net.sf.jga.parser.JFXGParser的ClassNotFoundException

Question

我试图理解我的代码有什么不正确并试图理解以下错误：

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: net/sf/jga/parser/JFXGParser
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$100(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at org.jdesktop.dataset.DataSet.<init>(Unknown Source)
    at com.datamotion.DMNet.getMailbox(DMNet.java:358)
    at com.datamotion.Mailbox$1.actionPerformed(Mailbox.java:50)
    at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
    at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
    at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
    at java.awt.Component.processMouseEvent(Unknown Source)
    at javax.swing.JComponent.processMouseEvent(Unknown Source)
    at java.awt.Component.processEvent(Unknown Source)
    at java.awt.Container.processEvent(Unknown Source)
    at java.awt.Component.dispatchEventImpl(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
    at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
    at java.awt.Container.dispatchEventImpl(Unknown Source)
    at java.awt.Window.dispatchEventImpl(Unknown Source)
    at java.awt.Component.dispatchEvent(Unknown Source)
    at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
    at java.awt.EventQueue.access$400(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$1.doIntersectionPrivilege(Unknown Source)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.awt.EventQueue$4.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.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)
Caused by: java.lang.ClassNotFoundException: net.sf.jga.parser.JFXGParser
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 51 more

唯一有问题的代码是以下行：

DataSet data = new DataSet();

DataSet是0.8 swingx api / library的一部分。我真的可以帮上忙。

更新： 我的进口商品：

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.StringReader;
import java.rmi.RemoteException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import javax.mail.Message;
import javax.mail.Message.RecipientType;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.jdesktop.dataset.DataSet;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

Answer 1

这个答案可能是在问题发布后5个月，但我希望它会对某人有所帮助。

我正在开发一个没有问题的Java应用程序，但是一旦我开始使用SwingLabs DataSet，我就无法运行应用程序，并使用JFXGParser接收ClassNotFoundException。

我用一行代码创建了一个新的应用程序来创建一个DataSet

import org.jdesktop.dataset.DataSet;
public class Main {
    public static void main(String[] args) {
        DataSet ds = new DataSet("ds");
    }
}

以下是包浏览器的快照，以显示引用的内容。

网上的一些答案提到了Classpath，所以我检查了我的，项目似乎有了它，所以我仍然感到困惑。我决定做一些我认为不会起作用的事情，但事实确实如此。我注意到引用位于“DataSetTester（默认类路径）”文件夹中。因此，我决定将jar添加到根“User Entries”类路径中。一旦我这样做，应用程序运行正常。

注意：可能不需要某些罐子，但这是我使用的设置。 DataSet对象是databinding-0.8.0.jar的一部分，但我认为jga-0.7.2-crrl.jar也是必需的。

Step by Steps（对于Eclipse）：

1. 创建新的Java应用程序
2. 转到：项目＆gt;属性＆gt; Java构建路径＆gt; “库”选项卡
3. 使用“添加外部JAR ...”
添加jar文件
4. 编写代码;如果正确添加了罐子，Eclipse应该有自动填充工作
5. 运行应用程序并接收ClassNotFoundException
6. 使用debug
确定哪个jar具有导致异常的类
7. 转到：项目＆gt;属性＆gt;运行/调试设置
8. 选择适合启动配置的对象，然后单击“编辑...”
9. 转到：Classpath选项卡
10. 选择“用户条目”，然后点击“添加外部JAR ...”
11. 添加库中使用的相同jar文件
12. 运行应用程序（可能需要执行清理）