Ant 之 生成 ant.dtd 文件 (轉載)

Is there a DTD that I can use to validate my build files?

An incomplete DTD can be created by the <antstructure> task - but this one has a few problems:

• It doesn't know about required attributes. Only manual tweaking of this file can help here.
• It is not complete - if you add new tasks via <taskdef> it won't know about it. See this page by Michel Casabianca for a solution to this problem. Note that the DTD you can download at this page is based on Ant 0.3.1.
• It may even be an invalid DTD. As Ant allows tasks writers to define arbitrary elements, name collisions will happen quite frequently - if your version of Ant contains the optional <test> and <junit> tasks, there are two XML elements named test (the task and the nested child element of <junit>) with different attribute lists. This problem cannot be solved; DTDs don't give a syntax rich enough to support this.

雖然dtd會限制ant的可擴展性可是在語法提示的誘惑下仍是生成了這個DTD；

方法大體以下：

1.創建一個build.xml

2.輸入內容：

<?xml version="1.0" encoding="UTF-8"?>
       <project>
              <target name="makedtd">
                   <antstructure output="project.dtd" />
              </target>
       </project>

3.到build.xml所在目錄下執行ant_home%/bin/ant makedtd

4.BUILD FAILED!發生一個NoClassDefFoundError錯誤,大體是說org/apache/commons/net/ftp/FTPClientConfig沒找到

可是project.dtd仍是生成了，我這裏這個ANT1.7生成的115KB。

5.爲了解決這個問題首先查得FTPClientConfig是apache的commons-net包的，因而下載http://apache.mirror.phpchina.com/commons/net/binaries/commons-net-1.4.1.zip，放到ant_home的lib目錄下 ，再次構建 OK ,沒有錯誤提示project.dtd生成202KB。

不過好像給XMLSpy掛上仍是沒有語法提示 -_-

6.仔細看了一下原來生成的DTD裏邊有幾處問題。

   1）第六行<!ELEMENT project (target | %tasks; | %types;)*>

   此行末尾的‘*’號應該爲‘+’號由於每一個build.xml都應該起碼有一個<project>元素

   2）根據XMLSpy提示，有個定義<!ELEMENT targe EMPTY>。

   3) 根據XMLSpy提示<!ELEMENT FTP.........>這塊也有問題，因爲平時基本不會用到所以刪掉。

OK 如今已是個良好格式(well-formet)的project.dtd文件了。

如今經過XMLSpy根據此project.dtd 創建的build.xml就具有了通常的語法提示功能了。