java – 非常简单的Apache-commons配置示例抛出NoClassDefFoundError

我正在尝试测试Apache-commons配置库用户指南中有关声明和创建bean的a very simple example.我几乎逐字地复制了示例中的代码,但是我得到了一个N​​oClassDefFoundError异常.

这是我正在使用的xml文件 – windowcongif.xml：

<?xml version="1.0" encoding="ISO-8859-1" ?>
<config>
  <gui>
    <windowManager config-class="test.DefaultwindowManager"
      closable="false" resizable="true" defaultWidth="400"
      defaultHeight="250">      
    </windowManager>
  </gui>
</config>

这是WindowManager.java文件中的代码：

package test;
public interface WindowManager {}

这是DefaultwindowManager.java文件中的代码：

package test;
public class DefaultwindowManager  implements WindowManager {
    private boolean resizable;
    private boolean closable;
    private int defaultWidth;
    private int defaultHeight;
}

这是Main.java文件中的代码：

package test;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.XMLConfiguration;
import org.apache.commons.configuration.beanutils.BeanDeclaration;
import org.apache.commons.configuration.beanutils.BeanHelper;
import org.apache.commons.configuration.beanutils.XMLBeanDeclaration;

public class Main {
    public static void main(String[] args) throws ConfigurationException {
        XMLConfiguration config = new XMLConfiguration("windowconfig.xml");
        BeanDeclaration decl = new XMLBeanDeclaration(config, "gui.windowManager");
        WindowManager wm = (WindowManager) BeanHelper.createBean(decl);
    }
}

这是运行时的输出：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/beanutils/PropertyUtils
    at org.apache.commons.configuration.beanutils.BeanHelper.initProperty(BeanHelper.java:269)
    at org.apache.commons.configuration.beanutils.BeanHelper.initBeanProperties(BeanHelper.java:229)
    at org.apache.commons.configuration.beanutils.BeanHelper.initBean(BeanHelper.java:166)
    at org.apache.commons.configuration.beanutils.Defaultbeanfactory.initBeanInstance(Defaultbeanfactory.java:108)
    at org.apache.commons.configuration.beanutils.Defaultbeanfactory.createBean(Defaultbeanfactory.java:64)
    at org.apache.commons.configuration.beanutils.BeanHelper.createBean(BeanHelper.java:336)
    at org.apache.commons.configuration.beanutils.BeanHelper.createBean(BeanHelper.java:358)
    at org.apache.commons.configuration.beanutils.BeanHelper.createBean(BeanHelper.java:372)
    at test.Main.main(Main.java:23)
Caused by: java.lang.classNotFoundException: org.apache.commons.beanutils.PropertyUtils
    at java.net.urlclassloader$1.run(urlclassloader.java:366)
    at java.net.urlclassloader$1.run(urlclassloader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.urlclassloader.findClass(urlclassloader.java:354)
    at java.lang.classLoader.loadClass(ClassLoader.java:423)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.classLoader.loadClass(ClassLoader.java:356)
    ... 9 more

我如何使这个简单的例子有效？

我正在使用版本1.9的commons-configuration软件包,在将依赖项放在pom.xml文件中后由IntelliJ IDEA自动导入,以及在Windows 8 64位上运行的java版本1.7.0_17.

解决方法:

在您的类中导入org.apache.commons.beanutils.PropertyUtils.