java.lang.NullPointerException 无法调用“org.openqa.selenium.WebElement”因为 this.webelement = null;

Question

我正在尝试在google字段上发送Keys()，并且能够使用正常的xpath来执行此操作，例如：-

driver.findElement(By.name("q")).sendKeys("Gmail");

但在使用 @FindBy 方法时出现 nullpointerException ：-

@FindBy(how = How.XPATH, using = "//input[@name='q']") 公共 WebElement googlesearchfield; googlesearchfield.sendKeys("Gmail");

package BasicTestCases;

import org.testng.annotations.Test;
import pages.*;
import Utility.TestConfiguration;
import bsh.This;

public class TC02_Login extends TestConfiguration{

//  private GooglePage google;
    
    
    @Test
    public void Login()
    {
        try
    {
        driver.get(prop.getProperty("Google"));
        GooglePage googlePage = new GooglePage();
        googlePage.gmaillogin();
        waitforpageload();
        System.out.println("end of login tc02");
        
    }
        catch (Exception e) {
            // TODO: handle exception
        }
    }
    
}
package pages;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.support.FindBy;
import org.openqa.selenium.support.How;

import Utility.TestConfiguration;

public class GooglePage extends TestConfiguration{
    
    
    @FindBy(how = How.XPATH, using = "//input[@name='q']")
    public WebElement googlesearchfield;
    

    @FindBy(how = How.XPATH, using = "//a[text()='Gmail']")
    public WebElement gmailclick;
    
    @FindBy(how =  How.XPATH, using = "//a[text()='Gmail']")
    public WebElement tryf;
    
    public void gmaillogin()
    {
        try {
            googlesearchfield.sendKeys("Gmail");

        System.out.println("entered");
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    
    
}

我无法解决这个空指针异常为什么会来。