Question

当我使用ant构建使用libgdx的项目时，我收到一个奇怪的错误。它表示找不到类com.google.gwt.dom.client.ImageElement，但在代码中根本没有使用它。如何找到使这门课成为必要的内容？即使搜索整个项目也没有给出任何结果。它表示错误位于PixmapTextureAtlas.java:16（class source），但没有使用该ImageElement类的代码。当然，添加包含com.google.gwt.dom.client.ImageElement类的库有帮助，但我想弄清楚为什么需要这个类。

这是ant日志中告诉实际错误的地方：

Compiling 3 source files to /home/suseika/Projects/tendiwa/client/bin
/home/suseika/Projects/tendiwa/client/src/org/tendiwa/client/PixmapTextureAtlas.java:16: error: cannot access ImageElement
class file for com.google.gwt.dom.client.ImageElement not found

这是整个ant日志：

 /usr/lib/jvm/java-7-oracle/bin/java -Xmx128m -Xss2m -Dant.home=/opt/intellijidea/lib/ant -Dant.library.dir=/opt/intellijidea/lib/ant/lib -Dfile.encoding=UTF-8 -classpath /opt/intellijidea/lib/ant/lib/ant-apache-regexp.jar:/opt/intellijidea/lib/ant/lib/ant-swing.jar:/opt/intellijidea/lib/ant/lib/ant-apache-xalan2.jar:/opt/intellijidea/lib/ant/lib/ant-jdepend.jar:/opt/intellijidea/lib/ant/lib/ant-apache-resolver.jar:/opt/intellijidea/lib/ant/lib/ant-jsch.jar:/opt/intellijidea/lib/ant/lib/ant.jar:/opt/intellijidea/lib/ant/lib/ant-testutil.jar:/opt/intellijidea/lib/ant/lib/ant-launcher.jar:/opt/intellijidea/lib/ant/lib/ant-apache-bsf.jar:/opt/intellijidea/lib/ant/lib/ant-commons-logging.jar:/opt/intellijidea/lib/ant/lib/ant-netrexx.jar:/opt/intellijidea/lib/ant/lib/ant-junit.jar:/opt/intellijidea/lib/ant/lib/ant-commons-net.jar:/opt/intellijidea/lib/ant/lib/ant-apache-bcel.jar:/opt/intellijidea/lib/ant/lib/ant-antlr.jar:/opt/intellijidea/lib/ant/lib/ant-apache-log4j.jar:/opt/intellijidea/lib/ant/lib/ant-jai.jar:/opt/intellijidea/lib/ant/lib/ant-apache-oro.jar:/opt/intellijidea/lib/ant/lib/ant-jmf.jar:/opt/intellijidea/lib/ant/lib/ant-javamail.jar:/usr/lib/jvm/java-7-oracle/lib/tools.jar:/opt/intellijidea/lib/idea_rt.jar com.intellij.rt.ant.execution.AntMain2 -logger com.intellij.rt.ant.execution.IdeaAntLogger2 -inputhandler com.intellij.rt.ant.execution.IdeaInputHandler -buildfile /home/suseika/Projects/tendiwa/client/build.xml jar
build.xml
property
path
description
compile
ant
property
property
property
description
compile
mkdir
javac
jar
ant
property
description
_core_src_available
available
ontology
antcall
property
description
_core_src_available
available
_build_core
ant
property
property
compile
echo
/home/suseika/Projects/tendiwa/client
mkdir
javac
jar
jar
Building jar: /home/suseika/Projects/tendiwa/MainModule.jar
description
tempfile
mkdir
Created dir: /tmp/tendiwa373148820
unjar
Expanding: /home/suseika/Projects/tendiwa/MainModule.jar into /tmp/tendiwa373148820
Expanding: /home/suseika/Projects/tendiwa/tendiwa-backend.jar into /tmp/tendiwa373148820
Expanding: /home/suseika/Projects/tendiwa/tendiwa-ontology.jar into /tmp/tendiwa373148820
copy
Copying 1 file to /tmp/tendiwa373148820
java
Created item short_sword
Created item short_bow
Created item bucket
Created item boot
Created item steel_morningstar
Created item rifle_ammo
Created item handAxe
Created item iron_armor
Created item steel_mace
Created item jacket
Created item fedora
Created item wooden_arrow
Saving sources to /tmp/tendiwa373148820/ontology/src
tendiwa/resources/SoundTypes.java
tendiwa/resources/CharacterTypes.java
tendiwa/resources/ObjectTypes.java
tendiwa/resources/FloorTypes.java
tendiwa/resources/ItemTypes.java
tendiwa/resources/MaterialTypes.java
mkdir
mkdir
mkdir
Created dir: /tmp/tendiwa373148820/ontology/bin
javac
jar
Building jar: /home/suseika/Projects/tendiwa/tendiwa-ontology.jar
echo
Resources source code generated
ant
property
property
compile
echo
/home/suseika/Projects/tendiwa/client
mkdir
javac
jar
jar
jar
Building jar: /home/suseika/Projects/tendiwa/MainModule.jar
mkdir
javac
/home/suseika/Projects/tendiwa/client/build.xml:25: Compile failed; see the compiler error output for details.
    at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:1150)
    at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:912)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:390)
    at org.apache.tools.ant.Target.performTasks(Target.java:411)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
    at org.apache.tools.ant.Main.runBuild(Main.java:809)
    at org.apache.tools.ant.Main.startAnt(Main.java:217)
    at org.apache.tools.ant.Main.start(Main.java:180)
    at org.apache.tools.ant.Main.main(Main.java:268)
    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:606)
    at com.intellij.rt.ant.execution.AntMain2.main(AntMain2.java:30)
/home/suseika/Projects/tendiwa/client/build.xml (25:46)'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
Compiling 3 source files to /home/suseika/Projects/tendiwa/client/bin
/home/suseika/Projects/tendiwa/client/src/org/tendiwa/client/PixmapTextureAtlas.java:16: error: cannot access ImageElement
class file for com.google.gwt.dom.client.ImageElement not found
1 error
/home/suseika/Projects/tendiwa/client/build.xml:25: Compile failed; see the compiler error output for details.
    at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:1150)
    at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:912)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:390)
    at org.apache.tools.ant.Target.performTasks(Target.java:411)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
    at org.apache.tools.ant.Main.runBuild(Main.java:809)
    at org.apache.tools.ant.Main.startAnt(Main.java:217)
    at org.apache.tools.ant.Main.start(Main.java:180)
    at org.apache.tools.ant.Main.main(Main.java:268)
    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:606)
    at com.intellij.rt.ant.execution.AntMain2.main(AntMain2.java:30)
/home/suseika/Projects/tendiwa/client/build.xml:25: Compile failed; see the compiler error output for details.
    at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:1150)
    at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:912)
    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
    at org.apache.tools.ant.Task.perform(Task.java:348)
    at org.apache.tools.ant.Target.execute(Target.java:390)
    at org.apache.tools.ant.Target.performTasks(Target.java:411)
    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1399)
    at org.apache.tools.ant.Project.executeTarget(Project.java:1368)
    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
    at org.apache.tools.ant.Project.executeTargets(Project.java:1251)
    at org.apache.tools.ant.Main.runBuild(Main.java:809)
    at org.apache.tools.ant.Main.startAnt(Main.java:217)
    at org.apache.tools.ant.Main.start(Main.java:180)
    at org.apache.tools.ant.Main.main(Main.java:268)
    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:606)
    at com.intellij.rt.ant.execution.AntMain2.main(AntMain2.java:30)

Ant build completed with 3 errors one warning in 4s at 10/30/13 3:09 AM

以下是出现此错误的ant文件的一部分：

<path id="tendiwa.jars">
    <fileset dir="../libs">
        <include name="**/*.jar"/>
    </fileset>
    <pathelement path="../tendiwa-backend.jar"/>
    <pathelement path="../tendiwa-ontology.jar"/>
    <!--<fileset dir="/usr/share/java" includes="gwt*.jar"/>-->
</path>

<target name="compile">
    <ant dir="../MainModule" target="jar"/>
    <mkdir dir="bin"/>
    <javac destdir="bin" failonerror="true">
        <classpath>
            <path refid="tendiwa.jars"/>

            <!--temporary-->
            <pathelement path="../tendiwa-ontology.jar"/>
            <!--temporary-->
            <pathelement path="../MainModule.jar"/>
            <fileset dir="../libs" includes="**/*.jar"/>
        </classpath>
        <src>
            <pathelement path="Desktop/src"/>
            <pathelement path="src"/>
        </src>
    </javac>
</target>

Answer 1

给定的库可能具有它未提供的依赖项，因此您的代码需要间接。 PixmapTextureAtlas.java:16确实引用了此类，并且您使用PixmapTextureAtlas，因此您间接需要com.google.gwt.dom.client.ImageElement。

像Maven这样的工具可以添加依赖项/子依赖项并轻松管理它们。

Answer 2

我发现了为什么会这样。我不小心在classpath中添加了两个不同的jar，其中有两个不同的类com.badlogic.gdx.graphics.Pixmap变体，一个依赖于GWT，另一个是我需要的变种。问题是我不知道这种情况是可能的：）

项目编译需要一个不在任何地方使用的类

2 个答案: