错误: 找不到或无法加载主类 com.imooc.dom4j.XPathTestor

程序没报错，但是运行的时候显示：错误: 找不到或无法加载主类 com.imooc.dom4j.XPathTestor

package com.imooc.dom4j;

import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

public class XPathTestor {
	public void xpath(String xpathExp) {
		String file="C:/eclipse/workspace/xml/bin/hr.xml";
		SAXReader reader=new SAXReader();
		try {
			Document document=reader.read(file);
			List<Node> nodes=document.selectNodes(xpathExp);
			for(Node node:nodes) {
				Element emp=(Element)node;
				System.out.println(emp.attributeValue("no"));
				System.out.println(emp.elementText("name"));
				System.out.println(emp.elementText("age"));
				System.out.println(emp.elementText("salary"));
				System.out.println("***************************");
			}
		} catch (DocumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public static void main(String[] args) {
		XPathTestor testor=new XPathTestor();
		testor.xpath("/hr/employee");
	}
}