Ant JavaDoc 任务从自定义 taglet 中抛出 `NoClassDefFoundError`，即使类 *is* 在类路径上答案

【问题标题】：Ant JavaDoc task throwing `NoClassDefFoundError` from within a custom taglet, even though the class *is* on the classpathAnt JavaDoc 任务从自定义 taglet 中抛出 `NoClassDefFoundError`，即使类 *is* 在类路径上
【发布时间】：2015-01-24 02:44:03
【问题描述】：

我在处理 JavaDoc Ant 任务时遇到问题。它给了我一个java.lang.NoClassDefFoundError 一个类，据我所知，它肯定在类路径上。根据the documentation，当类在编译期间存在时抛出NoClassDefFoundError，但在运行时找不到。（一个NoClassDefFoundError is not a ClassNotFoundException。）

当我删除类路径项时，它会按预期失败（大量未找到包/符号错误）并且它仍然给出相同的NoClassDefFoundError。为什么无论类是否在类路径上，taglet 都会失败？

具体情况：

找不到的类叫com.github.xbn.io.SimpleDebugable，在这个jar文件里：

Jar 文件：C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\z_build\jar_dependencies\xbnjava-0.1.4.2-all.jar

JavaDoc Ant 任务。上面的 jar 文件是类路径中的第一项。

<target name="doca" description="Generates javadoc documentation.">
   <property name="jar_base_dir" value="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\z_build\jar_dependencies\"/>
   <property name="taglet_jar" value="C:\data_jeffy\programming\build\codelet-0.1.4.1\download\codelet-0.1.4.1-all.jar"/>

   <javadoc
      packagenames="com.github.aliteralmind.codelet,com.github.aliteralmind.codelet.alter,com.github.aliteralmind.codelet.simplesig,com.github.aliteralmind.codelet.taglet,com.github.aliteralmind.codelet.type,com.github.aliteralmind.codelet.util"
      defaultexcludes="yes"
      destdir="C:\data_jeffy\programming\build\codelet-0.1.4.1\documentation\javadoc"
      splitindex="true"
      additionalparam="-J-Dcodelet_config_dir=C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\codelet_config\"
      classpath="${jar_base_dir}xbnjava-0.1.4.2-all.jar;
      C:\data_jeffy\programming\build\codelet-0.1.4.1\download\codelet-0.1.4.1-all.jar;
      ${jar_base_dir}templatefeather-0.1.1.2-all.jar;
      ${jar_base_dir}commons-io-2.4.jar;
      ${jar_base_dir}guava-16.0.1.jar;
      ${jar_base_dir}jdk_751__tools__contains_com_sun.jar"
   >
      <sourcepath>
          <pathelement path="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src"/>
      </sourcepath>
      <!-- Custom taglets-->
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletTaglet"
            path="${taglet_jar}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletDotOutTaglet"
            path="${taglet_jar}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletAndOutTaglet"
            path="${taglet_jar}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.FileTextletTaglet"
            path="${taglet_jar}"/>
   </javadoc>
</target>

结果如下：

[javadoc] javadoc: error - In doclet class com.sun.tools.doclets.standard.Standard,
method start has thrown an exception java.lang.reflect.InvocationTargetException
[javadoc] java.lang.NoClassDefFoundError: com/github/xbn/io/SimpleDebuggable

完整输出：

[C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet]ant docx
Buildfile: C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\build.xml

docx:
  [javadoc] Generating Javadoc
  [javadoc] Javadoc execution
  [javadoc] Loading source files for package com.github.aliteralmind.codelet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.alter...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.simplesig...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.taglet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.type...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.util...
  [javadoc] Constructing Javadoc information...
  [javadoc] 1 error
  [javadoc] javadoc: error - In doclet class com.sun.tools.doclets.standard.Standard, method start has thrown an exception java.lang.reflect.InvocationTargetException
  [javadoc] java.lang.NoClassDefFoundError: com/github/xbn/io/SimpleDebuggable
  [javadoc]     at java.lang.ClassLoader.defineClass1(Native Method)
  [javadoc]     at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  [javadoc]     at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  [javadoc]     at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  [javadoc]     at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [javadoc]     at java.security.AccessController.doPrivileged(Native Method)
  [javadoc]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.wasLoaded(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.loadConfiguration(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.<clinit>(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.taglet.CodeletTaglet.<clinit>(Unknown Source)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  [javadoc]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [javadoc]     at java.lang.reflect.Method.invoke(Method.java:606)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.taglets.TagletManager.addCustomTag(TagletManager.java:219)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.initTagletManager(Configuration.java:466)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.setOptions(Configuration.java:437)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.setOptions(Configuration.java:447)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:120)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.start(AbstractDoclet.java:83)
  [javadoc]     at com.sun.tools.doclets.formats.html.HtmlDoclet.start(HtmlDoclet.java:63)
  [javadoc]     at com.sun.tools.doclets.standard.Standard.start(Standard.java:39)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  [javadoc]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [javadoc]     at java.lang.reflect.Method.invoke(Method.java:606)
  [javadoc]     at com.sun.tools.javadoc.DocletInvoker.invoke(DocletInvoker.java:280)
  [javadoc]     at com.sun.tools.javadoc.DocletInvoker.start(DocletInvoker.java:160)
  [javadoc]     at com.sun.tools.javadoc.Start.parseAndExecute(Start.java:397)
  [javadoc]     at com.sun.tools.javadoc.Start.begin(Start.java:167)
  [javadoc]     at com.sun.tools.javadoc.Main.execute(Main.java:59)
  [javadoc]     at com.sun.tools.javadoc.Main.main(Main.java:49)
  [javadoc] Caused by: java.lang.ClassNotFoundException: com.github.xbn.io.SimpleDebuggable
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [javadoc]     at java.security.AccessController.doPrivileged(Native Method)
  [javadoc]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  [javadoc]     ... 37 more

BUILD SUCCESSFUL
Total time: 1 second

当您从类路径中完全删除 jar 文件时，它会按预期失败，出现数百个 package com.github.xbn.... does not exist 和 symbol not found 错误，这意味着类路径元素显然是“工作”。那么为什么它对 taglet 不起作用？

类路径上带有 not jar 的输出：

[C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet]ant docx
Buildfile: C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\build.xml

docx:
  [javadoc] Generating Javadoc
  [javadoc] Javadoc execution
  [javadoc] Loading source files for package com.github.aliteralmind.codelet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.alter...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.simplesig...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.taglet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.type...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.util...
  [javadoc] Constructing Javadoc information...
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:18: error: package com.github.xbn.linefilter.alter does not exist

  [javadoc]     import  com.github.xbn.linefilter.alter.TextLineAlterer;
  [javadoc]                                            ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:19: error: package com.github.xbn.linefilter does not exist
  [javadoc]     import  com.github.xbn.linefilter.FilteredLineIterator;
  [javadoc]                                      ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:20: error: package com.github.xbn.analyze.alter does not exist
  [javadoc]     import  com.github.xbn.analyze.alter.ExpirableElements;
  [javadoc]                                         ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:21: error: package com.github.xbn.analyze.alter does not exist
  [javadoc]     import  com.github.xbn.analyze.alter.MultiAlterType;
  [javadoc]                                         ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:22: error: package com.github.xbn.array does not exist
  [javadoc]     import  com.github.xbn.array.NullElement;
  [javadoc]                                 ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:23: error: package com.github.xbn.lang does not exist
  [javadoc]     import  com.github.xbn.lang.IllegalArgumentStateException;
  [javadoc]                                ^

续（删除了约 1,500 行）：

  [javadoc]     import  com.github.xbn.linefilter.FilteredLineIterator;
  [javadoc]                                      ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\util\zCodeletCustomizers.java:25: error: package com.github.xbn.analyze.alter does notexist
  [javadoc]     import  com.github.xbn.analyze.alter.ExpirableElements;
  [javadoc]                                         ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\util\zCodeletCustomizers.java:26: error: package com.github.xbn.analyze.alter does notexist
  [javadoc]     import  com.github.xbn.analyze.alter.MultiAlterType;
  [javadoc]                                         ^
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\util\zCodeletCustomizers.java:27: error: package com.github.xbn.array does not exist
  [javadoc] 1 error
  [javadoc]     import  com.github.xbn.array.NullElement;
  [javadoc] 371 warnings
  [javadoc]                                 ^

继续：在最后，它给出了与 jar 在类路径中时相同的错误：

  [javadoc] javadoc: error - In doclet class com.sun.tools.doclets.standard.Standard,
  method start has thrown an exception java.lang.reflect.InvocationTargetException
  [javadoc] java.lang.NoClassDefFoundError: com/github/xbn/io/SimpleDebuggable
  [javadoc]     at java.lang.ClassLoader.defineClass1(Native Method)
  [javadoc]     at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
  [javadoc]     at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
  [javadoc]     at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
  [javadoc]     at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [javadoc]     at java.security.AccessController.doPrivileged(Native Method)
  [javadoc]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.wasLoaded(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.loadConfiguration(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.CodeletBootstrap.<clinit>(Unknown Source)
  [javadoc]     at com.github.aliteralmind.codelet.taglet.CodeletTaglet.<clinit>(Unknown Source)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  [javadoc]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [javadoc]     at java.lang.reflect.Method.invoke(Method.java:606)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.taglets.TagletManager.addCustomTag(TagletManager.java:219)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.initTagletManager(Configuration.java:466)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.setOptions(Configuration.java:437)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.Configuration.setOptions(Configuration.java:447)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:120)
  [javadoc]     at com.sun.tools.doclets.internal.toolkit.AbstractDoclet.start(AbstractDoclet.java:83)
  [javadoc]     at com.sun.tools.doclets.formats.html.HtmlDoclet.start(HtmlDoclet.java:63)
  [javadoc]     at com.sun.tools.doclets.standard.Standard.start(Standard.java:39)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  [javadoc]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  [javadoc]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [javadoc]     at java.lang.reflect.Method.invoke(Method.java:606)
  [javadoc]     at com.sun.tools.javadoc.DocletInvoker.invoke(DocletInvoker.java:280)
  [javadoc]     at com.sun.tools.javadoc.DocletInvoker.start(DocletInvoker.java:160)
  [javadoc]     at com.sun.tools.javadoc.Start.parseAndExecute(Start.java:397)
  [javadoc]     at com.sun.tools.javadoc.Start.begin(Start.java:167)
  [javadoc]     at com.sun.tools.javadoc.Main.execute(Main.java:59)
  [javadoc]     at com.sun.tools.javadoc.Main.main(Main.java:49)
  [javadoc] Caused by: java.lang.ClassNotFoundException: com.github.xbn.io.SimpleDebuggable
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
  [javadoc]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
  [javadoc]     at java.security.AccessController.doPrivileged(Native Method)
  [javadoc]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
  [javadoc]     at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
  [javadoc]     ... 37 more

BUILD SUCCESSFUL
Total time: 1 second

在原始（上图）目标中，taglet 的路径指向 jar 文件。下面，我将taglet类文件从jar中解压到一个目录中（只提取了这四个taglet类，其他的都保留在jar中），并将taglet路径更改为根目录。

<property name="jar_base_dir" value="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\z_build\jar_dependencies\"/>
<property name="taglet_base_dir" value="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\bin\com\github\aliteralmind\codelet\taglet"/>
  <javadoc
  packagenames="com.github.aliteralmind.codelet,com.github.aliteralmind.codelet.alter,com.github.aliteralmind.codelet.simplesig,com.github.aliteralmind.codelet.taglet,com.github.aliteralmind.codelet.type,com.github.aliteralmind.codelet.util"
  defaultexcludes="yes"
  destdir="C:\data_jeffy\programming\build\codelet-0.1.4.1\documentation\javadoc"
  splitindex="true"
  additionalparam="-J-Dcodelet_config_dir=${dir_sandbox}${codelet.config.dir}${fs}"
  classpath="${jar_base_dir}xbnjava-0.1.4.2-all.jar;
  C:\data_jeffy\programming\build\codelet-0.1.4.1\download\codelet-0.1.4.1-all.jar;
  ${jar_base_dir}templatefeather-0.1.1.2-all.jar;
  ${jar_base_dir}commons-io-2.4.jar;
  ${jar_base_dir}guava-16.0.1.jar;
  ${jar_base_dir}jdk_751__tools__contains_com_sun.jar"
>
  <sourcepath>
    <pathelement path="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src"/>
  </sourcepath>
  <!-- Custom taglets-->
    <taglet name="com.github.aliteralmind.codelet.taglet.CodeletTaglet"
      path="${taglet_base_dir}"/>
    <taglet name="com.github.aliteralmind.codelet.taglet.CodeletDotOutTaglet"
      path="${taglet_base_dir}"/>
    <taglet name="com.github.aliteralmind.codelet.taglet.CodeletAndOutTaglet"
      path="${taglet_base_dir}"/>
    <taglet name="com.github.aliteralmind.codelet.taglet.FileTextletTaglet"
      path="${taglet_base_dir}"/>
</javadoc>

现在NoClassDefFoundError 不会发生。而是

javadoc: error - Error - Exception java.lang.ClassNotFoundException
thrown while trying to register Taglet com.github.aliteralmind.codelet.taglet.CodeletTaglet...

现在的问题是，这个错误似乎被 JavaDoc “吞噬”了。不知道怎么看那个java.lang.ClassNotFoundException的踪迹。

完整输出：

docb:
  [javadoc] Generating Javadoc
  [javadoc] Javadoc execution
  [javadoc] Loading source files for package com.github.aliteralmind.codelet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.alter...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.simplesig...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.taglet...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.type...
  [javadoc] Loading source files for package com.github.aliteralmind.codelet.util...
  [javadoc] Constructing Javadoc information...
  [javadoc] javadoc: error - Error - Exception java.lang.ClassNotFoundException
  thrown while trying to register Taglet com.github.aliteralmind.codelet.taglet.CodeletTaglet...
  [javadoc] javadoc: error - Error - Exception java.lang.ClassNotFoundException
  thrown while trying to register Taglet com.github.aliteralmind.codelet.taglet.CodeletDotOutTaglet...
  [javadoc] javadoc: error - Error - Exception java.lang.ClassNotFoundException
  thrown while trying to register Taglet com.github.aliteralmind.codelet.taglet.CodeletAndOutTaglet...
  [javadoc] Standard Doclet version 1.7.0_72
  [javadoc] javadoc: error - Error - Exception java.lang.ClassNotFoundException thrown while trying to register Taglet com.github.aliteralmind.codelet.taglet.FileTextletTaglet...
  [javadoc] Building tree for all the packages and classes...
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\BasicCustomizers.java:90:
  warning - @.codelet is an unknown tag.

  ...lots of lines deleted...

  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\util\JavaDocUtil.java:185:
  warning - @.codelet.and.out is an unknown tag.
  [javadoc] C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src\com\github\aliteralmind\codelet\util\JavaDocUtil.java:185:
  warning - @.codelet.and.out is an unknown tag.
  [javadoc] Building index for all the packages and classes...
  [javadoc] Building index for all classes...
  [javadoc] Generating C:\data_jeffy\programming\build\codelet-0.1.4.1\documentation\javadoc\help-doc.html...
  [javadoc] 4 errors
  [javadoc] 57 warnings

BUILD SUCCESSFUL
Total time: 2 seconds

还有详细的输出：http://dpaste.com/3T0B40X

【问题讨论】：

您自己构建了这个特殊的 Jar 吗？这个类文件是否可能已损坏或编译为不同的（较新的）java版本？尝试干净构建 jar。
@geert3 代码在每次调用 javadoc 目标之前立即编译和 jar-ed。我不知道这是否重要，但这里有两个 Ant 环境变量：ANT_HOME=C:\applications\programming\java\apache-ant-1.9.4、JAVA_HOME=C:\applications\programming\java\jdk_1p7p0_72。

标签： java ant classpath javadoc taglet

【解决方案1】：

问题在于 taglet 路径。类路径必须冗余地传递到主 JavaDoc 任务和每个自定义 taglet。每个小标签必须有不同的ClassLoaders，因此需要重复的类路径。

蚂蚁documentation for the taglet's "path" attribute 没有明确说这是一个类路径，这让我很困惑：

指定 taglet 类的搜索路径的路径（例如 /home/taglets）。路径也可以由嵌套元素指定

工作目标：

<target name="docc" description="Generates javadoc documentation.">

   <property name="jar_base_dir" value="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\z_build\jar_dependencies\"/>
   <property name="taglet_base_dir" value="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\bin\"/>
   <property name="javadoc_classpath"
      value="${jar_base_dir}xbnjava-0.1.4.2-all.jar;C:\data_jeffy\programming\build\codelet-0.1.4.1\download\codelet-0.1.4.1-all.jar;${jar_base_dir}templatefeather-0.1.1.2-all.jar;${jar_base_dir}commons-io-2.4.jar;${jar_base_dir}guava-16.0.1.jar;${jar_base_dir}jdk_751__tools__contains_com_sun.jar;${jar_base_dir}commons-lang3-3.3.2.jar"/>

   <javadoc
      packagenames="com.github.aliteralmind.codelet,com.github.aliteralmind.codelet.alter,com.github.aliteralmind.codelet.simplesig,com.github.aliteralmind.codelet.taglet,com.github.aliteralmind.codelet.type,com.github.aliteralmind.codelet.util"
      defaultexcludes="yes"
      destdir="C:\data_jeffy\programming\build\codelet-0.1.4.1\documentation\javadoc"
      splitindex="true"
      additionalparam="-J-Dcodelet_config_dir=${dir_sandbox}${codelet.config.dir}${fs}"
      classpath="${javadoc_classpath}"
   >
      <sourcepath>
         <pathelement path="C:\data_jeffy\programming\sandbox\z__for_git_commit_only\codelet\src"/>
      </sourcepath>
      <!-- Custom taglets-->
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletDotOutTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletAndOutTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.FileTextletTaglet"
            path="${javadoc_classpath}"/>
   </javadoc>
</target>

更便携的替代方案：

<target name="docd" description="Generates javadoc documentation.">
   <property name="sandbox_grandparent" value="C:/data_jeffy/programming/"/>
   <property name="sandbox_parent" value="${sandbox_grandparent}sandbox/z__for_git_commit_only/"/>
   <property name="sandbox" value="${sandbox_parent}codelet/"/>

   <path id="project_classpath2">
      <pathelement location="${sandbox_parent}codelet/bin/"/>
      <pathelement location="${sandbox_grandparent}/build/codelet-0.1.4.1/download/codelet-0.1.4.1-all.jar"/>
      <fileset dir="${sandbox}z_build/jar_dependencies/" includes="*.jar"/>
   </path>
   <pathconvert pathsep=";" property="javadoc_classpath" refid="project_classpath2"/>

   <javadoc
      packagenames="com.github.aliteralmind.codelet.*"
      defaultexcludes="yes"
      destdir="${sandbox_grandparent}/build/codelet-0.1.4.1/documentation/javadoc"
      splitindex="true"
      additionalparam="-J-Dcodelet_config_dir=${dir_sandbox}${codelet.config.dir}${fs}"
      classpathref="project_classpath2"
   >
      <sourcepath>
         <pathelement path="${sandbox}src"/>
      </sourcepath>
      <!-- Custom taglets-->
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletDotOutTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.CodeletAndOutTaglet"
            path="${javadoc_classpath}"/>
         <taglet name="com.github.aliteralmind.codelet.taglet.FileTextletTaglet"
            path="${javadoc_classpath}"/>
   </javadoc>
</target>

【讨论】：