动态加载jar中的类

URL url1 = new URL("file:D:/workspace/spider/plugin/plugin_fat.jar");
//加载类
  
URLClassLoader loader = new URLClassLoader(new URL[] { url1 }, Thread.currentThread().getContextClassLoader());  
Class<?> cls = loader.loadClass("com.test.plugins.impl.LaserPrint"); 
//创建实例 
IPrint print = (IPrint) cls.newInstance();  
//调用
System.out.println(print.print("test"));

package com.test.plugins.impl;

import com.test.plugins.IPrint;
public class LaserPrint implements IPrint
{

	@Override
	public String print(String param)
	{
		String result = "log time: " + System.currentTimeMillis()  + param;
		return result;
	}

}

package com.test.plugins;

public interface IPrint
{

	String print(String param);
	
}