Webdriver Xpath性能

Question

评估长xpath而不是短xpath所需的时间有很大差异吗？
防爆.有没有之间的性能差异
/div[@id = 'id1']/label[contains(text(), 'Hello')/../../descendant::input
和
//input

使用By.id("id1")
和之间的区别怎么样？
By.Xpath("//*[@id='id1']")

Answer 1

我很高兴你问,我发现答案令人惊讶.

• 短xpath比长xpath快,但不是很多
• 在Firefox上按名称搜索比长xpath快,但是使用短xpath(有时更快)的死热
• 在Internet Explorer,By.name是多少比慢的XPath

这似乎是面对Simon Stewart给出的指导:IE的xpath性能,所以我会带着一点点盐,但在下面的代码中,它非常一致.

我写了一个快速测试来说明这一点.它会在Google上搜索搜索框

package com.PeterNewhook;

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.ie.InternetExplorerDriver;

public class FooTest {

public static void main(String[] args) {
    long start;
    long end;
    WebDriver driver;
    String longXpath = "/html/body/span[@id='main']/center/span[@id='body']/center/form/table/tbody/tr/td[2]/div[@class='ds']/input[@name='q']";
    String shortXpath = "//input[@name='q']";
    String elementId = "q";

    System.out.println("Using Firefox driver.");
    driver = new FirefoxDriver();
    driver.get("http://google.com");
    start = System.nanoTime();
    driver.findElement(By.xpath(longXpath));
    end = System.nanoTime()-start;
    System.out.println("The long XPath lookup took " + (double)end/1000000000.0 + " seconds.");
    start = System.nanoTime();
    driver.findElement(By.xpath(shortXpath));
    end = System.nanoTime() - start;
    System.out.println("The short XPath lookup took " + (double)end / 1000000000.0 + " seconds.");
    start = System.nanoTime();
    driver.findElement(By.name(elementId));
    end = System.nanoTime() - start;
    System.out.println("The By.name lookup took " + (double)end / 1000000000.0 + " seconds.");
    driver.close();

    System.out.println("\nUsing Internet Explorer driver.");        
    driver = new InternetExplorerDriver();
    driver.get("http://google.com");
    start = System.nanoTime();
    driver.findElement(By.xpath(longXpath));
    end = System.nanoTime()-start;
    System.out.println("The long XPath lookup took " + (double)end/1000000000.0 + " seconds.");
    start = System.nanoTime();
    driver.findElement(By.xpath(shortXpath));
    end = System.nanoTime() - start;
    System.out.println("The short XPath lookup took " + (double)end / 1000000000.0 + " seconds.");
    start = System.nanoTime();
    driver.findElement(By.name(elementId));
    end = System.nanoTime() - start;
    System.out.println("The By.name lookup took " + (double)end / 1000000000.0 + " seconds.");
    driver.close();
}
}

这给出了输出:

使用Firefox驱动程序.
长XPath查找耗时0.13667022秒.
短XPath查找花了0.024628577秒.
By.name查找花了0.025209911秒.

使用Internet Explorer驱动程序.
漫长的XPath查找耗时0.196125248秒.
短XPath查找耗时0.164044262秒.
By.name查找耗时1.005109964秒.