启动firefox浏览器报错，不知道问题出在哪里，求解救

package com.selenium.study;
import org.openqa.selenium.*;
import org.openqa.selenium.firefox.FirefoxDriver;
public class study3 {
	public static void main(String[] args) {
			//实例化一个对象Firefox
			WebDriver driver;
			System.setProperty("webdriver.firefox.bin","C:\\Program Files\\Mozilla Firefox\\firefox.exe");
			driver = new FirefoxDriver();
			String testurl="http://www.baidu.com";
			driver.get(testurl);
			driver.quit();
	
	
	
	}
}

报错：

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/base/Function

at com.selenium.study.study3.main(study3.java:9)

Caused by: java.lang.ClassNotFoundException: com.google.common.base.Function

at java.net.URLClassLoader.findClass(URLClassLoader.java:381)

at java.lang.ClassLoader.loadClass(ClassLoader.java:424)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)

at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

... 1 more