java - Java/selenium : list.clear(); clearing the result that i was trying to store in map before clearing the list

Question

I Was trying to store country and state values in map with key-value pair every time I loop through one country and get the list of states, I am trying to store them in Map and clearing the list upon selecting other countries but list.clear(); clearing the result that I have already stored in the map as well. please guide me here.

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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 DropdownTest {

    public static void main(String[] args) {

        System.setProperty("webdriver.chrome.driver", "D:\\Java\\Automation\\drivers\\chromedriver.exe");
        WebDriver driver = new ChromeDriver();
        driver.get("https://frontendscript.com/demo/country-dropdown-list-javascript/");
        
        WebElement country = driver.findElement(By.id("country"));
        Select country_sel = new Select(country);
        List<WebElement> countries = country_sel.getOptions();
        
        WebElement state = driver.findElement(By.id("state"));
        Select state_sel = new Select(state);
        
        Map<String, List<String>> result = new HashMap<String, List<String>>();
        
        List<String> state_names = new ArrayList<String>();
        for (WebElement c : countries) {
            if(!(c.getText().equalsIgnoreCase("Select Country"))) {
                
            c.click();
            
            List<WebElement> states = state_sel.getOptions();
        
            for (WebElement s : states) {
                if(!(s.getText().equalsIgnoreCase("Select State"))) {
                    //System.out.println(s.getText());
                    state_names.add(s.getText());
                }
            }
            //System.out.println(state_names);
            result.put(c.getText(), state_names);
            state_names.clear();
            System.out.println(result);
        }}
    }
}

标签： javalistselenium

Answer 1

当您将列表作为值稍后映射和清除列表时，它实际上是指同一个对象。所以清除列表也会影响地图值中的元素。

所以正确的方法是List<String> state_names在for循环内创建。

更新代码：

        Map<String, List<String>> result = new HashMap<String, List<String>>();

        for (WebElement c : countries) {
            if(!(c.getText().equalsIgnoreCase("Select Country"))) {
                
            List<String> state_names = new ArrayList<String>(); // Inside the loop
            
            c.click();
            
            List<WebElement> states = state_sel.getOptions();
        
            for (WebElement s : states) {
                if(!(s.getText().equalsIgnoreCase("Select State"))) {
                    state_names.add(s.getText());
                }
            }
            result.put(c.getText(), state_names);
            System.out.println(result);
            
        }}