首先要通过向下转型 JavascriptExecutor js = (JavascriptExecutor) driver; 转为JavascriptExector对象

然后再调用executeScript()方法来执行JS。

例：

1. 打开Google首页

2. 通过JS获取网页中的title  --- document.title

3. 获得网页中链接的数量 ----var links = document.getElementsByTagName('A'); return links.length

具体实现如下

    package com.example.tests;        import static org.junit.Assert.*;        import org.junit.*;        import org.openqa.selenium.*;        import org.openqa.selenium.ie.InternetExplorerDriver;                public class test {            @Test            public void testJavaScriptCalls() {                WebDriver driver = new InternetExplorerDriver();                driver.get("http://www.google.com.hk");                JavascriptExecutor js = (JavascriptExecutor) driver;                String title = (String) js.executeScript("return document.title");                assertEquals("Google", title);                long links = (Long) js.executeScript("var links = "                        + "document.getElementsByTagName('A'); "                        + "return links.length");                assertEquals(32, links);                driver.close();            }        }