \
google/protobuf/io/printer.cc \
google/protobuf/io/strtod.cc \
google/protobuf/io/tokenizer.cc \
google/protobuf/io/zero_copy_stream_impl.cc \
google/protobuf/map_field.cc \
google/protobuf/message.cc \
google/protobuf/reflection_ops.cc \
google/protobuf/service.cc \
google/protobuf/source_context.pb.cc \
google/protobuf/struct.pb.cc \
google/protobuf/stubs/mathlimits.cc \
google/protobuf/stubs/substitute.cc \
google/protobuf/text_format.cc \
google/protobuf/timestamp.pb.cc \
google/protobuf/type.pb.cc \
google/protobuf/unknown_field_set.cc \
google/protobuf/util/field_comparator.cc \
google/protobuf/util/field_mask_util.cc \
google/protobuf/util/internal/datapiece.cc \
google/protobuf/util/internal/default_value_objectwriter.cc \
google/protobuf/util/internal/error_listener.cc \
google/protobuf/util/internal/field_mask_utility.cc \
google/protobuf/util/internal/json_escaping.cc \
google/protobuf/util/internal/json_objectwriter.cc \
google/protobuf/util/internal/json_stream_parser.cc \
google/protobuf/util/internal/object_writer.cc \
google/protobuf/util/internal/proto_writer.cc \
google/protobuf/util/internal/protostream_objectsource.cc \
google/protobuf/util/internal/protostream_objectwriter.cc \
google/protobuf/util/internal/type_info.cc \
google/protobuf/util/internal/type_info_test_helper.cc \
google/protobuf/util/internal/utility.cc \
google/protobuf/util/json_util.cc \
google/protobuf/util/message_differencer.cc \
google/protobuf/util/time_util.cc \
google/protobuf/util/type_resolver_util.cc \
google/protobuf/wire_format.cc \
google/protobuf/wrappers.pb.cc \
google/protobuf/compiler/code_generator.cc \
google/protobuf/compiler/command_line_interface.cc \
google/protobuf/compiler/cpp/cpp_enum.cc \
google/protobuf/compiler/cpp/cpp_enum_field.cc \
google/protobuf/compiler/cpp/cpp_extension.cc \
google/protobuf/compiler/cpp/cpp_field.cc \
google/protobuf/compiler/cpp/cpp_file.cc \
google/protobuf/compiler/cpp/cpp_generator.cc \
google/protobuf/compiler/cpp/cpp_helpers.cc \
google/protobuf/compiler/cpp/cpp_map_field.cc \
google/protobuf/compiler/cpp/cpp_message.cc \
google/protobuf/compiler/cpp/cpp_message_field.cc \
google/protobuf/compiler/cpp/cpp_primitive_field.cc \
google/protobuf/compiler/cpp/cpp_service.cc \
google/protobuf/compiler/cpp/cpp_string_field.cc \
google/protobuf/compiler/plugin.cc \
google/protobuf/compiler/plugin.pb.cc \
google/protobuf/compiler/python/python_generator.cc \
google/protobuf/compiler/ruby/ruby_generator.cc \
google/protobuf/compiler/subprocess.cc \
google/protobuf/compiler/zip_writer.cc \
LOCAL_CFLAGS := -D GOOGLE_PROTOBUF_NO_RTTI=1
LOCAL_CPPFLAGS := -std=c++11
LOCAL_C_INCLUDES = $(LOCAL_PATH)/android
LOCAL_C_INCLUDES += ${ANDROID_NDK}/sources/cxx-stl/gnu- libstdc++/4.8/include
LOCAL_LDLIBS += -lz
LOCAL_EXPORT_LDLIBS += -lz
LOCAL_EXPORT_CFLAGS := $(LOCAL_CFLAGS)
LOCAL_EXPORT_CPPFLAGS := $(LOCAL_CPPFLAGS)
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
include $(BUILD_SHARED_LIBRARY)
Application.mk
APP_STL :=gnustl_shared # gnustl_static
NDK_TOOLCHAIN_VERSION := 4.9
APP_ABI := all
LIBCXX_FORCE_REBUILD := true
APP_PLATFORM:=android-9
NDK_DEBUG:=1
ndk-build and required .so files will be generated inside libs folder of the project directory.