Ant 项目构建(1)
为了条理地介绍Ant，下面我分几部分来介绍Ant：
1.什么是Ant
Ant是一种基于java的build工具，理论上来说，有点类似与（liunx）种的make，但是修复了make的缺陷，使build更加好用，更加方便。
这里有必要介绍一下为什么会产生Ant这个工具？
既然已经有了make，gnumake，nmake，jam和其他的构建工具，为什么还有开发另外一个呢？这时因为那些工具都具有局限性，Ant的原作者（JamesDuncanDavidson）在开发跨平台软件时，并不能使用其中一个完成所有的任务，这就好像，在英语不是通用语言之前，你去那里，必须搞个翻译似的，降低了开发小绿绿，也急不利于大型软件开发的维护。已有的构建工具都是基于特定平台和听顶语言的，受到操作系统的限制太大。
更重要的是，makefile有天生的痼疾，任何在liunx下调试过C程序的都碰到过可恶的Tab问题。也许一个多余的空格，就会导致一个build不能运行？你说？这方便吗？
而Ant则在所有构建工具的基于上，开发出来了跨平台，跨语言的构建工具，已成为最优秀的构建工具，几乎所有的IDE都自带了Ant工具。
2. Ant的特点
- 跨平台性，ant是基于java的，而java跨平台的性能是与庸置疑的，ant配置文件是基于XML的，而XML是格式最规范的数据格式。因而Ant跨平台的性能也不言而喻
- 功能强大，从项目的编译，打包，发布，测试到版本的控制，Ant无所不能
- 灵活方便
- 可重用性高， Ant的配置文件Build.xml以一个project为开头，以不同的target为任务模块，彼此之间相互独立，但是模块之间又可以相互联系，因而耦合性和内聚性达到了完美的统一
- 开源软件
[xml]
<project name="encrypt" default="help" basedir=".">
<!–
All properties should be defined in this section.Any host-specific properties should be defined
in the build.properties file.
In this app,the following properties are defined in build.properties:
1.tomcat.home === the home directory of your Tomcat installation
2.webapps.home === the place to copy the war file to deploy it.
–>
<property file="build.properties"/>
<property name="app.home" value="."/>
<property name="app.name" value="application"/>
<property name="javadoc.pkg.top" value="encrypt"/>
<property name="src.home" value="${app.home}/src"/>
<property name="lib.home" value="${app.home}/lib"/>
<property name="classes.home" value="${app.home}/classes"/>
<property name="deploy.home" value="${app.home}/deploy"/>
<property name="doc.home" value="${app.home}/doc"/>
<property name="web.home" value="${app.home}/WebRoot"/>
<property name="build.home" value="${app.home}/build"/>
<property name="build.classes" value="${build.home}/WEB-INF/classes"/>
<property name="build.lib" value="${build.home}/WEB-INF/lib"/>
<!–Compilatin Classpath–>
<!– This section creates the classpath for compilation–>
<path id="compile.classpath">
<!–The lib files for this application–>
<fileset dir="${lib.home}">
<include name="*.jar"/>
<include name="*.zip"/>
</fileset>
<!–All files/jars that Tomcat makes available–>
<fileset dir="${tomcat.home}/common/lib">
<include name="*.jar"/>
</fileset>
<pathelement location="${tomcat.home}/common/classes"/>
</path>
<!–==========help targe==========–>
<!–This is the default ant target executed if no target is specified.
This helps avoid user just typed ‘ant’ and runing a default target
that may not do what they are anticipating
–>
<target name="help">
<echo message="Please specify a target![usage:ant <targetname>]"/>
<echo message="Here is a list of possible targets:"/>
<echo message=" clean-all …..Delete all dir,all.class and war files"/>
<echo message=" prepare …..Create directories if required"/>
<echo message=" compile …..Compiles source file"/>
<echo message=" build …..Build war file form.class and other files"/>
<echo message=" deploy …..Copy war files to the webapps directory"/>
<echo message=" javadoc …..Generates javadoc for this application"/>
</target>
<!–=========="clean-all" target==========–>
<target name="clean">
<delete dir="${build.home}"/>
<delete dir="${classes.home}"/>
<delete dir="${deploy.home}"/>
<!–cannot delete directory if tomcat is runing–>
<delete dir="${webapps.home}/${app.home}" failonerror="false"/>
<delete dir="${webapps.home}/S{app.name}.war"/>
<!–delete javadoc–>
<delete dir="${doc.home}"/>
</target>
<!—==========="prepare" target===========–>
<!– This target is executed prior to any of the later targets
to make sure the directories exist.It only creates them if
they need to be created…
Other,similar,preparation steps can be placed here
–>
<target name="prepare">
<echo message="Tomcat Home =${tomcat.home}"/>
<echo message = "webapps Home = ${webapps.home}"/>
<mkdir dir="${classes.home}"/>
<mkdir dir="${deploy.home}"/>
<mkdir dir="${doc.home}"/>
<mkdir dir="${doc.home}/api"/>
<mkdir dir="${build.home}"/>
<mkdir dir="${build.home}/WEB-INF"/>
<mkdir dir="${build.home}/WEB-INF/classes"/>
<mkdir dir="${build.home}/WEB-INF/lib"/>
</target>
<!–=========="compile" target==========–>
<!–This only compiles java files that are newer
than their corresponing.class files
–>
<target name="compile" depends ="prepare">
<javac srcdir="${src.home}" destdir="${classes.home}" debug="yes">
<classpath refid = "compile.classpath"/>
</javac>
</target>
<!–============"build" target=============–>
<!–This target builds the war file for the application by
first building the directory structure of the application
in ${build.home} and then creating the war file using the
ant <war> task
–>
<target name="build" depends="compile">
<!–Copy all the wabapp content(jsp’s,html,tld’s,xml,etc…–>
<copy todir="${build.home}">
<fileset dir="${web.home}"/>
</copy>
<!–copy all java class files–>
<copy todir="${build.home}/WEB-INF/classes">
<fileset dir="${classes.home}"/>
</copy>
<!–Now, copy all the properties files,etc that go on the classpath–>
<copy todir="${build.home}/WEB-INF/classes">
<fileset dir="${src.home}">
<include name="**/*.properties"/>
<include name="**/*.prop"/>
</fileset>
</copy>
<!–Now,copy all the jar files we need–>
<copy todir="${build.home}/WEB-INF/lib">
<fileset dir="${lib.home}"/>
</copy>
<!–create the <war> file–>
<jar jarfile="${deploy.home}/${app.name}.war" basedir="${build.home}"/>
</target>
<!–================"deploy" target============–>
<!– This target simply copies the war file from the deploy
directory into the Tomcat webapps directory.
–>
<target name="deploy" depends="build">
<!–copy the contents of the build directory–>
<copy todir="${webapps.home}" file="${deploy.home}/${app.name}.war"/>
</target>
<!–================="doc" target=========–>
<!– This task create javadoc.It is dependent upon only the ‘compile’ target
it is not executed in a normal build.As a result,the target needs to
be run on its own.
–>
<target name="javadoc" depends="compile">
<javadoc sourcepath="${src.home}" destdir="${doc.home}/api"
packagenames="${javadoc.pkg.top}.*"/>
</target>
</project>
[/xml]
webapps.home=F:\\Java\\Tomcat 5.5\\webapps