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

java xml apache-commons-config

2022-09-02 05:17:09

我试图测试Apache-commons配置库用户指南中给出的一个关于声明和创建bean的非常简单的例子。我几乎逐字逐句地复制了示例中的代码，但是我得到了一个NoClassDefFoundError异常。

以下是我正在使用的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>

以下是文件中的代码：WindowManager.java

package test;
public interface WindowManager {}

以下是文件中的代码：DefaultWindowManager.java

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

以下是文件中的代码：Main.java

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);
    }
}

以下是运行时的输出：

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

如何使这个简单的示例起作用？

我使用的是commons-configuration package的1.9版本，由IntelliJ IDEA在将依赖项放入文件后自动导入，以及Windows 8 64bit上运行的Java版本1.7.0_17。pom.xml

答案 1

我遇到了同样的问题，我添加了这个依赖关系：

<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.3</version>
</dependency>

答案 2

导入到您的课程中。org.apache.commons.beanutils.PropertyUtils