android 如何使用jar替换java代码编译

##
LOCAL_SRC_FILES := 
ifdef LOCAL_IS_HOST_MODULE
  $(error $(LOCAL_PATH): Just for target java library)
endif
LOCAL_MODULE_SUFFIX := $(COMMON_JAVA_PACKAGE_SUFFIX)
LOCAL_MODULE_CLASS := JAVA_LIBRARIES
LOCAL_BUILT_MODULE_STEM := javalib.jar
intermediates.COMMON := $(call local-intermediates-dir,COMMON)
full_classes_jar := $(intermediates.COMMON)/classes.jar
common_javalib.jar := $(intermediates.COMMON)/$(LOCAL_BUILT_MODULE_STEM)
LOCAL_INTERMEDIATE_TARGETS += $(full_classes_jar) $(common_javalib.jar)
ifneq (true,$(WITH_DEXPREOPT))
  LOCAL_DEX_PREOPT :=
else
ifeq (,$(TARGET_BUILD_APPS))
ifndef LOCAL_DEX_PREOPT
LOCAL_DEX_PREOPT := true
endif
endif
endif
ifeq (false,$(LOCAL_DEX_PREOPT))
LOCAL_DEX_PREOPT :=
endif
include $(BUILD_SYSTEM)/base_rules.mk
$(cleantarget): PRIVATE_CLEAN_FILES += $(intermediates.COMMON)
$(full_classes_jar) : $(LOCAL_PATH)/classes.jar | $(ACP)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
$(common_javalib.jar) : $(LOCAL_PATH)/$(LOCAL_BUILT_MODULE_STEM) | $(full_classes_jar) $(ACP)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
ifdef LOCAL_DEX_PREOPT
dexpreopt_boot_jar_module := $(filter $(LOCAL_MODULE),$(DEXPREOPT_BOOT_JARS_MODULES))
ifneq ($(dexpreopt_boot_jar_module),)
dexpreopted_boot_jar := $(DEXPREOPT_BOOT_JAR_DIR_FULL_PATH)/$(dexpreopt_boot_jar_module)_nodex.jar
$(LOCAL_BUILT_MODULE) : $(dexpreopted_boot_jar) | $(ACP)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
dexpreopted_boot_odex := $(DEXPREOPT_BOOT_JAR_DIR_FULL_PATH)/$(dexpreopt_boot_jar_module).odex
built_odex := $(basename $(LOCAL_BUILT_MODULE)).odex
$(built_odex) : $(dexpreopted_boot_odex) | $(ACP)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
else
built_odex := $(basename $(LOCAL_BUILT_MODULE)).odex
$(built_odex): PRIVATE_MODULE := $(LOCAL_MODULE)
$(built_odex) : $(DEXPREOPT_BOOT_ODEXS)
$(built_odex) : $(common_javalib.jar) | $(DEXPREOPT) $(DEXOPT)
 @echo "Dexpreopt Jar: $(PRIVATE_MODULE) ($@)" #注意：这里必须以tab键开头
 $(hide) rm -f $@ #注意：这里必须以tab键开头
 @mkdir -p $(dir $@) #注意：这里必须以tab键开头
 $(call dexpreopt-one-file,$<,$@) #注意：这里必须以tab键开头
$(LOCAL_BUILT_MODULE) : $(common_javalib.jar) | $(ACP) $(AAPT)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
ifneq (nostripping,$(LOCAL_DEX_PREOPT))
 $(call dexpreopt-remove-classes.dex,$@) #注意：这里必须以tab键开头
endif
endif
else
$(LOCAL_BUILT_MODULE) : $(common_javalib.jar) | $(ACP)
 $(call copy-file-to-target) #注意：这里必须以tab键开头
endif
 
3. 在alps/build/core/config.mk里加入：
BUILD_JAVA_LIBRARY_PREBUILT:= $(BUILD_SYSTEM)/java_library_prebuilt.mk
 
4. 删除相应的java代码及相应的Android.mk，然后在当前文件夹创建新的Android.mk。并复制第1步备份的2仅仅文件到Android.mk旁边(注意。文件名称不能改动，否则无法识别!!!)，新的Android.mk编写例如以下：
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := services
LOCAL_MODULE_PATH := $(TARGET_OUT_JAVA_LIBRARIES)
include $(BUILD_JAVA_LIBRARY_PREBUILT)
 
5. 又一次完整的编译project(随意eng/user)，下载查看效果
 
6. 重要提示，因为第1步保存的classes.jar是没有经过proguard。流出去非常easy被反编译，请做自己proguard，但请不要把接口proguard，否则编译失败！