Question

我正在编写一个使用以下代码的ant任务：

public class Klazz extends Task{    
    public void execute() throws BuildException{

        HtmlUnitDriver driver = new HtmlUnitDriver();
        driver.get("file:///C:/sample/alltests-fails.html");
}

在eclipse中，名为“ test-project ”的项目使用“ libs ”文件夹，其中包含将要添加到类路径中的jar（ ant.jar，selenium-server-standalone-2.44.0.jar ）。如果我在Eclipse中运行代码它工作正常但在作为ant任务运行时会抛出java.lang.ExceptionInInitializerError。下面是build.xml片段，用于创建jar（名为 custom-task.jar ）文件，该文件需要放在％ant_home％\ lib文件夹中。

<target name="jar" depends="compile" >
        <mkdir dir="build/jar" />
        <jar destfile="${env.ANT_HOME}/lib/custom-task.jar">
            <fileset dir="build/classes" />         
            <restrict>
                <name name="**/*.class" />
                <archives> 
                    <zips>
                        <fileset dir="${basedir}/libs/" includes="**/*.jar" />
                    </zips>
                </archives>
            </restrict>
        </jar>
    </target>

在通过上面的“jar”任务创建jar时，可能是类路径中未正确添加的外部jar /类，导致一些缺少的类文件导致 ExceptionInInitializerError 。感谢任何帮助。

下面的

是堆栈跟踪：

java.lang.ExceptionInInitializerError
        at org.cyberneko.html.HTMLScanner.scanEntityRef(HTMLScanner.java:1415)
        at org.cyberneko.html.HTMLScanner$ContentScanner.scan(HTMLScanner.java:2
059)
        at org.cyberneko.html.HTMLScanner.scanDocument(HTMLScanner.java:920)
        at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:499
)
        at org.cyberneko.html.HTMLConfiguration.parse(HTMLConfiguration.java:452
)
        at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
        at com.gargoylesoftware.htmlunit.html.HTMLParser$HtmlUnitDOMBuilder.pars
e(HTMLParser.java:926)
        at com.gargoylesoftware.htmlunit.html.HTMLParser.parse(HTMLParser.java:2
45)
        at com.gargoylesoftware.htmlunit.html.HTMLParser.parseHtml(HTMLParser.ja
va:191)


       at com.gargoylesoftware.htmlunit.DefaultPageCreator.createHtmlPage(Defau
ltPageCreator.java:268)
        at com.gargoylesoftware.htmlunit.DefaultPageCreator.createPage(DefaultPa
geCreator.java:156)
        at com.gargoylesoftware.htmlunit.WebClient.loadWebResponseInto(WebClient
.java:455)
        at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:329)
        at com.gargoylesoftware.htmlunit.WebClient.getPage(WebClient.java:394)
        at org.openqa.selenium.htmlunit.HtmlUnitDriver.get(HtmlUnitDriver.java:4
77)
        at org.openqa.selenium.htmlunit.HtmlUnitDriver.get(HtmlUnitDriver.java:4
66)

at mypkg.Klazz.execute(Klazz.java:15)

       at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
        at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.jav
a:106)
        at org.apache.tools.ant.Task.perform(Task.java:348)
        at org.apache.tools.ant.Target.execute(Target.java:435)
        at org.apache.tools.ant.Target.performTasks(Target.java:456)
        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
        at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExe
cutor.java:41)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
        at org.apache.tools.ant.Main.runBuild(Main.java:851)
        at org.apache.tools.ant.Main.startAnt(Main.java:235)
        at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
        at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
Caused by: java.lang.NullPointerException
        at java.util.Properties$LineReader.readLine(Properties.java:434)
        at java.util.Properties.load0(Properties.java:353)
        at java.util.Properties.load(Properties.java:341)
        at org.cyberneko.html.HTMLEntities.load0(HTMLEntities.java:101)
        at org.cyberneko.html.HTMLEntities.<clinit>(HTMLEntities.java:53)
        ... 33 more

Total time: 2 seconds

Answer 1

如果遇到任何课程加载困难，我会假设会出现NoClassDefFoundError或ClassNotFoundException

ExceptionInInitializerError通常不应该引起注意，因为它只是说“嘿，程序员，在初始化块中发生异常”

有关初始化块here

的更多信息

因此，处理NPE将解决问题，但遗憾的是我无法访问可能导致此问题的代码。让我知道，我将编辑答案。

Answer 2

@Vlad Ilie感谢您一看，现在已经解决了..问题在于jar创建ant脚本。 jar创建的早期ant任务无法在类路径中绑定所有jar并导致... classnotfoundexception，这反过来导致ExceptionInInitializerError和NullPointerException。

下面是修复的“jar”任务，它可以成功地添加类路径中的所有jar。

<target name="jar" depends="compile">       
        <jar destfile="${env.ANT_HOME}/lib/custom-task.jar" basedir="build/classes" >           
            <zipgroupfileset dir="${basedir}/libs/" includes="*.jar"/>      
        </jar>
    </target>

上面我使用的是zipgroupfileset，非常方便。

HtmlUnitDriver抛出java.lang.ExceptionInInitializerError

2 个答案: