为什么我得到java.lang.IllegalArgumentException：XPath为null时找不到元素错误消息

Question

我创建了一个xpath.properties文件，并将其仅存储在该位置。 格式为：

objuserName=//input[@placeholder='Username']
objpassword=//input[@placeholder='Password']
objloginButton=//a[@onclick='return ValidateLogin()']

编写代码以加载此属性文件，然后输入用户名和密码，然后单击“登录”按钮。 该代码成功打开了浏览器，但是在输入用户名时，它给出了“线程“ main”中的异常java.lang.IllegalArgumentException：XPath为null时找不到元素”。

public class Login {
static Properties objprop = new Properties();

static void PropertyManager() throws IOException{
    File file = new File("C:\\proj-Automation\\financialsys\\abcd\\src\\test\\resources\\xpath.properties");
    FileInputStream fileInput = null;
    try{
        fileInput = new FileInputStream(file);
    }catch (FileNotFoundException e){
    }
    Properties objprop = new Properties();
    try{
        objprop.load(fileInput);
    }catch(IOException e){
        }
//objprop.load(objfile);
}

//When user opens the "firefox" browser
void OpenBrowser(String browsername) throws IOException {
    // TODO Auto-generated method stub
    System.setProperty("webdriver.chrome.driver",config.getParameterValue("chrome_driver_exe_path_32bit"));
    config.driver=new ChromeDriver();
}
public void EnterUserName(String username){
    config.driver.findElement(By.xpath(objprop.getProperty("objuserName"))).sendKeys(username);

}
public void PageMaximise(){
    config.driver.manage().window().maximize();
}
//code for entering the password and clicking on login button
public static void main(String[] args) throws IOException, InterruptedException {
    // TODO Auto-generated method stub

    Login LF = new Login();
    Login.PropertyManager();
    LF.OpenBrowser("CH32");
    LF.EnterURL("http://localhost:90/financialsys");
    LF.PageMaximise();
    LF.EnterUserName("dummycfo");
    LF.EnterPassword("passw0rd");
    LF.ClickLoginButton();
}
}

config.driver.findElement（By.xpath（objprop.getProperty（“ objuserName”）））。sendKeys（username）处的IllegalArgumentException错误可能是什么原因？ 和LF.EnterUserName（“ dummycfo”）;

Answer 1

static void PropertyManager() throws IOException{
    File file = new File("C:\\proj-Automation\\financialsys\\abcd\\src\\test\\resources\\xpath.properties");
    FileInputStream fileInput = null;
    try{
        fileInput = new FileInputStream(file);
    }catch (FileNotFoundException e){
    }
    try{
        objprop.load(fileInput);
    }catch(IOException e){
        }
//objprop.load(objfile);
}
remove Properties objprop = new Properties(); this line from the above method, you are initializing objprop variable with a new object, instead of using the global one which you already have on the top.

Answer 2

请尝试以下代码，通过以下代码片段从属性文件中获取密钥：

public static String fetchLocatorValue(String key) throws IOException {
    FileInputStream file = new FileInputStream(Path of perperty file);
    Properties property = new Properties();
    property.load(file);
    return property.getProperty(key).toString();

}