我已经使用ArrayList和HashSet编写了以下代码。但哈希集无法按预期工作，这意味着它不会删除重复项。但哈希集不允许重复。
**HTML** code
<HTML>
<BODY>
<select id= 'WesInn'>
<option value = 'idli'> IDLI</option>
<option value = 'vada'> VADA</option>
<option value = 'sambhar'> SAMBHAR</option>
<option value = 'Manchurian'> MACHURIAN</option>
<option value = 'idli'> IDLI</option>
<option value = 'sambhar'> SAMBHAR</option>
<option value = 'Tea'> TEA</option>
</select>
</body>
</html>
public class Assgn_DropDownAsc {
//static String text;
public static void main(String[] args) throws InterruptedException {
System.setProperty("webdriver.chrome.driver","./drivers/chromedriver.exe");
WebDriver driver = new ChromeDriver();
driver.get("C:\\Users\\admin\\Desktop\\New folder/Dropdown.html");
List list = new ArrayList ();
LinkedHashSet hs = new LinkedHashSet();
Adding ArrayList elements to the HashSet
//in order to remove the duplicate elements and
//to preserve the insertion order.
hs.addAll(list);
//System.out.println(hs);
//Removing ArrayList elements
hs.clear();
System.out.println(hs);
System.out.println(list);
//Adding LinkedHashSet elements to the ArrayList
hs.addAll(list);
//System.out.println(alloptions.size());
System.out.println(list);
}
}
输出：
[IDLI VADA 桑巴尔 马赫里安 IDLI 桑巴尔 TEA]
答案 0 :(得分：1)
如果您存储输出中提到的String，则您的程序运行正常，看起来您正在打印列表而不是hashSet-
将System.out.println(list);更改为System.out.println(hs);
仅在存储类的对象时才重要，在这种情况下，您应该正确重写equals（）和hashCode（）方法以使用hashSet。
答案 1 :(得分：0)
您可以尝试以下方法：
46
886659200 6000017
11179348 563488904
112321278 512936341
290805893 582941743
981713638 730642556
451606487 821897906
276959357 3493184
348256888 724765346
631201209 265534133
805273482 835799625
7896278 780434096
558123206 298916496
125934025 501664595
3093907 153530369
259080509 243882571
925707583 116455092
424262818 15570209
317202859 428416515
385632830 648856356
430361226 642776630
946215093 428577508
232353771 924654484
210858703 358484249
413081322 682017430
11575422 767941993
771050757 810529689
379926076 348133307
122213626 91834874
71354138 418442988
209818788 131444731
498071620 348763190
33476125 229092671
804771068 917072705
519783854 347122605
119883416 521216836
286529548 492247353
228879775 837125515
532450512 150833406
941425991 107647662
232307150 352065548
737027784 217852390
678923524 583497416
713585999 587088651
448042752 460509778
135584007 849215265
120007541 541958087
输出：
10
50 50
75 50
100 50
50 75
75 75
100 75
1000 1000
1000 1000
1000 1000
1000 1000
答案 2 :(得分：0)
这里有两个示例，说明如何使用 selenium webdriver 将 HashSet 和 LinkedHashSet 与List<WebElement>一起使用：
Java HashSet类用于创建使用哈希表进行存储的集合。它继承了AbstractSet类并实现Set接口。
有关Java HashSet类的要点是：
HashSet类声明：
public class HashSet<E> extends AbstractSet<E> implements Set<E>, Cloneable, Serializable
示例（在Google搜索页内）：
List <WebElement> my_list = driver.findElements(By.xpath("//div[@id='rso']//div[@class='srg']/div[@class='g']//h3/a"));
HashSet<WebElement> values = new HashSet<>(my_list);
for(WebElement value:values)
System.out.println(value.getAttribute("innerHTML"));
控制台输出：
Selenium (software) - Wikipedia
Introduction — Selenium Documentation
Selenium Tutorial
Selenium Testing for Enterprise End-to-End Tests - Tricentis
Selenium - Web Browser Automation
Free Selenium Tutorials - Guru99
Downloads - Selenium
Selenium IDE
Selenium with Python — Selenium Python Bindings 2 documentation
Java LinkedHashSet类是set接口的Hash表和Linked list实现。它继承了HashSet类并实现Set接口。
有关Java HashSet类的要点是：
LinkedHashSet类声明：
public class LinkedHashSet<E> extends HashSet<E> implements Set<E>, Cloneable, Serializable
示例（在Google搜索页内）：
List <WebElement> my_list = driver.findElements(By.xpath("//div[@id='rso']//div[@class='srg']/div[@class='g']//h3/a"));
LinkedHashSet<WebElement> values = new LinkedHashSet<>(my_list);
for(WebElement value:values)
System.out.println(value.getAttribute("innerHTML"));
控制台输出：
Selenium - Web Browser Automation
Selenium IDE
Downloads - Selenium
Introduction — Selenium Documentation
Free Selenium Tutorials - Guru99
Selenium (software) - Wikipedia
Selenium with Python — Selenium Python Bindings 2 documentation
Selenium Tutorial
Selenium Testing for Enterprise End-to-End Tests - Tricentis
答案 3 :(得分：0)
Here is the solution I got.
package qsp;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.support.ui.Select;
public class DropdownAscen {
public static void main(String[] args) {
System.setProperty("webdriver.chrome.driver","./drivers/chromedriver.exe");
WebDriver driver = new ChromeDriver();
driver.get("C:\\Users\\admin\\Desktop\\New folder/Dropdown.html");
WebElement listbox = driver.findElement(By.id("WesInn"));
Select sel = new Select(listbox);
List<WebElement> alllist = sel.getOptions();
int count = alllist.size();
System.out.println(count);
/*for(int i=count-1;i>0;i--)
{
System.out.println(alllist.get(i).getText());
}*/
//Set hs = new HashSet<>(); /we will use this when we don't allow duplicate but not maintain insertion order
Set<String> hs = new TreeSet<>(); //we will use this to maintain duplication & sorting order
for(int i =0; i<count;i++)
{
WebElement option = alllist.get(i);
String txt = option.getText();
hs.add(txt);
//System.out.println(txt);
}
for(String sortedLst:hs)
{
System.out.println(sortedLst);
}
}}
输出
IDLI 马赫里安 桑巴尔 茶 VADA