Question

在尝试初始化Java bean类时遇到问题。我收到空指针异常错误。

下面是代码段。

我有bean xml作为LoginData.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">

<bean id="gmailLogin" class="PojoExample">
    <property name="userName" value="abcd@gmail.com"/>
    <property name="password" value="xyz"/>
</bean>

`

Bean类为`PojoExample

public class PojoExample {
private String userName;
private String password;



public String getUserName() {
    return userName;
}

public void setUserName(String userName) {
    this.userName = userName;
}


public String getPassword() {
    return password;
}

public void setPassword(String password) {
    this.password = password;
}


}

`

我正在尝试通过以下代码初始化bean类（PojoUtilization）

 import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.testng.annotations.Test;

import java.util.concurrent.TimeUnit;


@ContextConfiguration({"classpath:LoginData.xml"})
public class PojoUtilization {

    @Autowired
    PojoExample gmailLogin;

@Test
    public void verify() {
        System.setProperty("webdriver.chrome.driver", "C://Users//E004146//Downloads//workspace/chromedriver.exe");
        WebDriver obj = new ChromeDriver();
        obj.manage().window().maximize();
        obj.get("https://www.google.com/gmail/about/#");
        System.out.println("Clicked on sign in button");
        obj.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);
        WebElement signIn = obj.findElement(By.xpath("//a[contains(text(),'Sign In')]"));
        signIn.click();
        WebElement userName = obj.findElement(By.id("identifierId"));
        userName.sendKeys(gmailLogin.getUserName());
        obj.close();
    }
}

当我尝试执行代码时，我得到一个错误，作为空指针异常。

java.lang.NullPointerException
    at PojoUtilization.verify(PojoUtilization.java:29)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:124)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:583)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:719)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:989)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
    at org.testng.TestRunner.privateRun(TestRunner.java:648)
    at org.testng.TestRunner.run(TestRunner.java:505)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:455)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:450)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:415)
    at org.testng.SuiteRunner.run(SuiteRunner.java:364)

Answer 1

我通过继承AbstractTestNGSpringContextTests类解决了该问题。

public class PojoUtilization extends AbstractTestNGSpringContextTests  {
}

通过继承它，我可以初始化Bean类。

 result = "abcd@gmail.com"

Answer 2

尝试在LoginData.xml文件中添加(<context:annotation-config />)

Answer 3

尝试在 PojoExample 中添加构造函数。没有参数和两个参数。

使用XML配置和注释初始化java bean类时，出现空指针异常

3 个答案: