hibernate - 为什么在我的 build.xml 中尝试运行 hibernate 工具时出现错误 "Only antlib URIs can be located from the URI alone,not the URI"

Question

我正在尝试在 ant 构建中运行 hibernate 工具以从我的 JPA 注释生成 ddl。 Ant 死于 taskdef 标签。我试过使用 ant 1.7、1.6.5 和 1.6 都无济于事。我在 eclipse 和外面都试过。我试过在 hibernate-tools 路径中包含所有 hbn jar ，但没有。请注意，我的构建文件基于这篇文章:

Hibernate JPA to DDL command line tools

我在 Ubuntu 8 上运行带有 WTP 3.0.1 和 MyEclipse 7.1 的 eclipse 3.4。

构建.xml:

<project name="generateddl" default="generate-ddl">

<path id="hibernate-tools">
    <pathelement location="../libraries/hibernate-tools/hibernate-tools.jar" />
    <pathelement location="../libraries/hibernate-tools/bsh-2.0b1.jar" />
    <pathelement location="../libraries/hibernate-tools/freemarker.jar" />
    <pathelement location="../libraries/jtds/jtds-1.2.2.jar" />
    <pathelement location="../libraries/hibernate-tools/jtidy-r8-20060801.jar" />

</path>

<taskdef classname="org.hibernate.tool.ant.HibernateToolTask" classpathref="hibernate-tools"/>

<target name="generate-ddl" description="Export schema to DDL file"> 
<!-- compile model classes before running hibernatetool -->

    <!-- task definition; project.class.path contains all necessary libs 
    <taskdef name="hibernatetool" classname="org.hibernate.tool.ant.HibernateToolTask" classpathref="project.class.path" />
    -->

    <hibernatetool destdir="sql"> 

        <!-- check that directory exists -->
        <jpaconfiguration persistenceunit="default" />

        <classpath>

            <dirset dir="WebRoot/WEB-INF/classes">
                <include name="**/*"/>
            </dirset>
        </classpath>

        <hbm2ddl outputfilename="schemaexport.sql" format="true" export="false" drop="true" />
    </hibernatetool>
</target>

Error message (ant -v):

    Apache Ant version 1.7.0 compiled on December 13 2006
Buildfile: /home/joe/workspace/bento/ant-generate-ddl.xml
parsing buildfile /home/joe/workspace/bento/ant-generate-ddl.xml with URI = file:/home/joe/workspace/bento/ant-generate-ddl.xml
Project base dir set to: /home/joe/workspace/bento
[antlib:org.apache.tools.ant] Could not load definitions from resource org/apache/tools/ant/antlib.xml. It could not be found.

BUILD FAILED
/home/joe/workspace/bento/ant-generate-ddl.xml:12: Only antlib URIs can be located from the URI alone,not the URI 
    at org.apache.tools.ant.taskdefs.Definer.execute(Definer.java:216)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:105)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:357)
    at org.apache.tools.ant.helper.ProjectHelper2.parse(ProjectHelper2.java:140)
    at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.parseBuildFile(InternalAntRunner.java:191)
    at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:400)
    at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137)

Total time: 195 milliseconds

Answer 1

根据typedef task documentation (其中 taskdef task 是一种形式)如果您没有指定“文件或资源类型属性”，则需要 name 属性。

我不确定解决这个问题是否能解决您的问题，但如果您能将其从潜在原因中排除就更好了。