Android开发实践：用脚本编译Android工程

   一般情况下，我们都是使用Eclipse+ADT插件或者Android studio软件来编译Android工程的，其实，Eclipse或者Android studio仅仅是将一些编译命令封装到可视化界面里而已，通过shell脚本、ADT附带的一些命令以及Ant工具，我们完全可以将Android工程的编译过程自动化，直接通过运行脚本就得到最终的APK文件。

   Linux下用脚本编译c/c++程序至少需要两个东西，一个是编译器，如gcc/g++，另一个则是编译配置文件，即Makefile；同理，编译Android程序也同样需要编译器和编译配置文件，由于Android程序是Java开发的，所以编译器一般使用Ant（Apache的核心项目，Java编译器），配置文件则是build.xml，该编译配置文件可以自己手写，也可以通过ADT的工具生成；如果Andrid工程涉及JNI层，则编译命令使用NDK-Build，对应的编译配置文件则是Android.mk。

   前面这段话，简单介绍了使用脚本编译Andriod工程的一些基本工具和关键词，详细的用法就留给读者自己去Google吧，这里给出一个我自己编写的通用脚本，放到你的Android工程的根目录，修改脚本的相关路径的配置，添加执行权限(chmod +x)，即可编译你的Android工程了，具体的用法用注释的形式添加在脚本中了，文章最后的附件则是该脚本的测试Android工程。

#!/bin/bash
                                                                                                                                                                                                                                                            
#NOTE: 用法，在本工程根目录下执行 ./build.sh xxx
                                                                                                                                                                                                                                        
#其中，xxx为参数，可以是clean debug release，也可以不带参数，不带参数默认为debug
                                                                                                                                                                                                                                           
#如果参数是 clean，  则会删除所有编译生成的文件              
#如果参数是 debug ， 则会生成 debug 版本的apk,位于 bin 目录下
#如果参数是 release，则生成 release版本的apk，位于 bin 目录下
                                                                                                                                                                                                                                            
#NOTE: 如果更改了工程配置，请先删除目录下的build.xml
                                                                                                                                                                                                                                           
#获取本目录的名称，作为build.xml的项目名称
PROJECT_NAME=${PWD##*/}
                                                                                                                                                                                                                                                  
#路径配置，请根据编译环境修改
ANDROID_SDK_PATH=/opt/android/sdk
ANDROID_NDK_PATH=/opt/android/ndk
ANT_PATH=/opt/apache-ant-1.9.0/bin
                                                                                                                                                                                                                                                            
#决定是否生成release版
BUILD_RELEASE=0
                                                                                                                                                                                                                                                             
if [ $1 = "clean" ]
then
    rm -rf gen
    rm -rf obj
    rm -rf libs/armeabi
    echo "clean success"
    exit
fi
                                                                                                                                                                                                                                                
if [ $1 = "debug" ]
then
    BUILD_RELEASE=0
fi
                                                                                                                                                                                                                                                     
if [ $1 = "release" ]
then
    BUILD_RELEASE=1
fi
                                                                                                                                                                                                                                                                        
echo "begin to build..."
                                                                                                                                                                                                                                                            
#判断 build.xml 是否存在，若不存在，则创建一个
#请根据你的目标平台，修改update project命令的最后一个参数，该值为 android list 命令输出结果列表的id值
                                                                                                                                                                                                                                                       
if [ ! -e build.xml ]
then
    echo "No build.xml exist, generate build.xml"
    $SDK_PATH/tools/android update project -n $PROJECT_NAME -p . -s -t 1
fi
                                                                                                                                                                                                                                                                 
#判断jni目录是否存在，如果存在，则首先编译jni目录
if [ -d jni ]
then
    echo "build jni, generate libs"
    $ANDROID_NDK_PATH/ndk-build
fi
                                                                                                                                                                                                                                                              
#使用ant来编译
if [ $BUILD_RELEASE ]
then
    $ANT_PATH/ant release 
else
    $ANT_PATH/ant debug
fi
echo "build success"

   在Android工程的根目录运行该脚本文件后，会在bin目录下生成apk文件，如果工程目录下没有ant.properties文件和xxx.key文件的话，则只会生成debug版和unsigned-release版，如果希望直接生成签名后的apk文件，则需要给出一个Android key文件，并编写一个ant.properties文件，该文件的编写示例如下：

key.store=ticktick.key
key.alias=ticktick
key.store.password=123456
key.alias.password=123456

   在Android工程的根目录下，如果存在该ant.properties文件，则在编译release版的时候，会自动使用ticktick.key文件来签名生成的apk文件。

   关于使用脚本编译Android工程就介绍到这儿了，希望我的示例脚本能够给初学者提供一些参考和帮助，有任何疑问欢迎留言或者来信lujun.hust@gmail.com交流，或者关注我的新浪微博 @卢_俊 获取最新的文章和资讯。