使用 JavascriptExecutor 检查页面源时出现 Nullpointerexception

Question

我需要检查网站上是否有文字。根据我试图避免 getPageSource()。我需要在各种文件中使用我的函数，所以我想我可以在不同的文件中制作它并只写一次代码。

这是一个文件，我只是为了检查页面源而写的：

package pl.mainfolder.tests.selenium;

import static org.junit.Assert.fail;

import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.WebDriver;

public class CheckSource {
private WebDriver driver;

public void CheckSite(String textToBeChecked, String error)
        throws Exception {
    Object test = (((JavascriptExecutor) driver)
            .executeScript("return document.body.innerHTML;"));
    if (!((String) test).contains(textToBeChecked)) {
        fail(error);
    }
}
}

我尝试使用以下代码启动该代码：

package pl.mainfolder.tests.selenium;

import static org.junit.Assert.fail;

import java.util.concurrent.TimeUnit;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.openqa.selenium.By;
import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.WebDriver;

import pl.mainfolder.tests.selenium.utils.WebDriverUtil;

public class LoginTest {
private WebDriver driver;
private String baseUrl;
private final StringBuffer verificationErrors = new StringBuffer();
public CheckSource Source = new CheckSource();

@Before
public void setUp() throws Exception {
    driver = WebDriverUtil.getFirefoxWebDriver();
    driver.manage().deleteAllCookies();
    baseUrl = "https://google.com/";
    driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
}

@Test
public void Login() throws Exception {
    driver.get(baseUrl);
    Source.CheckSite("Log in", "Error1");
(...)

仍然出现 NullPointerExcepiton 错误

java.lang.NullPointerException
at pl.mainfolder.tests.selenium.CheckSource.CheckSite(CheckSource.java:14)
at pl.mainfolder.tests.selenium.LoginPLTest.Login(LoginPLTest.java:33)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)
at org.junit.runners.ParentRunner.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access[=12=]0(ParentRunner.java:50)
at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:292)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

我尝试使用 try-catch，但检查代码无法正常工作（一切都很好，绝对没有问题，即使网站上没有文本 "Logggginnnnn"）并尝试混合它与 "if" （再次相同）尝试添加 else{} 再次导致 NPE 错误。

当我粘贴代码时

public void CheckSite(String textToBeChecked, String error)
    throws Exception {
Object test = (((JavascriptExecutor) driver)
        .executeScript("return document.body.innerHTML;"));
if (!((String) test).contains(textToBeChecked)) {
    fail(error);
}
}

直接访问所有文件，效果很好。

我该如何处理？

Answer 1

是的，错误确实是因为驱动程序未在 class CheckSource 中初始化。您可能需要进行以下更改。

更改登录测试

@Test
public void Login() throws Exception {
    driver.get(baseUrl);
    Source.CheckSite("Log in", "Error1",driver);// pass the instantiated driver object.

}

在class CheckSource

public void CheckSite(String textToBeChecked, String error,WebDriver driver)
        throws Exception {
    Object test = (((JavascriptExecutor) driver)
            .executeScript("return document.body.innerHTML;"));
    if (!((String) test).contains(textToBeChecked)) {
        fail(error);
    }
}

这不会给你 NPE，此外它正在通过 Text=Sign in 的测试用例，提供。

注意：如果您在问题中提到的检查登录，它将无法通过测试。这对我有用。试一试。

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