java.lang.NoClassDefFoundError：org / apache / commons / collections / ReferenceMap

Question

Java真的是新手，还是讲西班牙语的人，所以，请尽我所能帮助您理解我:)。我制作了一个程序，该程序管理用于存储客户端，有关客户端的信息等的mysql数据库。并生成（或尝试...）报告。我从Eclipse Market（BTW，使用Eclipse Kepler）安装了JasperReports。在学习了一些教程之后，我开始按参数创建报告。它只是识别一个客户端的一个参数。那不是问题。当我单击我的按钮以生成报告时出现问题，该报告包含以下代码：

JButton btnOk = new JButton("OK");
    btnOk.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            String doc = jftxtDni.getText();
            String sql;
            boolean respuesta = false;
            ConexionBaseDatos cc = new ConexionBaseDatos();

            sql = "SELECT * FROM clientes WHERE DNI = '"+doc+"'";

            rs = cc.Consultar(sql);

                try 
                {
                    while (rs.next())
                    {
                    respuesta = true;
                    }
                }
                catch (SQLException e) 
                {
                    JOptionPane.showMessageDialog(null, "error sql: "+e.getMessage());
                }    

                if (respuesta)
                {
                    ConexionBaseDatos cd = new ConexionBaseDatos();
                    Connection cn = cd.Conectar();
                    JasperReport jr = null;
                    String archivo = "src/reportes/Tree.jasper";
                    try
                    {
                        HashMap<String, Object> parametro = new HashMap<String, Object>();
                        parametro.put("dni", doc);
                        jr = (JasperReport) JRLoader.loadObjectFromFile(archivo);
                        JasperPrint jp = JasperFillManager.fillReport(jr,parametro,cn);
                        JasperViewer jv = new JasperViewer(jp);
                        jv.setVisible(true);
                        jv.setTitle("Informe de cliente");

                    } 
                    catch (JRException e)
                    {
                        JOptionPane.showMessageDialog(null, "error Jasper: "+e.getMessage());;
                    }

                }   
                else
                {
                    JOptionPane.showMessageDialog(null, "No existe el cliente en la base de datos, verifique.");
                }

                }
            }
        )

尽管变量名称用西班牙语命名，但它捕获用户键入的变量，连接到数据库，并通过其“ dni”检查该用户是否存在，如果存在，则生成报告，否则，将生成消息错误。当我第一次执行它时，出现apache.commons.logging没找到，这解决了导入apache commons库的问题。但是在那之后，错误就是我给这个主题命名的错误。我说：简单的蛋糕，下载的Apache Commons Collections，进口的罐子……就是这样！我以为...但是没有办法..我得到了：

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: org/apache/commons/collections/ReferenceMap
at net.sf.jasperreports.extensions.DefaultExtensionsRegistry.<init>(DefaultExtensionsRegistry.java:97)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at net.sf.jasperreports.engine.util.ClassUtils.instantiateClass(ClassUtils.java:59)
at net.sf.jasperreports.extensions.ExtensionsEnvironment.createDefaultRegistry(ExtensionsEnvironment.java:82)
at net.sf.jasperreports.extensions.ExtensionsEnvironment.<clinit>(ExtensionsEnvironment.java:69)
at net.sf.jasperreports.engine.util.JRStyledTextParser.<clinit>(JRStyledTextParser.java:83)
at net.sf.jasperreports.engine.fill.JRBaseFiller.<init>(JRBaseFiller.java:123)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:88)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:103)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.<init>(JRVerticalFiller.java:61)
at net.sf.jasperreports.engine.fill.JRFiller.createFiller(JRFiller.java:179)
at net.sf.jasperreports.engine.fill.JRFiller.fill(JRFiller.java:81)
at net.sf.jasperreports.engine.JasperFillManager.fill(JasperFillManager.java:446)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:849)
at formularios.ImprimirCliente$2.actionPerformed(ImprimirCliente.java:143)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$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$200(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: org.apache.commons.collections.ReferenceMap
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)
... 55 more

...如此...我再次检查了该库是否正常，并且在那儿，但是由于某种原因，它看起来像eclipse或java或某种外星人都找不到它..无论如何，我确实研究了整个互联网，并发现此错误，这主要是通过导入公共资源集合解决的，而不是我的情况。Eclipse Kepler，Java 7和Apache Commons 4.0。任何模糊的想法..？非常感谢您抽出宝贵的时间阅读该书，对不起我的英语，并等待些时间..：D

Answer 1

好了，问题解决了！我只需要将集合降级到3.2.1，就可以正常工作，部分原因是因为我对其他类（joda-time，commons-digester和javax-servlet）一直有错误。在某些情况下，无法下载最新版本，而只能下载前一个版本。因此，此后我的报告就完美无缺了。非常感谢您的帮助！！:)