在系统源码中添加一个APK源码目录，并写了相应的android.mk文件，编译时出错如下：
make: *** No rule to make target `out/target/common/obj/JAVA_LIBRARIES/liba71S_intermediates/javalib.jar‘, needed by `out/target/common/obj/APPS/My_Settings_intermediates/classes-full-debug.jar‘. Stop.
make: *** Waiting for unfinished jobs....
按之前的经验，尝试了几种方法，发现都没有解决，后来定位到android.mk文件写的有问题
修改前：
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_JAVA_LIBRARIES := bouncycastle telephony-common
LOCAL_STATIC_JAVA_LIBRARIES := android-support-v4 testinterface
LOCAL_MODULE_TAGS := optional
LOCAL_SRC_FILES := $(call all-java-files-under, src)
LOCAL_PACKAGE_NAME := My_Settings
LOCAL_CERTIFICATE := platform
LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES :android-support-v4:libs/android-support-v4.jar testinterface:libs/testinterface.jar
include $(BUILD_PACKAGE)
# Use the folloing include to make our test apk.
include $(call all-makefiles-under,$(LOCAL_PATH))
上述编译会出错，
修改后，编译ｏＫ
LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)
LOCAL_JAVA_LIBRARIES := bouncycastle telephony-common
LOCAL_STATIC_JAVA_LIBRARIES := android-support-v4 testinterface
LOCAL_MODULE_TAGS := optional
LOCAL_SRC_FILES := $(call all-java-files-under, src)
LOCAL_PACKAGE_NAME := My_Settings
LOCAL_CERTIFICATE := platform
include $(BUILD_PACKAGE)
include $(CLEAR_VARS)
LOCAL_PREBUILT_STATIC_JAVA_LIBRARIES :android-support-v4:libs/android-support-v4.jar testinterface:libs/testinterface.jar
include $(BUILD_MULTI_PREBUILT)
# Use the folloing include to make our test apk.
include $(call all-makefiles-under,$(LOCAL_PATH))
其他说明：
1.要使用ｍｍ命令单独编译某个模块或者应用，首先需要在JB目录下全部编译一次。
如果断开编译服务器（如关机后第二天再次需要单独编译）后，想再次单独编译，只需要配置项目环境，当然前提是你之前编译过一次，并且没有clean过。配置项目编译环境命令：1. source build/envsetup.sh 2. lunch project_number
2.如果你的模块或者应用的android.mk里面配置LOCAL_MODULE_TAGS := optional ，则需要把LOCAL_PACKAGE_NAME 对应的名字添加到系统的PRODUCT_PACKAGES +=中，如PRODUCT_PACKAGES +=My_Setting \
3.其他具体编译错误，再根据具体的log信息处理
原文：http://blog.csdn.net/andrewblog/article/details/18597433