1，Tomcat6 源文件目录树结构
目录结构如下图：
目录：
/bin 存放脚本文件，包括启动tomcat以及关闭tomcat等功能的bat，sh脚本。
/conf 存放tomcat的xml配置文件和properties配置文件。
/java java源代码放置到这个目录。
/native tomcat的native-connector工程放置的目录，是一个vc60工程。
/res ini文件及其它的一些静态资源文件可以放在res目录，以及生成可执行文件的nsis脚本。
/test 放置测试文件，项目
/webapps 放置tomcat的web工程文件
文件：
/build.properties.default 构建工程的属性文件
/build.xml ant 构建文件
/dist.xml 生成目标的构建文件
/extras.xml 扩展的构建文件
/其他 其他为说明文件
2，如何构建Tomcat6
(0)下载安装jdk1.5或者以上版本，设置JAVA_HOME环境变量指向JDK的安装目录。如果已经安装jdk，跳转到步骤1。
(1)安装apache ant 1.6.x。如果已经安装，请跳转到步骤2.下载apache
http://ant.apache.org/bindownload.cgi 。安装。
*创建ANT_HOME 环境变量，指向ant的安装目录 ${ant.home}.
* 在系统PATH环境变量中添加${ant.home}/bin .
(2)构建 Tomcat 6.0
(2.1)获取 Tomcat 6.0的源代码
* Tomcat SVN repository URL:
http://svn.apache.org/repos/asf/tomcat/tc6.0.x/
* Download a source package from:
http://tomcat.apache.org/download-60.cgi
* Checkout the source using SVN, selecting the desired version or
branch (current development source is at
http://svn.apache.org/repos/asf/tomcat/tc6.0.x/trunk/), or
unpack the source package. The location where the source has been
placed will be referred as ${tomcat.source}.
(2.2) 构建
* Go to that directory, and do:
cd ${tomcat.source}
ant download
ant
* NOTE: Users accessing the Internet through a proxy must use a properties
file to indicate to Ant the proxy configuration. Read below.
* WARNING: Running this command will download binaries to the /usr/share/java
directory. Make sure this is appropriate to do on your computer. On Windows,
this usually corresponds to the "C:/usr/share/java" directory, unless Cygwin
is used. Read below to customize the directory used to download the binaries.
* The build can be controlled by creating a ${tomcat.source}/build.properties
file, and adding the following content to it:
# ----- Proxy setup -----
# Uncomment if using a proxy server
#proxy.host=proxy.domain
#proxy.port=8080
#proxy.use=on
# ----- Default Base Path for Dependent Packages -----
# Replace this path with the directory path where dependencies binaries
# should be downloaded
base.path=/usr/share/java
(3) Updating sources
It is recommended that you regularly update the downloaded Tomcat 6 sources
using your SVN client.
(4) Rebuilds
For a quick rebuild of only modified code you can use:
cd ${tomcat.source}
ant
(5) Building the servlet and jsp API documentation
The documentation can be easly built:
cd ${tomcat.source}
ant -f dist.xml dist-javadoc
(6) Building the extras (commons-logging, webservices etc.).
cd ${tomcat.source}
ant -f extras.xml
(7) Building a release running tests:
cd ${tomcat.source}
ant -f dist.xml release
3，build.xml解析
Build.xml是一个标准的ant的构建文件，通过此文件，可以构建tomcat工程。大纲结构如下：
分析：
1,Tomcat工程的默认目标是deploy。
2,在工程的开头，首先指定构建文件的属性文件和属性。属性文件为build.properties.
3, download目标作用为下载tomcat编译依赖的库文件等。它依赖于如下几个目标。
setproxy，proxyflags目标任务是设置网络代理,testexit,downloadgz,downloadzip, downloadfile这几个目标共同完成下载依赖文件的任务。Build-tomcat-dbcp,build-jasper-jdt作用是编译下载的依赖文件。
4,deploy目标作用生成/output/classes，和/output/build目录，编译java源代码生成class文件存放到classes目录，部署tomcat在build目录。