NoClassDefFoundError 使用常春藤。罐子不添加到类路径

Posted 2023-03-24

【中文标题】NoClassDefFoundError 使用常春藤。罐子不添加到类路径

【英文标题】：NoClassDefFoundError using ivy. Jars not adding to classpath

【发布时间】：2013-05-28 23:16:33

【问题描述】：

似乎我从我的 maven 存储库中提取的 jar 没有被放入我的 java 类路径中。我认为常春藤缓存会处理这个问题？

每当我在 eclipse 中或在 eclipse 之外运行一个类时，我都会得到 NoClassDefFoundError。 它编译得很好，但在运行时不起作用。我的依赖 conf 设置为 runtime->default 所以我认为这会起作用。

以下是我使用的文件。我做错了吗？

ivy.xml

<?xml version="1.0" encoding="UTF-8"?>
<ivy-module version="2.0"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xmlns:m="http://ant.apache.org/ivy/maven"
            xsi:noNamespaceSchemaLocation="http://ant.apache.org/ivy/schemas/ivy.xsd">
    <info organisation="org_test" module="mod_test" />
    <configurations>
    <conf name="compile" description="Required to compile application" />
    <conf name="runtime" description="Additional run-time dependencies" extends="compile" />
    <conf name="test" description="Required for test only" extends="runtime" />
    </configurations>
    <publications>
        <artifact ext="jar" />
        <artifact ext="pom" />
    </publications>
    <dependencies>
        <dependency org="org.apache.solr" name="solr-core" rev="3.5.0" conf="runtime->default" />
        <dependency org="org.apache.solr" name="solr-solrj" rev="3.6.0" conf="runtime->default" />
    </dependencies>
</ivy-module>

ivysettings.xml

<?xml version="1.0" encoding="UTF-8"?>
<ivysettings>
    <settings defaultResolver="chained" />
    <property name="maven.pattern" value="[organisation]/[module]/[revision]/[module]-[revision](-[classifier]).[ext]" />
    <property name="public.repo.url" value="http://$repo.host:$repo.port/nexus/content/groups/public/" override="false" />
    <property name="repo.host" value="localhost" override="false" />
    <property name="repo.port" value="8081" override="false" />
    <property name="repo.path" value="nexus/content/repositories" override="false" />
    <property name="retrieve.resolver" value="chained" override="false" />
    <resolvers>
        <ibiblio name="public" m2compatible="true" root="$public.repo.url" />
        <chain name="chained" returnFirst="false">
            <resolver ref="public" />
        </chain>
    </resolvers>
</ivysettings>

common.xml

<project name="common" xmlns:ivy="antlib:org.apache.ivy.ant">

    <dirname property="ivy-support.build.dir" file="$ant.file.ivy-support" />
    <property name="ivy-support.lib.dir" location="$ivy-support.build.dir/ivy" />
    <property name="ivy.settings.filename" value="ivysettings.xml" />

    <property name="ivy.install.version" value="2.1.0-rc2" />
    <condition property="ivy.home" value="$env.IVY_HOME">
      <isset property="env.IVY_HOME" />
    </condition>
    <property name="ivy.home" value="$user.home/.ant" />
    <property name="ivy.jar.dir" value="$ivy.home/lib" />
    <property name="ivy.jar.file" value="$ivy.jar.dir/ivy.jar" />

    <target name="download-ivy" unless="offline">

        <mkdir dir="$ivy.jar.dir"/>
        <!-- download Ivy from web site so that it can be used even without any special installation -->
        <get src="http://repo2.maven.org/maven2/org/apache/ivy/ivy/$ivy.install.version/ivy-$ivy.install.version.jar" 
             dest="$ivy.jar.file" usetimestamp="true"/>
    </target>

    <target name="init-ivy" depends="download-ivy">
      <!-- try to load ivy here from ivy home, in case the user has not already dropped
              it into ant's lib dir (note that the latter copy will always take precedence).
              We will not fail as long as local lib dir exists (it may be empty) and
              ivy is in at least one of ant's lib dir or the local lib dir. -->
        <path id="ivy.lib.path">
            <fileset dir="$ivy.jar.dir" includes="*.jar"/>
        </path>
        <taskdef resource="org/apache/ivy/ant/antlib.xml"
                 uri="antlib:org.apache.ivy.ant" classpathref="ivy.lib.path"/>
    </target>


    <path id="ivy.lib.path">
        <fileset dir="$ivy-support.lib.dir" includes="*.jar" />
    </path>
    <taskdef resource="org/apache/ivy/ant/antlib.xml" uri="antlib:org.apache.ivy.ant" classpathref="ivy.lib.path" loaderref="ivy.lib.loader" />

    <ivy:settings file="$ivy-support.build.dir/$ivy.settings.filename" />

    <property name="should.clean.ivy.cache" value="false" />

    <dirname property="ivy-support.build.dir" file="$ant.file.ivy-support" />
    <property name="ivy-support.lib.dir" location="$ivy-support.build.dir/ivy" />
    <property name="ivy.settings.filename" value="ivysettings.xml" />

    <path id="ivy.lib.path">
        <fileset dir="$ivy-support.lib.dir" includes="*.jar" />
    </path>
    <taskdef resource="org/apache/ivy/ant/antlib.xml" uri="antlib:org.apache.ivy.ant" classpathref="ivy.lib.path" loaderref="ivy.lib.loader" />

    <ivy:settings file="$ivy-support.build.dir/$ivy.settings.filename" />

    <target name="clean-ivy-cache" if="clean.ivy.cache.istrue">
        <ivy:cleancache />
    </target>
</project>

构建.xml

<project name="main" xmlns:ivy="antlib:org.apache.ivy.ant" default="compile">
    <description>Testing Script</description>
    <import file="common.xml" />

    <!--
    ================
    Build properties
    ================
    -->
    <property name="src.dir" location="src/org"/>
    <property name="build.dir" location="build"/>
    <property name="classes.dir" location="$build.dir/classes"/>
    <property name="test.classes.dir" location="$build.dir/test-classes"/>
    <property name="ivy.reports.dir"  location="$build.dir/ivy-reports"/>
    <property name="test.reports.dir"  location="$build.dir/test-reports"/>

    <!--
    ===========
    Build setup
    ===========
    -->
    <target name="init">
        <ivy:resolve file="ivy.xml" />

        <ivy:report todir='$ivy.reports.dir' graph='false' xml='false'/>

        <ivy:cachepath pathid="compile.path" conf="compile"/>
        <ivy:cachepath pathid="runtime.path" conf="runtime"/>
        <ivy:cachepath pathid="test.path"    conf="test"/>

        <mkdir dir="$classes.dir"/>
        <mkdir dir="$test.classes.dir"/>
        <mkdir dir="$test.reports.dir"/>
    </target>

    <!--
    ===============
    Compile target
    ===============
    -->
    <target name="compile" depends="init">
        <javac srcdir="$src.dir" destdir="$classes.dir" includeantruntime="true" debug="true" classpathref="runtime.path"/>
    </target>

    <!--
    =====================
    Build and run targets
    =====================
    -->
    <target name="run" depends="init-ivy">
        <java classname="org">
            <classpath>
                <path refid="runtime.path"/>
                <pathelement location="$classes.dir"/>
            </classpath>
        </java>
    </target>

    <!--
    =============
    Clean targets
    =============
    -->
    <target name="clean">
        <delete dir="$build.dir"/>
    </target>

    <target name="clean-all" depends="clean">
        <ivy:cleancache/>
    </target>

</project>

【问题讨论】：

您的错误究竟是什么？我注意到你的“运行”目标有一个“依赖”属性，它调用了一个与常春藤相关的目标，但不编译你的代码。这是问题吗？运行时缺少类，因为本地源尚未编译？最后你说它不能在 Eclipse 中工作。这是误导性的，因为 ivy 是一个 ANT 插件。您是否尝试过从命令行运行 ANT？

【参考方案1】：

是的，常春藤中有一个bug ..这是因此而发生的。看看人们给出的错误及其解决方案。它对我有用。解决方案是您必须禁用项目的保存时编译选项。检查这是否有帮助。