Question

在JARing我的太空入侵者游戏之前，我测试了它。工作得很好。没有错误。现在，在我JAR之后，当我尝试运行它时，我在控制台中出现以下错误，以及上面的以下消息：

<terminated> SI[Java Application]C:\Program Files\Java\jre1.0.8_121\bin\javaw.exe(Dec 8, 2017, 5:52:28 PM)

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at sun.applet.AppletAudioClip.<init>(Unknown Source)
    at java.applet.Applet.newAudioClip(Unknown Source)
    at SIship.<init>(Unknown Source)
    at SIbase.<init>(Unknown Source)
    at SIpanel.userBaseAndEnemyInvaderCreation(Unknown Source)
    at SIpanel.resetFields(Unknown Source)
    at SIpanel.<init>(Unknown Source)
    at SI.<init>(Unknown Source)
    at SI$7.run(Unknown Source)
    at java.awt.event.InvocationEvent.dispatch(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$500(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.awt.EventQueue$3.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue.dispatchEvent(Unknown Source)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
    at java.awt.EventDispatchThread.run(Unknown Source)

我无法弄清问题是什么。除了命名几个类之外，它没有让我看到问题出在哪里。就我所见，JAR完美地运行程序，但现在我无法在Eclipse中运行它。

这是我的ANT JAR代码。关于什么可能出错的任何想法，如果有的话？

<?xml version="1.0" ?>
<project default="main">
    <property name="folder.source" value="../src/" />
    <property name="folder.class" value="../bin/" />
    <property name="jar.name" value="../spaceinvaders.jar" />
    <target name="main" depends="clean, compile, jar">
        <echo>success</echo>
    </target>
    <target name="compile">
        <echo>compiling...</echo>
        <javac srcdir="${folder.source}" destdir="${folder.class}" />
        <echo>done!</echo>
    </target>
    <target name="clean">
        <echo>cleaning...</echo>
        <delete dir="${folder.class}" includes="**/*" />
        <delete file="${jar.name}" />
        <echo>done!</echo>
    </target>
    <target name="jar">
        <echo>JARing...</echo>
        <jar destfile="${jar.name}">
            <fileset dir="${folder.class}">
                <include name="**/*.class" />
            </fileset>
            <fileset dir="${folder.source}">
                <include name="**/*.gif" />
            </fileset>
            <fileset dir="${folder.source}">
                <include name="**/*.wav" />
            </fileset>
            <manifest>
                <attribute name="Main-Class" value="SI" />
            </manifest>
        </jar>
        <echo>done!</echo>
    </target>
</project>

SIship.Java

import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.Graphics2D;
import java.awt.Image;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.SwingUtilities;

public abstract class SIship extends SIthing {
    protected Image imageDead;
    private AudioClip aud = Applet
            .newAudioClip(getClass().getResource("invaderkilled.wav"));

    protected boolean active = true;

    public SIship(int x, int y, int wid, int height, String hitImage) {
        super(x, y, wid, height);
        imageDead = getImage(hitImage);
    }

    protected boolean isItHit(SImissile mis) {
        if (active == false) {
            return false;
        }
        else {
            return this.getX() < mis.getX() + mis.getWidth()
                    && this.getX() + this.getWidth() > mis.getX()
                    && this.getY() < mis.getY() + mis.getHeight()
                    && this.getY() + this.getHeight() > mis.getY();
        }
    }

    protected void hit() {

        SwingUtilities.invokeLater(() -> aud.play());
        active = false;

    }

    @Override
    abstract public void draw(Graphics2D g2);

    protected Image getImage(String filename) {
        URL url = getClass().getResource(filename);
        ImageIcon icon = new ImageIcon(url);
        return icon.getImage();
    }
}

答案：我明白了。原来......

<delete dir="${folder.class}" includes="**/*" />

...每次运行时都会删除项目中的所有.classes。糟糕。

程序在JAR中工作，而不是在Eclipse中工作

0 个答案: