如何在 Java 中使用 Selenium Webdriver 获取标签值

Question

I tried to use this code to make my experiment. I have tried to make a system to get the data from a website and use the lagrange interpolation method to create a polynomial. I am studying Selenium with Java to do this. Take a look at what I've developed.

package com.gustavo.seleniumTest;

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

public class seleniumTest {

public static void main(String[] args) {

    System.setProperty("webdriver.gecko.driver", "/home/gustavo/geckodriver");
    WebDriver driver = new FirefoxDriver();

    String valor;

    driver.get("http://cotacoes.economia.uol.com.br/acao/cotacoes-historicas.html?codigo=PETR4.SA&size=200&page=1&period=");
    valor = driver.findElement(By.xpath(".//*[@class='odd']")).getText();
    System.out.println(valor);
}

Note: I'm using linux and Firefox.

Answer 1

You need to modify your locator and if you want to fetch all the elements then you need to use driver.findElements() method.

Try the below XPath locator which will identify number of rows that table has:

String xPath = "//table[@id='tblInterday']/tbody//tr";

and you can get the size of the rows like this:

int rows = driver.findElements(By.xpath(xPath)).size();

and you can loop through whole rows using loops for example for loop like below:

for(int i=1;i<rows;i++) {

}

The below XPath will identity number of columns in each row based on the row index number:

String xPath = "//table[@id='tblInterday']/tbody//tr[row index number]/td";

As there are many rows, you can pass the row index to the above XPath like below:

for(int i=1;i<rows;i++) {
    driver.findElements(By.xpath(xPath+"["+i+"]/td"));
}

As we are using the driver.findElements() method above, it will hold all the columns elements, we can loop through and print each of them like below:

for(WebElement element : driver.findElements(By.xpath(xPath+"["+i+"]/td"))) {
    System.out.print(element.getText()+"\t");
}

Replace

driver.findElements(By.xpath(xPath+"["+i+"]/td")).forEach(e -> System.out.print(e.getText()+"\t"));

with

for(WebElement element : driver.findElements(By.xpath(xPath+"["+i+"]/td"))) {
        System.out.print(element.getText()+"\t");
    }

If you want to print normally.

Below is the whole code using Java 8 :

import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

public class SeleniumTest {

    public static void main(String[] args) {
        System.setProperty("webdriver.chrome.driver", "C:\\NotBackedUp\\chromedriver.exe");
        WebDriver driver = new ChromeDriver();

        driver.get("http://cotacoes.economia.uol.com.br/acao/cotacoes-historicas.html?codigo=PETR4.SA&size=200&page=1&period=");
        String xPath = "//table[@id='tblInterday']/tbody//tr";
        int rows = driver.findElements(By.xpath(xPath)).size();
        for(int i=1;i<rows;i++) {
            driver.findElements(By.xpath(xPath+"["+i+"]/td")).forEach(e -> System.out.print(e.getText()+"\t"));
            System.out.println();
        }
    }
}

I hope it helps...

Answer 2

Post the element in the DOM(the whole thing between the tags).

Your code will work if it's a text inside the tag but if the text is inside a value parameter for example, you will need to getProperty("value") in order to extract it from the element.