关于 Exception in thread "main" java.lang.NoClassDefFoundError: org/xml/sax/helpers/DefaultHandler
自己定义了一个xml文件的读取class
import org.xml.sax.*;
import javax.xml.parsers.*;
import java.io.IOException;
import org.xml.sax.helpers.DefaultHandler;
public class BookCounter extends DefaultHandler {}
编译通过,但是在执行时,出现了exception.如下:
Exception in thread "main" java.lang.NoClassDefFoundError: org/xml/sax/helpers/DefaultHandler
at java.lang.ClassLoader.defineClass0(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$1(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 java.lang.ClassLoader.loadClassInternal(Unknown Source)
不知道是什么原因.
1.是所包含的package不存在?
2.需要down什么库么?
3.路径设置有问题?