Apache Ant编写build.xml的自动提示 ANT DTD

大家都知道Eclipse的自动输入或者自动完成的功能是用XML的DTD文件来控制的，但是安装了ANT的插件之后会发现Apache并没有为我们直接提供书写build.xml的DTD文件，可能是由于扩张方面的考虑。在Apache的 FAQ里有提到

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 Apache 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.

原文在这里（http://ant.apache.org/faq.html#dtd）

但是Ant的预订标签里面提供了生成DTD的方法。这里需要在%ANT_HOME%的lib目录下面加一个JAR包，

下载地址http://apache.mirror.phpchina.com/commons/net/binaries/commons-net-1.4.1.zip

现在新建一个build.xml

内容如下

<?xml version="1.0" encoding="UTF-8"?>

<project>
　　<target name="makeantdtd">
　　　　<antstructure output="ant_DTD.dtd" />
　　</target>
</project>

然后使用ANT命令执行这个build.xml文件，在相同路径下就会生成ant_DTD.dtd

现在用Eclipse引用这个DTD就可以实现编写build.xml的时候的自动提示了。

建议把这放在%ANT_HOME%的 etc目录下，以免误删。

Eclipse的设置在：Window--Preference--XML--XML Catalog 点击Add 输入刚才那个生成的DTD文件地址，KEY_TYPE选 public ID , 取一个名字（KEY）,OK

现在按下alt+/ 就可以在有提示内容的地方弹出提示了

当然，如果想在输入的时候就直接弹出，要设置：Window--Preference--XML--XML File--Editor 在Content asist里，勾上 Automatically make suggestion, 然后在

Prompt when these characters are inserted 里面改成 <=:abcdefghijklmnopqrstuvwxyz ${

OK！当然这样做会是Eclipse的速度变慢，喜忧参半。

 

仅供参考学习交流。