How to copy the eclipse Android Application project into android source code and compile it ???

 copy the application project into android source code's packages/apps/ folder
within the application project,Add Android.mk with below contents:

 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 LOCAL_MODULE_TAGS := optional
 LOCAL_SRC_FILES := $(call all-subdir-java-files)
 LOCAL_PACKAGE_NAME := VolumeControl_S #Target package name
 include $(BUILD_PACKAGE)

 From android folder give source build/envsetup.sh,lunch and then
 cd to packages/apps/yourApplication/ and give mm command. This will build the application code & create the APK file.