Question

我收到一个“线程异常”主“java.lang.NullPointerException”错误，我不知道如何在这种情况下修复它。该应用程序将通过设置并开始打开Firefox，但随后Firefox将在下一步崩溃。该程序应该在登录我们的站点时检查Glassfish服务器是否仍在工作。

run:

setUp

testExample
Exception in thread "main" java.lang.NullPointerException
    at spidamin.Example.testExample(Spidamin.java:32)
    at spidamin.Example.main(Example.java:68)
C:\Users\user\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1
BUILD FAILED (total time: 8 seconds)

程序：

package example;

import java.io.IOException;
import java.util.regex.Pattern;
import java.util.concurrent.TimeUnit;
import org.junit.*;
import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.*;
import org.openqa.selenium.*;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.support.ui.Select;

public class Example {

    private WebDriver driver;
    private String baseUrl;
    private boolean acceptNextAlert = true;
    private StringBuffer verificationErrors = new StringBuffer();

    @Before
    public void setUp() throws Exception {
        System.out.println("\nsetUp");
        driver = new FirefoxDriver();
        baseUrl = "http://example.com/";
        driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
    }

    @Test
    public void testExample() throws Exception {
        System.out.println("testExample");
        driver.get(baseUrl + "/portal/web/guest"); <------------------- Line 32
        driver.findElement(By.name("_58_login")).clear();
        driver.findElement(By.name("_58_login")).sendKeys("kyle.hoover@example.net");
        driver.findElement(By.id("_58_password")).clear();
        driver.findElement(By.id("_58_password")).sendKeys("password here");
        driver.findElement(By.cssSelector("input[type=\"submit\"]")).click();
        driver.findElement(By.linkText("You are signed in as"));
        driver.findElement(By.linkText("Sign Out")).click();
    }

    @After
    public void tearDown() throws Exception {
        System.out.println("tearDown");
        driver.quit();
        String verificationErrorString = verificationErrors.toString();
        if (!"".equals(verificationErrorString)) {
            fail(verificationErrorString);
            Process i = Runtime.getRuntime().exec("cmd /c start \"C:\\Users\\user\\Desktop\\Tests\\Test.bat\"");
        }
    }

    public boolean isElementPresent() throws IOException {
        System.out.println("isElementPresent");
        try {
            System.out.println("True");
            driver.findElement(By.linkText("You are signed in as"));
            return true;
        } catch (NoSuchElementException e) {
            System.out.println("false");
            Process i = Runtime.getRuntime().exec("cmd /c start \"C:\\Users\\user\\Desktop\\Tests\\Test.bat\"");
            return false;
        }
    }

    public static void main(String[] args) throws Exception {
        new Example().setUp();
        new Example().testExample(); <------------------- Line 68
        new Example().isElementPresent();
        new Example().tearDown();
        System.out.println("\nprogram finished");
    }
}

Answer 1

    new Example().setUp();
    new Example().testExample(); <------------------- Line 68

在第一个语句中，您创建一个新的Example对象并调用setUp()。

在第二个声明中，您创建第二新Example并致电testExample()。在第二个对象中，setUp()尚未被调用，因此driver仍然为空，从而导致异常。

你想做的是

Example ex = new Example();
ex.setUp();
ex.testExample();
ex.isElementPresent();
ex.tearDown();

当应用程序切换到新方法时，Firefox崩溃

1 个答案: