Selenium WebDriver：检查是否存在元素一段时间循环？

Question

Suppose there is page in which I want to check if an element "abc" is present on the page or not. If the element is not present then I want to click on some other element "xyz", and then new page opens up and again I want to check if the element "abc" is present on the page. If again not present then click on the same element "xyz" and this goes on.

I used while loop and below is the code. Please help me out.

In my below code: "elem_prev" is the element I want to check every time if it is present on the page or not. My code is not working, now it is not able to find the element in the loop, but it should be as it is present on every page. Please help me with the concepts as well. Is the code correct?

It says for the element present in the loop that Unable to locate Element.

Boolean elem_prev = driver.findElements(By.id("TM_TL_DD_WRK_GET_DATA")).size()!=0;
    while(elem_prev==false)
    {
        Thread.sleep(2000);
        driver.findElement(By.className("PSHYPERLINK")).click();

        Thread.sleep(2000);
        Alert a = driver.switchTo().alert();
        a.dismiss();

        Thread.sleep(10000);

        elem_prev = driver.findElements(By.id("TM_TL_DD_WRK_GET_DATA")).size()!=0;
    }

Answer 1

I suggest you find the elements out of the loop like this:

WebElement element1 = driver.findElements(By.id("TM_TL_DD_WRK_GET_DATA"));
WebElement element2 = driver.findElement(By.className("PSHYPERLINK"));

while(element1==false){
    Thread.sleep(2000);
    element2.click();

    Thread.sleep(2000);
    Alert a = driver.switchTo().alert();
    a.dismiss();

    Thread.sleep(10000);

    element1.size()!=0;
}

and then try a SystemOutPrintln(element1); and/or SystemOutPrintln(element2); before the loop starts to be sure it actually finds the element.

If it doesn't print an element, then the problem is not the loop, but the way you try to find the element.

This would be important information as you can then try to find the element in other way.